Cormac Maher, MD, FAANS, FAAP, FACS

All Publications

• Development of an in vitro ventricular shunt material testing model and utility of PEG as antifouling coating. Journal of neurosurgery. Pediatrics Prindeze, N. J., Szeto, S. G., Glaser, N., Brown, C. B., Azagury, D. E., Maher, C. O. 2024: 1-5

  Abstract

  CSF shunts, most commonly the ventriculoperitoneal shunt, remain a first and last line of management for children and adults with hydrocephalus. However, the failure rates of these shunts are extremely high, leaving many patients with the need for revision surgical procedures. The objective of this study was to develop a model to assess the efficacy of a nonfouling ventricular catheter. A second objective was to test polyethylene glycol (PEG) as an antifouling coating.Microglial cells were grown on medical-grade catheter silicone with biofouling simulated by collagen incubation over a range of concentrations from 31 to 103 µg/ml and durations from 2 to 18 hours. After ideal fouling conditions were identified, catheter silicone was then coated with PEG as an antifouling surface, and cell growth on this surface was compared to that on uncoated standard catheter silicone.Collagen biofouling increased cell growth on silicone surfaces with an ideal concentration of 69 µg/ml and incubation of 6 hours. PEG coating of silicone catheter material yielded 70-fold lower cell growth (p < 0.0001), whereas collagen-fouled PEG-coated silicone yielded 157-fold lower cell growth (p < 0.0001).Catheter coating significantly reduced cell growth, particularly in the setting of biofouling. The application of antifouling surfaces to ventricular shunts shows considerable promise for improving efficacy.

  View details for DOI 10.3171/2024.2.PEDS23456

  View details for PubMedID 38669702

• The role of occipital condyle and atlas anomalies on occipital cervical fusion outcomes in Chiari malformation type I with syringomyelia: a study from the Park-Reeves Syringomyelia Research Consortium. Journal of neurosurgery. Pediatrics Yahanda, A. T., Koueik, J., Ackerman, L. L., Adelson, P. D., Albert, G. W., Aldana, P. R., Alden, T. D., Anderson, R. C., Bauer, D. F., Bethel-Anderson, T., Bierbrauer, K., Brockmeyer, D. L., Chern, J. J., Couture, D. E., Daniels, D. J., Dlouhy, B. J., Durham, S. R., Ellenbogen, R. G., Eskandari, R., Fuchs, H. E., Grant, G. A., Graupman, P. C., Greene, S., Greenfield, J. P., Gross, N. L., Guillaume, D. J., Hankinson, T. C., Heuer, G. G., Iantosca, M., Iskandar, B. J., Jackson, E. M., Jallo, G. I., Johnston, J. M., Kaufman, B. A., Keating, R. F., Khan, N. R., Krieger, M. D., Leonard, J. R., Maher, C. O., Mangano, F. T., Martin, J., McComb, J. G., McEvoy, S. D., Meehan, T., Menezes, A. H., Muhlbauer, M. S., O'Neill, B. R., Olavarria, G., Ragheb, J., Selden, N. R., Shah, M. N., Shannon, C. N., Shimony, J. S., Smyth, M. D., Stone, S. S., Strahle, J. M., Tamber, M. S., Torner, J. C., Tuite, G. F., Tyler-Kabara, E. C., Wait, S. D., Wellons, J. C., Whitehead, W. E., Park, T. S., Limbrick, D. D., Ahmed, R. 2024: 1-9

  Abstract

  Congenital anomalies of the atlanto-occipital articulation may be present in patients with Chiari malformation type I (CM-I). However, it is unclear how these anomalies affect the biomechanical stability of the craniovertebral junction (CVJ) and whether they are associated with an increased incidence of occipitocervical fusion (OCF) following posterior fossa decompression (PFD). The objective of this study was to determine the prevalence of condylar hypoplasia and atlas anomalies in children with CM-I and syringomyelia. The authors also investigated the predictive contribution of these anomalies to the occurrence of OCF following PFD (PFD+OCF).The authors analyzed the prevalence of condylar hypoplasia and atlas arch anomalies for patients in the Park-Reeves Syringomyelia Research Consortium database who underwent PFD+OCF. Condylar hypoplasia was defined by an atlanto-occipital joint axis angle (AOJAA) ≥ 130°. Atlas assimilation and arch anomalies were identified on presurgical radiographic imaging. This PFD+OCF cohort was compared with a control cohort of patients who underwent PFD alone. The control group was matched to the PFD+OCF cohort according to age, sex, and duration of symptoms at a 2:1 ratio.Clinical features and radiographic atlanto-occipital joint parameters were compared between 19 patients in the PFD+OCF cohort and 38 patients in the PFD-only cohort. Demographic data were not significantly different between cohorts (p > 0.05). The mean AOJAA was significantly higher in the PFD+OCF group than in the PFD group (144° ± 12° vs 127° ± 6°, p < 0.0001). In the PFD+OCF group, atlas assimilation and atlas arch anomalies were identified in 10 (53%) and 5 (26%) patients, respectively. These anomalies were absent (n = 0) in the PFD group (p < 0.001). Multivariate regression analysis identified the following 3 CVJ radiographic variables that were predictive of OCF occurrence after PFD: AOJAA ≥ 130° (p = 0.01), clivoaxial angle < 125° (p = 0.02), and occipital condyle-C2 sagittal vertical alignment (C-C2SVA) ≥ 5 mm (p = 0.01). A predictive model based on these 3 factors accurately predicted OCF following PFD (C-statistic 0.95).The authors' results indicate that the occipital condyle-atlas joint complex might affect the biomechanical integrity of the CVJ in children with CM-I and syringomyelia. They describe the role of the AOJAA metric as an independent predictive factor for occurrence of OCF following PFD. Preoperative identification of these skeletal abnormalities may be used to guide surgical planning and treatment of patients with complex CM-I and coexistent osseous pathology.

  View details for DOI 10.3171/2024.1.PEDS23229

  View details for PubMedID 38579359

• Language-discordant care in pediatric neurosurgery: parent and provider perspectives on challenges and multilevel solutions to reduce disparities. Journal of neurosurgery. Pediatrics Ruiz Colon, G. D., Bereknyei Merrell, S., Poon, D. C., Mahaney, K. B., Maher, C. O., Prolo, L. M. 2024: 1-7

  Abstract

  OBJECTIVE: In the United States, Spanish is the second most spoken language, with nearly 42 million individuals speaking Spanish at home. Spanish speakers have been noted to have higher rates of unfavorable neurosurgical outcomes; however, to the authors' knowledge, no study has explored the experiences of patients, caregivers, and providers receiving or delivering neurosurgical care in language-discordant settings. In this study, the authors sought to identify challenges faced by pediatric neurosurgery providers and Spanish-speaking parents communicating with a language barrier and propose solutions to address those challenges.METHODS: Spanish-speaking parents and pediatric neurosurgery providers were invited to participate in semistructured interviews. Purposeful sampling was used to recruit Spanish-speaking parents whose child had recently undergone neurological surgery at the authors' institution and to identify pediatric neurosurgery clinical team members to interview, including physicians, advanced practice providers, and interpreters. Codes were inductively developed and applied to transcripts by two researchers. Thematic analysis was conducted to identify challenges faced by parents and providers.RESULTS: Twenty individuals were interviewed, including parents (n = 8), advanced practice providers (n = 5), physicians (n = 3), interpreters (n = 2), a social worker (n = 1), and a nurse (n = 1). Three challenges were identified. 1) Compared with English-speaking parents, providers noted that Spanish-speaking parents were less likely to ask questions or raise new concerns. Concurrently, Spanish-speaking parents expressed a desire to better understand their child's future medical needs, care, and development. 2) There is a dearth of high-quality resources available in the Spanish language to supplement patient and parent neurosurgical education. 3) Both parents and providers invariably prefer in-person interpreters; however, their availability is limited.CONCLUSIONS: Three challenges were identified by Spanish-speaking parents of pediatric neurosurgery patients and providers when receiving or delivering care through a language barrier. The authors discuss multilevel solutions that, if deployed, could directly address these shared challenges. Furthermore, optimizing communication may help mitigate the disparities experienced by non-English-speaking Hispanic/Latino individuals when receiving neurosurgical care.

  View details for DOI 10.3171/2024.1.PEDS23435

  View details for PubMedID 38518279

• Influence of socioeconomic status on clinical outcomes of diffuse midline glioma and diffuse intrinsic pontine glioma. Journal of neurosurgery. Pediatrics Lee, J. H., Holste, K. G., Bah, M. G., Franson, A. T., Garton, H. J., Maher, C. O., Muraszko, K. M. 2024: 1-9

  Abstract

  Given the lack of a definitive treatment and the poor prognosis of patients with diffuse midline glioma (DMG) and diffuse intrinsic pontine glioma (DIPG), socioeconomic status (SES) may affect treatment access and therefore survival. Therefore, this study aimed to examine the relationship between SES and treatment modalities, progression-free survival (PFS), and overall survival (OS) in children with DMG/DIPG.A retrospective, single-institution review was conducted of medical records of patients ≤ 18 years of age who had DMG or DIPG that was diagnosed between 2000 and 2022. Patient demographics, surgical interventions, chemotherapy, radiation therapy, clinical trial enrollment, and medical care-related travel were extracted. SES variables (education and mean income) for associated patient census tracts were collected and stratified. Statistical analysis using unpaired t-tests, chi-square analysis, and log-rank tests was conducted.Of the 96 patients who met the inclusion criteria, the majority were female (59%) and non-Hispanic White (57%). The median PFS, median OS, and time from diagnosis to treatment did not differ between races/ethnicities or sex. Ninety-one of 96 patients had census tract data available. Patients from higher-income census tracts (> 50% of families with annual household income greater than $50,000) had a longer median OS (480 vs 235 days, p < 0.001) and traveled significantly longer distances for medical care (1550 vs 1114 miles, p = 0.048) than families from lower-income census tracts. Patients from the highest education quartile traveled significantly farther for treatment than the lowest education quartile (mean 2964 vs 478 miles, p = 0.047). Patients who received both oral and intravenous chemotherapy were more likely to be from higher-income census tracts than those who received intravenous or no chemotherapy. Duration of PFS, rates of clinical trial enrollment, biopsy rates, H3K27 mutation status, ventriculoperitoneal shunt placement rates, and radiotherapy rates were not associated with SES variables.Patients from families from higher-income census tracts experienced longer OS and traveled farther for treatment. Patients from families from higher-education-level census tracts traveled more often for treatment. The authors' findings suggest that SES influences DMG and DIPG OS. More studies should be done to understand the role of SES in the outcomes of children with DMG/DIPG.

  View details for DOI 10.3171/2023.10.PEDS23118

  View details for PubMedID 38489807

• "Ventricular Volume Change as a Predictor of Shunt-Dependent Hydrocephalus in Aneurysmal Subarachnoid Hemorrhage" (vol 180,17880, 2022) WORLD NEUROSURGERY Talbot-Stetsko, H. K., Pawlowski, K. D., Aaron, B. L., Adapa, A. R., Altshuler, D. B., Srinivasan, S., Pandey, A. S., Maher, C. O., Hollon, T. C., Khalsa, S. S. 2023; 180: 224

  View details for DOI 10.1016/j.wneu.2023.06.083

  View details for Web of Science ID 001138975900001

  View details for PubMedID 37821295

• In Reply: Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Patients With Chiari Malformation: Surgical Interventions. Neurosurgery Bauer, D. F., Pattisapu, J. V., Ackerman, L. L., Infinger, L. K., Jackson, E. M., Jernigan, S., Maher, C. O., Niazi, T., Qaiser, R., Quinsey, C., Raskin, J. S., Rocque, B. G., Silberstein, H., Vachhrajani, S. 2023

  View details for DOI 10.1227/neu.0000000000002766

  View details for PubMedID 37962335

• Attenuation of ventriculomegaly and iron overload after intraventricular hemorrhage by membrane attack complex inhibition. Journal of neurosurgery Holste, K. G., Ye, F., Koduri, S., Garton, H. J., Maher, C. O., Keep, R. F., Hua, Y., Xi, G. 2023: 1-11

  Abstract

  The pathophysiology of posthemorrhagic hydrocephalus (PHH) is not well understood, but recent data suggest blood components play a significant role. This study aimed to understand the timing of membrane attack complex (MAC) activation after intraventricular hemorrhage (IVH) and the effect of MAC inhibition on PHH development.This study was composed of four parts. First, 24 young adult male rats underwent stereotactic intraventricular injection of autologous blood or saline and MRI on day 1, 3, or 7 after hemorrhage. Second, 18 rats underwent intraventricular injection of saline, autologous blood with aurin tricarboxylic acid (ATA) in vehicle, or autologous blood with vehicle and underwent serial MRI studies on days 1 and 3 after hemorrhage. Third, 12 rats underwent intraventricular injections as above and MRI 2 hours after hemorrhage. Finally, 24 rats underwent the intraventricular injections as above, as well as serial MRI studies on days 1, 7, 14, and 28 after hemorrhage. The MR images were used to calculate ventricular volume and iron deposition. Open field testing was performed to assess functional outcomes. Outcomes on day 28 were reported as a ratio to the animal's baseline values and normalized via log-transformation. Statistical analysis included the Shapiro-Wilk tests for normality and t-tests and 1-way analysis of variance for 2 and 3 groups of continuous variables, respectively.MAC was found within the hematoma 1 day after hemorrhage and persisted until day 7. Administration of ATA resulted in similar intraventricular hematoma volumes compared to vehicle 2 hours after hemorrhage. At 1 and 3 days after hemorrhage, ATA administration resulted in significantly smaller ventricular volumes and less hemolysis within the hematoma than in the vehicle animals. Administration of ATA also resulted in significantly smaller ventriculomegaly and less iron deposition in the periventricular area than in the vehicle rats 28 days after hemorrhage. Functionally, ATA rats were significantly faster, traveled longer distances, and spent less time resting than vehicle rats at 28 days.MAC was activated early and persisted within the hematoma until day 7 after IVH. MAC inhibition attenuated hemolysis in the clot and ventriculomegaly acutely after IVH. One month after hemorrhage, MAC inhibition attenuated ventriculomegaly and iron accumulation and improved functional outcomes.

  View details for DOI 10.3171/2023.8.JNS23667

  View details for PubMedID 37948699

• Sports Participation and Neurological Injuries in Pediatric Patients With Chiari I Malformation NEUROSURGERY Wieland, C. M., Holste, K. G., Selzer, B., Garton, H. L., Muraszko, K. M., Maher, C. O. 2023; 93 (3): 646-653

  Abstract

  Currently, there is no consensus recommendation regarding the safety of sports participation for pediatric patients with Chiari I malformation (CM-I).To prospectively survey the treated and untreated patients with CM-I to define the risk of sports-associated neurological injury.A prospective survey was administered to 744 pediatric patients at one neurosurgery clinic between 2010 and 2021. Data were recorded on demographic information, imaging characteristics, treatment, sports participation, and presence of sports-related neurological injury. Patients with incomplete data were called. Two hundred seven patients completed at least 1 subsequent survey and were prospectively followed (mean 1.6 years).Of 744 patients with completed surveys, 462 participated in sports. Sports participants were more likely to be older at presentation ( P < .001) and have rounded cerebellar tonsil morphology ( P < .001). Seasons of sports played before and after CM-I decompression (CMD) totaled 5918.7 and 936, respectively. There were 84 sports-related concussions among 55 patients; 79 in untreated patients and 5 after CMD. For all sports participants, the concussion rate was 12.3/1000 seasons of all sports, 9.2/1000 seasons of limited-contact sports, and 13.8/1000 of contact sports. The concussion rate after CMD was 5.3/1000 seasons of all sports, 9.2/1000 seasons of limited-contact sports, and 7.1/1000 seasons of contact sports. There were no reports of long-lasting neurological issues postconcussion or of permanent spinal cord injury.No permanent or catastrophic sports-associated neurological injuries were reported. The concussion rates in treated and untreated patients with CM-I were low. Therefore, sports participation in this population should be permitted in most cases.

  View details for DOI 10.1227/neu.0000000000002468

  View details for Web of Science ID 001050079800034

  View details for PubMedID 36961215

• Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Patients With Chiari Malformation: Surgical Interventions. Neurosurgery Pattisapu, J. V., Ackerman, L. L., Infinger, L. K., Maher, C. O., Quinsey, C., Rocque, B. G., Silberstein, H., Jackson, E. M., Jernigan, S., Niazi, T., Qaiser, R., Raskin, J. S., Vachhrajani, S., Bauer, D. F. 2023

  Abstract

  BACKGROUND: Chiari malformation type I (CIM) diagnoses have increased in recent years. Controversy regarding the best operative management prompted a review of the literature to offer guidance on surgical interventions.OBJECTIVE: To assess the literature to determine (1) whether posterior fossa decompression or posterior fossa decompression with duraplasty is more effective in preoperative symptom resolution; (2) whether there is benefit from cerebellar tonsillar resection/reduction; (3) the role of intraoperative neuromonitoring; (4) in patients with a syrinx, how long should a syrinx be observed for improvement before additional surgery is performed; and 5) what is the optimal duration of follow-up care after preoperative symptom resolution.METHODS: A systematic review was performed using the National Library of Medicine/PubMed and Embase databases for studies on CIM in children and adults. The most appropriate surgical interventions, the use of neuromonitoring, and clinical improvement during follow-up were reviewed for studies published between 1946 and January 23, 2021.RESULTS: A total of 80 studies met inclusion criteria. Posterior fossa decompression with or without duraplasty or cerebellar tonsil reduction all appeared to show some benefit for symptom relief and syrinx reduction. There was insufficient evidence to determine whether duraplasty or cerebellar tonsil reduction was needed for specific patient groups. There was no strong correlation between symptom relief and syringomyelia resolution. Many surgeons follow patients for 6-12 months before considering reoperation for persistent syringomyelia. No benefit or harm was seen with the use of neuromonitoring.CONCLUSION: This evidence-based clinical guidelines for the treatment of CIM provide 1 Class II and 4 Class III recommendations. In patients with CIM with or without syringomyelia, treatment options include bone decompression with or without duraplasty or cerebellar tonsil reduction. Improved syrinx resolution may potentially be seen with dural patch grafting. Symptom resolution and syrinx resolution did not correlate directly. Reoperation for a persistent syrinx was potentially beneficial if the syrinx had not improved 6 to 12 months after the initial operation. The full guidelines can be seen online at https://www.cns.org/guidelines/browse-guidelines-detail/3-surgical-interventions.

  View details for DOI 10.1227/neu.0000000000002635

  View details for PubMedID 37646504

• Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Patients With Chiari Malformation: Symptoms. Neurosurgery Jackson, E. M., Jernigan, S., Raskin, J. S., Ackerman, L. L., Infinger, L. K., Maher, C. O., Niazi, T., Pattisapu, J. V., Qaiser, R., Quinsey, C., Rocque, B. G., Silberstein, H., Vachhrajani, S., Bauer, D. F. 2023

  Abstract

  BACKGROUND: Chiari I malformation (CIM) is characterized by descent of the cerebellar tonsils through the foramen magnum, potentially causing symptoms from compression or obstruction of the flow of cerebrospinal fluid. Diagnosis and treatment of CIM is varied, and guidelines produced through systematic review may be helpful for clinicians.OBJECTIVE: To perform a systematic review of the medical literature to answer specific questions on the diagnosis and treatment of CIM.METHODS: PubMed and Embase were queried between 1946 and January 23, 2021, using the search strategies provided in Appendix I of the full guidelines.RESULTS: The literature search yielded 430 abstracts, of which 79 were selected for full-text review, 44 were then rejected for not meeting the inclusion criteria or for being off-topic, and 35 were included in this systematic review.CONCLUSION: Four Grade C recommendations were made based on Class III evidence, and 1 question had insufficient evidence. The full guidelines can be seen online at https://www.cns.org/guidelines/browse-guidelines-detail/2-symptoms.

  View details for DOI 10.1227/neu.0000000000002634

  View details for PubMedID 37646519

• Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Patients With Chiari Malformation: Diagnosis. Neurosurgery Bauer, D. F., Niazi, T., Qaiser, R., Infinger, L. K., Vachhrajani, S., Ackerman, L. L., Jackson, E. M., Jernigan, S., Maher, C. O., Pattisapu, J. V., Quinsey, C., Raskin, J. S., Rocque, B. G., Silberstein, H. 2023

  Abstract

  BACKGROUND: Chiari I malformation (CIM) is characterized by descent of the cerebellar tonsils through the foramen magnum, potentially causing symptoms from compression or obstruction of the flow of cerebrospinal fluid. Diagnosis and treatment of CIM is varied, and guidelines produced through systematic review may be helpful for clinicians.OBJECTIVE: To perform a systematic review of the medical literature to answer specific questions on the diagnosis and treatment of CIM.METHODS: PubMed and Embase were queried between 1946 and January 23, 2021, using the search strategies provided in Appendix I of the full guidelines.RESULTS: The literature search yielded 567 abstracts, of which 151 were selected for full-text review, 109 were then rejected for not meeting the inclusion criteria or for being off-topic, and 42 were included in this systematic review.CONCLUSION: Three Grade C recommendations were made based on Level III evidence. The full guidelines can be seen online at https://www.cns.org/guidelines/browse-guidelines-detail/1-imaging.

  View details for DOI 10.1227/neu.0000000000002633

  View details for PubMedID 37646512

• Ventriculoatrial and ventriculoperitoneal shunt malfunction and infection in infants with necrotizing enterocolitis. Journal of neurosurgery. Pediatrics Holste, K. G., Vernamonti, J., Bah, M. G., Muraszko, K. M., Gadepalli, S. K., Maher, C. O., Garton, H. J. 2023: 1-7

  Abstract

  Necrotizing enterocolitis (NEC) and posthemorrhagic hydrocephalus are both conditions that can affect preterm infants. The peritoneum is the preferred terminus for shunt placement, but another terminus is sometimes used due to subjective concerns about infection and complications related to NEC. The aim of this study was to examine the rates of ventriculoatrial (VA) and ventriculoperitoneal (VP) shunt infection and failure in pediatric patients with a history of NEC.A single-center retrospective review of medical records from 2009 to 2021 was performed to identify pediatric patients with NEC who underwent shunt placement before 2 years of age. Patients were excluded if shunt placement preceded NEC diagnosis. Patient demographic characteristics, timing of shunt placement, type of shunt, shunt infections or revisions, and timing and management of NEC were extracted. The Student t-test and Fisher exact test were used to calculate significance. Kaplan-Meier curves were calculated.Twenty-two patients met the inclusion criteria. Most patients underwent VP shunt placement (16 [71.4%]). Patients who underwent surgical management of NEC compared with those who underwent medical management were more likely to have a VA shunt placed (p = 0.02). One VA shunt and 3 VP shunts became infected during follow-up (p = 0.7). The mean time until infection was not significantly different between VA and VP shunts (p = 0.73). Significantly more VA shunts required revision (83% vs 31%, p = 0.04), and VA shunts had a significantly shorter time until failure (3.0 ± 0.8 vs 46.3 ± 7.55 months, p = 0.03).VP shunts had a significantly longer time until failure than VA shunts; these shunts had similar infection rates in infants with prior NEC. When feasible, neurosurgeons and pediatric general surgeons can consider placing a VP shunt even if the patient has a history of NEC.

  View details for DOI 10.3171/2023.6.PEDS23145

  View details for PubMedID 37542448

• Pediatric Moyamoya Revascularization Perioperative Care: A Modified Delphi Study. Neurocritical care Sun, L. R., Jordan, L. C., Smith, E. R., Aldana, P. R., Kirschen, M. P., Guilliams, K., Gupta, N., Steinberg, G. K., Fox, C., Harrar, D. B., Lee, S., Chung, M. G., Dirks, P., Dlamini, N., Maher, C. O., Lehman, L. L., Hong, S. J., Strahle, J. M., Pineda, J. A., Beslow, L. A., Rasmussen, L., Mailo, J., Piatt, J., Lang, S. S., Adelson, P. D., Dewan, M. C., Mineyko, A., McClugage, S., Vadivelu, S., Dowling, M. M., Hersh, D. S. 2023

  Abstract

  Surgical revascularization decreases the long-term risk of stroke in children with moyamoya arteriopathy but can be associated with an increased risk of stroke during the perioperative period. Evidence-based approaches to optimize perioperative management are limited and practice varies widely. Using a modified Delphi process, we sought to establish expert consensus on key components of the perioperative care of children with moyamoya undergoing indirect revascularization surgery and identify areas of equipoise to define future research priorities.Thirty neurologists, neurosurgeons, and intensivists practicing in North America with expertise in the management of pediatric moyamoya were invited to participate in a three-round, modified Delphi process consisting of a 138-item practice patterns survey, anonymous electronic evaluation of 88 consensus statements on a 5-point Likert scale, and a virtual group meeting during which statements were discussed, revised, and reassessed. Consensus was defined as ≥ 80% agreement or disagreement.Thirty-nine statements regarding perioperative pediatric moyamoya care for indirect revascularization surgery reached consensus. Salient areas of consensus included the following: (1) children at a high risk for stroke and those with sickle cell disease should be preadmitted prior to indirect revascularization; (2) intravenous isotonic fluids should be administered in all patients for at least 4 h before and 24 h after surgery; (3) aspirin should not be discontinued in the immediate preoperative and postoperative periods; (4) arterial lines for blood pressure monitoring should be continued for at least 24 h after surgery and until active interventions to achieve blood pressure goals are not needed; (5) postoperative care should include hourly vital signs for at least 24 h, hourly neurologic assessments for at least 12 h, adequate pain control, maintaining normoxia and normothermia, and avoiding hypotension; and (6) intravenous fluid bolus administration should be considered the first-line intervention for new focal neurologic deficits following indirect revascularization surgery.In the absence of data supporting specific care practices before and after indirect revascularization surgery in children with moyamoya, this Delphi process defined areas of consensus among neurosurgeons, neurologists, and intensivists with moyamoya expertise. Research priorities identified include determining the role of continuous electroencephalography in postoperative moyamoya care, optimal perioperative blood pressure and hemoglobin targets, and the role of supplemental oxygen for treatment of suspected postoperative ischemia.

  View details for DOI 10.1007/s12028-023-01788-0

  View details for PubMedID 37470933

  View details for PubMedCentralID 5443666

• A comparison of ventricular volume and linear indices in predicting shunt dependence in aneurysmal subarachnoid hemorrhage. World neurosurgery: X Talbot-Stetsko, H. K., Hollon, T. C., Maher, C. O., Pandey, A. S., Khalsa, S. S. 2023; 19: 100181

  Abstract

  Background: Guidelines for determining shunt dependence after aneurysmal subarachnoid hemorrhage (aSAH) remain unclear. We previously demonstrated change in ventricular volume (VV) between head CT scans taken pre- and post-EVD clamping was predictive of shunt dependence in aSAH. We sought to compare the predictive value of this measure to more commonly used linear indices.Methods: We retrospectively analyzed images of 68 patients treated for aSAH who required EVD placement and underwent one EVD weaning trial, 34 of whom underwent shunt placement. We utilized an in-house MATLAB program to analyze VV and supratentorial VV (sVV) in head CT scans obtained before and after EVD clamping. Evans' index (EI), frontal and occipital horn ratio (FOHR), Huckman's measurement, minimum lateral ventricular width (LV-Min.), and lateral ventricle body span (LV-Body) were measured using digital calipers in PACS. Receiver operating curves (ROC) were generated.Results: Area under the ROC curves (AUC) for the change in VV, sVV, EI, FOHR, Huckman's, LV-Min., and LV-Body with clamping were 0.84, 0.84, 0.65, 0.71.0.69, 0.67, and 0.66, respectively. AUC for post-clamp scan measurements were 0.75, 0.75, 0.74, 0.72, 0.72, 0.70, and 0.75, respectively.Conclusion: VV change with EVD clamping was more predictive of shunt dependence in aSAH than change in linear measurements with clamping and all post-clamp measurements. Measurement of ventricular size on serial imaging with volumetrics or linear indices utilizing multidimensional data points may therefore be a more robust metric than unidimensional linear indices in predicting shunt dependence in this cohort. Prospective studies are needed for validation.

  View details for DOI 10.1016/j.wnsx.2023.100181

  View details for PubMedID 37026086

• Sports Participation and Sports-Related Neurologic Injuries in Pediatric Patients With Arachnoid Cysts. Neurosurgery Lee, J. H., Holste, K. G., Selzer, B. J., Garton, H. J., Muraszko, K. M., Maher, C. O. 2023

  Abstract

  BACKGROUND: Currently, there is no consensus recommendation regarding the safety of sports participation for pediatric patients with arachnoid cysts (ACs).OBJECTIVE: To prospectively survey patients with ACs to define the risk of sports-associated neurologic injury in untreated and treated patients.METHODS: A prospectively administered survey was given to all patients diagnosed with an AC who presented to a single pediatric neurosurgery clinic between December 2010 and December 2021. Data were recorded on demographic information, imaging characteristics, treatment, sports participation, and presence of sports-related neurologic injury. The type and date of surgery for the AC were noted if surgery was performed.RESULTS: Of the 303 patients with completed surveys, 189 patients participated in sports, and 94 patients had prospective data available. There was no significant difference in cyst location or Galassi score between patients who did and did not participate in contact vs noncontact sports and those who did and did not experience a concussion. A cumulative total of 2700.5 seasons of sports were played (2499.7 in untreated and 200.8 in treated patients). There were 44 sports-related concussions among 34 patients: 43 in untreated patients and 1 in a treated patient. For all participants, the concussion rate was 16.3 per 1000 seasons of all sports and 14.8 per 1000 seasons of contact sports. The concussion rate after AC treatment was 4.9 per 1000 seasons of all sports. Three patients experienced sports-related AC rupture or hemorrhage, none of which required surgery or resulted in lasting neurologic symptoms or deficits.CONCLUSION: The rates of sports-related concussion and cyst rupture in patients with AC in both treated and untreated populations were low. We advocate for a generally permissive posture toward sports participation in this population.

  View details for DOI 10.1227/neu.0000000000002537

  View details for PubMedID 37199501

• Epidemiology of Chiari I Malformation and Syringomyelia NEUROSURGERY CLINICS OF NORTH AMERICA Holste, K. G., Muraszko, K. M., Maher, C. O. 2023; 34 (1): 9-15

  Abstract

  Chiari I malformation is a common condition seen by adult and pediatric neurosurgeons. With increased utilization of MRI over time, incidental findings of Chiari I malformation are occurring more frequently. The prevalence of symptomatic Chiari I malformation is much smaller than that of asymptomatic Chiari I malformation. The prevalence of Chiari I malformation-associated syringomyelia is likely overestimated in the literature. The epidemiology of Chiari I malformation and associated syringomyelia differs based on age, sex, ethnicity, race, and socioeconomic status. The natural history of Chiari I malformation and associated syringomyelia appears to be quite benign as few patients who are managed nonsurgically later require surgical intervention.

  View details for DOI 10.1016/j.nec.2022.08.001

  View details for Web of Science ID 000917197500003

  View details for PubMedID 36424068

• Indications for arachnoid cyst surgery JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O. 2022; 30 (3): 135-137

  View details for DOI 10.3171/2022.1.PEDS21540

  View details for Web of Science ID 000874888600001

  View details for PubMedID 35594881

• Incidental Murmur in a Preadolescent Boy JAMA CARDIOLOGY Lam, J. W., Saleh, S., Maher, C. O. 2022; 7 (7): e220927

  View details for DOI 10.1001/jamacardio.2022.0927

  View details for Web of Science ID 000825677500027

  View details for PubMedID 35829714

• Subdural hematoma prevalence and long-term developmental outcomes in patients with benign expansion of the subarachnoid spaces JOURNAL OF NEUROSURGERY-PEDIATRICS Holste, K. G., Wieland, C. M., Ibrahim, M., Parmar, H. A., Saleh, S., Garton, H. L., Maher, C. O. 2022; 29 (5): 536-542

  Abstract

  Benign expansion of the subarachnoid spaces (BESS) is a condition seen in macrocephalic infants. BESS is associated with mild developmental delays which tend to resolve within a few years. It is accepted that patients with BESS are at increased risk of spontaneous subdural hematomas (SDHs), although the exact pathophysiology is not well understood. The prevalence of spontaneous SDH in BESS patients is poorly defined, with only a few large single-center series published. In this study the authors aimed to better define BESS prevalence and developmental outcomes through the longitudinal review of a large cohort of BESS patients.A large retrospective review was performed at a single institution from 1995 to 2020 for patients 2 years of age or younger with a diagnosis of BESS by neurology or neurosurgery and head circumference > 85th percentile. Demographic data, head circumference, presence of developmental delay, occurrence of SDH, and need for surgery were extracted from patient charts. The subarachnoid space (SAS) size was measured from the available MR images, and the sizes of those who did and did not develop SDH were compared.Free text search revealed BESS mentioned within the medical records of 1410 of 2.6 million patients. After exclusion criteria, 480 patients remained eligible for the study. Thirty-two percent (n = 154) of patients were diagnosed with developmental delay, most commonly gross motor delay (53%). Gross motor delay resolved in 86% of patients at a mean age of 22.2 months. The prevalence of spontaneous SDH in this BESS population over a period of 25 years was 8.1%. There was no significant association between SAS size and SDH formation.This study represents results for one of the largest cohorts of patients with BESS at a single institution. Gross motor delay was the most common developmental delay diagnosed, and a majority of patients had resolution of their delay. These data support that children with BESS have a higher prevalence of SDH than the general pediatric population, although SAS size was not significantly associated with SDH development.

  View details for DOI 10.3171/2021.12.PEDS21436

  View details for Web of Science ID 000795683700008

  View details for PubMedID 35148506

• The use of big data for improving understanding of the natural history of neurosurgical disease NEUROSURGICAL FOCUS Holste, K. G., Chopra, Z., Saleh, S., Saadeh, Y. S., Park, P., Maher, C. O. 2022; 52 (4): E2

  View details for DOI 10.3171/2022.1.FOCUS21712

  View details for Web of Science ID 000781114400005

  View details for PubMedID 35364579

• Superficial abdominal reflex in syringomyelia: Associations with Chiari I malformation JOURNAL OF CLINICAL NEUROSCIENCE Nadel, J. L., Ziats, C., Mossner, J. M., Starr, J. B., Smith, B. W., Kelly, M. P., Muraszko, K. M., Farley, F. A., Maher, C. O., Garton, H. L., Strahle, J. M. 2022; 98: 1-5

  Abstract

  An abnormal or absent superficial abdominal reflex (SAR) may be associated with an underlying spinal cord syrinx. The sensitivity of an abnormal or absent SAR and the relationship to Chiari malformation type I (CM-I) or syrinx morphology has not been studied. We aimed to describe the relationship between SAR abnormalities and syrinx size, location, and etiology. Children who underwent brain or c-spine MRI over 11 years were reviewed in this retrospective cohort study. Patients with idiopathic and CM-I-associated syringes (axial diameter ≥ 3 mm) were included. Clinical examination findings (including SAR) and imaging characteristics were analyzed. Of 271 patients with spinal cord syrinx, 200 had either CM-I-associated or idiopathic syrinx, and 128 of these patients had SAR-evaluation documentation. Forty-eight percent (62/128) had an abnormal or absent reflex. Abnormal/absent SAR was more common in patients with CM-I-associated syrinx (61%) compared with idiopathic syrinx (22%) (P < 0.0001). Abnormal/absent SAR was associated with wider syringes (P < 0.001), longer syringes (P < 0.05), and a more cranial location of the syrinx (P < 0.0001). Controlling for CM-I, scoliosis, age, sex, cranial extent of syrinx, and syrinx dimensions, CM-I was independently associated with abnormal or absent SAR (OR 4.2, 95% CI 1.4-14, P < 0.01). Finally, the sensitivity of SAR for identifying a patient with syrinx was 48.1%. An abnormal/absent SAR was present in most patients with CM-I-associated syrinx but in a minority of patients with idiopathic syrinx. This has implications for pathophysiology of CM-I-associated syrinx and in guiding clinical care of patients presenting with syrinx.

  View details for DOI 10.1016/j.jocn.2021.12.037

  View details for Web of Science ID 001043687800001

  View details for PubMedID 35114475

• Program Director Patient Safety and Quality Educators Network: A Learning Collaborative to Improve Resident and Fellow Physician Engagement Journal of Graduate Medical Education Wagner , R., Weiss , K., Headrick , L., Jaffe , R., Fant , A., Sullivan , A., Maher , C., Donato , J., Benzil , D., Miltner , R., Hemphill , R., Holmboe , E., Clewett , E., Clements , D., Brigham , T., Arora , S. 2022
• Intern Year Surviving Neurosurgery Ward , A., Maher , C. Springer. 2022
• Ventricular Volume Change as a Predictor of Shunt-Dependent Hydrocephalus in Aneurysmal Subarachnoid Hemorrhage WORLD NEUROSURGERY Talbot-Stetsko, H. K., Raue, K. D., Aaron, B. L., Adapa, A. R., Altshuler, D. B., Srinivasan, S., Pandey, A. S., Maher, C. O., Hollon, T. C., Khalsa, S. S. 2022; 157: E57-E65

  Abstract

  Hydrocephalus is a common complication of aneurysmal subarachnoid hemorrhage (aSAH) that often requires acute placement of an external ventricular drain (EVD). The current systems available for determining which patients will require long-term cerebrospinal fluid diversion remain subjective. We investigated the ventricular volume change (ΔVV) after EVD clamping as an objective predictor of shunt dependence in patients with aSAH.We performed a retrospective medical record review and image analysis of patients treated for aSAH at a single academic institution who had required EVD placement for acute hydrocephalus and had undergone 1 EVD weaning trial. Head computed tomography (CT) scans obtained before and after EVD clamping were analyzed using a custom semiautomated MATLAB program (MathWorks, Natick, Massachusetts, USA), which segments each CT scan into 5 tissue types using k-means clustering. Differences in the pre- and postclamp ventricular volumes were calculated.A total of 34 patients with an indwelling shunt met the inclusion criteria and were sex- and age-matched to 34 controls without a shunt. The mean ΔVV was 19.8 mL in the shunt patients and 3.8 mL in the nonshunt patients (P < 0.0001). The area under the receiver operating characteristic curve was 0.84. The optimal ΔVV threshold was 11.4 mL, with a sensitivity of 76.5% and specificity of 88.2% for predicting shunt dependence. The mean ΔVV was significantly greater for the patients readmitted for shunt placement compared with the patients not requiring cerebrospinal fluid diversion (18.69 mL vs. 3.84 mL; P = 0.005). Finally, 70% of the patients with delayed shunt dependence had ΔVV greater than the identified threshold.The ΔVV volume between head CT scans taken before and after EVD clamping was predictive of early and delayed shunt dependence.

  View details for DOI 10.1016/j.wneu.2021.09.085

  View details for Web of Science ID 000747884600007

  View details for PubMedID 34583001

• Socioeconomic and demographic factors in the diagnosis and treatment of Chiari malformation type I and syringomyelia. Journal of neurosurgery. Pediatrics Akbari, S. H., Rizvi, A. A., CreveCoeur, T. S., Han, R. H., Greenberg, J. K., Torner, J., Brockmeyer, D. L., Wellons, J. C., Leonard, J. R., Mangano, F. T., Johnston, J. M., Shah, M. N., Iskandar, B. J., Ahmed, R., Tuite, G. F., Kaufman, B. A., Daniels, D. J., Jackson, E. M., Grant, G. A., Powers, A. K., Couture, D. E., Adelson, P. D., Alden, T. D., Aldana, P. R., Anderson, R. C., Selden, N. R., Bierbrauer, K., Boydston, W., Chern, J. J., Whitehead, W. E., Dauser, R. C., Ellenbogen, R. G., Ojemann, J. G., Fuchs, H. E., Guillaume, D. J., Hankinson, T. C., O'Neill, B. R., Iantosca, M., Oakes, W. J., Keating, R. F., Klimo, P., Muhlbauer, M. S., McComb, J. G., Menezes, A. H., Khan, N. R., Niazi, T. N., Ragheb, J., Shannon, C. N., Smith, J. L., Ackerman, L. L., Jea, A. H., Maher, C. O., Narayan, P., Albert, G. W., Stone, S. S., Baird, L. C., Gross, N. L., Durham, S. R., Greene, S., McKinstry, R. C., Shimony, J. S., Strahle, J. M., Smyth, M. D., Dacey, R. G., Park, T. S., Limbrick, D. D. 2021: 1-10

  Abstract

  OBJECTIVE: The goal of this study was to assess the social determinants that influence access and outcomes for pediatric neurosurgical care for patients with Chiari malformation type I (CM-I) and syringomyelia (SM).METHODS: The authors used retro- and prospective components of the Park-Reeves Syringomyelia Research Consortium database to identify pediatric patients with CM-I and SM who received surgical treatment and had at least 1 year of follow-up data. Race, ethnicity, and insurance status were used as comparators for preoperative, treatment, and postoperative characteristics and outcomes.RESULTS: A total of 637 patients met inclusion criteria, and race or ethnicity data were available for 603 (94.7%) patients. A total of 463 (76.8%) were non-Hispanic White (NHW) and 140 (23.2%) were non-White. The non-White patients were older at diagnosis (p = 0.002) and were more likely to have an individualized education plan (p < 0.01). More non-White than NHW patients presented with cerebellar and cranial nerve deficits (i.e., gait ataxia [p = 0.028], nystagmus [p = 0.002], dysconjugate gaze [p = 0.03], hearing loss [p = 0.003], gait instability [p = 0.003], tremor [p = 0.021], or dysmetria [p < 0.001]). Non-White patients had higher rates of skull malformation (p = 0.004), platybasia (p = 0.002), and basilar invagination (p = 0.036). Non-White patients were more likely to be treated at low-volume centers than at high-volume centers (38.7% vs 15.2%; p < 0.01). Non-White patients were older at the time of surgery (p = 0.001) and had longer operative times (p < 0.001), higher estimated blood loss (p < 0.001), and a longer hospital stay (p = 0.04). There were no major group differences in terms of treatments performed or complications. The majority of subjects used private insurance (440, 71.5%), whereas 175 (28.5%) were using Medicaid or self-pay. Private insurance was used in 42.2% of non-White patients compared to 79.8% of NHW patients (p < 0.01). There were no major differences in presentation, treatment, or outcome between insurance groups. In multivariate modeling, non-White patients were more likely to present at an older age after controlling for sex and insurance status (p < 0.01). Non-White and male patients had a longer duration of symptoms before reaching diagnosis (p = 0.033 and 0.004, respectively).CONCLUSIONS: Socioeconomic and demographic factors appear to influence the presentation and management of patients with CM-I and SM. Race is associated with age and timing of diagnosis as well as operating room time, estimated blood loss, and length of hospital stay. This exploration of socioeconomic and demographic barriers to care will be useful in understanding how to improve access to pediatric neurosurgical care for patients with CM-I and SM.

  View details for DOI 10.3171/2021.9.PEDS2185

  View details for PubMedID 34861643

• Neuro-Ophthalmologic Monitoring in the Management of Increased Intracranial Pressure From Leaking Arachnoid Cysts JOURNAL OF NEURO-OPHTHALMOLOGY Deveney, T. K., Lebas, M., Lobo, R. R., Maher, C. O., Trobe, J. D. 2021; 41 (4): E535-E540

  Abstract

  Intracranial arachnoid cysts are common incidental imaging findings. They may rarely rupture, leading to the development of subdural hygromas and high intracranial pressure (ICP). Neurosurgical intervention has been advocated in the past, but recent evidence indicates that most cases resolve spontaneously. The role of neuro-ophthalmologic monitoring in identifying the few cases that have persisting vision-threatening papilledema that justifies intervention has not been emphasized.Retrospective review of 4 cases of leaking arachnoid cysts drawn from the files of the University of Michigan Medical Center (Michigan Medicine) between 2007 and 2018.In 1 case, surgery was avoidable as papilledema resolved over time despite lingering imaging features of mass effect. In 3 cases, papilledema persisted with the threat of permanent vision loss, prompting neurosurgical intervention. In one of those cases, the fluid collection was thinly but extensively spread across both hemispheres without brain shift; yet, papilledema was pronounced. Emergent evacuation led to rapid resolution of papilledema and encephalopathy, but with residual optic nerve damage.Because constitutional symptoms and even imaging are not always reliable indicators of high ICP in leaking arachnoid cysts, neuro-ophthalmologic monitoring of papilledema is valuable in identifying the cases when neurosurgical intervention is necessary.

  View details for DOI 10.1097/WNO.0000000000001143

  View details for Web of Science ID 000744840900029

  View details for PubMedID 33734153

• Longitudinal scoliosis behavior in Chiari malformation with and without syringomyelia JOURNAL OF NEUROSURGERY-PEDIATRICS Chotai, S., Nadel, J. L., Holste, K. G., Mossner, J. M., Smith, B. W., Kapurch, J. R., Muraszko, K. M., Garton, H. L., Maher, C. O., Strahle, J. M. 2021; 28 (5): 585-591

  Abstract

  The objective of this study was to understand the natural history of scoliosis in patients with Chiari malformation type I (CM-I) with and without syringomyelia.A retrospective review of data was conducted. Patients with CM-I were identified from a cohort of 14,118 individuals age 18 years or younger who had undergone MRI over an 11-year period at the University of Michigan. Patients eligible for study inclusion had a coronal curve ≥ 10° on radiography, associated CM-I with or without syringomyelia, and at least 1 year of clinical follow-up prior to any surgery. Curve magnitude at initial diagnosis, prior to posterior fossa decompression (PFD; if applicable), and at the last follow-up (prior to any surgical correction of scoliosis) was recorded, and clinical and radiographic characteristics were noted. The change in curve magnitude by 10° was defined as curve progression (increase by 10°) or regression (decrease by 10°).Forty-three patients met the study inclusion criteria and were analyzed. About one-third (35%) of the patients presented with symptoms attributed to their CM-I. The mean degree of scoliosis at presentation was 32.6° ± 17.7°. Twenty-one patients (49%) had an associated syrinx. The mean tonsil position below the level of the foramen magnum was 9.8 ± 5.8 mm. Patients with a syrinx were more likely to have a curve > 20° (86% vs 41%, p = 0.002). Curve magnitude remained stable (≤ ±10°) in 77% of patients (33/43), progressed in 16% (7/43), and regressed in 7% (3/43). Mean age was higher (14.8 ± 0.59 years) among patients with regressed curves (p = 0.026). All regressed curves initially measured ≤ 20° (mean 14° ± 5.3°), and none of the patients with regressed curves had a syrinx. The change in curve magnitude was statistically similar in patients with (7.32° ± 17.7°) and without (5.32° ± 15.8°) a syrinx (p = 0.67). After a mean follow-up of 3.13 ± 2.04 years prior to surgery, 27 patients (63%) ultimately underwent posterior fossa or scoliosis correction surgery. For those who eventually underwent PFD only, the rate of change in curve magnitude prior to surgery was 0.054° ± 0.79°. The rate of change in curve magnitude was statistically similar before (0.054° ± 0.79°) and after (0.042° ± 0.33°) surgery (p = 0.45) for patients who underwent PFD surgery only.The natural history of scoliosis in the presence of CM-I is variable, though most curves remained stable. All curves that regressed were ≤ 20° at initial diagnosis, and most patients in such cases were older at scoliosis diagnosis. Patients who underwent no surgery or PFD only had similar profiles for the change in curve magnitude, which remained relatively stable overall, as compared to patients who underwent PFD and subsequent fusion, who demonstrated curve progression. Among the patients with a syrinx, no curves regressed, most remained stable, and some progressed. Understanding this variability is a first step toward building a prediction model for outcomes for these patients.

  View details for DOI 10.3171/2021.5.PEDS20915

  View details for Web of Science ID 000729256000002

  View details for PubMedID 34479199

• Incidental Intracranial Cysts in Children PEDIATRIC CLINICS OF NORTH AMERICA Muhlestein, W. E., Maher, C. O. 2021; 68 (4): 775-782

  Abstract

  With increasing use of intracranial imaging, the diagnosis of benign intracranial cysts is becoming more frequent in the pediatric population. These lesions are usually incidentally discovered during the work-up of unrelated symptoms. Most do not require treatment and many do not even require imaging follow-up. When symptomatic, symptoms of these lesions are usually caused by local mass effect. Symptomatic lesions warrant neurosurgical evaluation, and may require surgical intervention in rare, well-selected cases. This article describes three common benign intracranial cysts found in the pediatric population: arachnoid cysts, choroid cysts, and pineal cysts.

  View details for DOI 10.1016/j.pcl.2021.04.005

  View details for Web of Science ID 000674696400008

  View details for PubMedID 34247708

• Complications and outcomes of posterior fossa decompression with duraplasty versus without duraplasty for pediatric patients with Chiari malformation type I and syringomyelia: a study from the Park-Reeves Syringomyelia Research Consortium JOURNAL OF NEUROSURGERY-PEDIATRICS Akbari, S. A., Yahanda, A. T., Ackerman, L. L., Adelson, P., Ahmed, R., Albert, G. W., Aldana, P. R., Alden, T. D., Anderson, R. E., Bauer, D. F., Bethel-Anderson, T., Bierbrauer, K., Brockmeyer, D. L., Chern, J. J., Couture, D. E., Daniels, D. J., Dlouhy, B. J., Durham, S. R., Ellenbogen, R. G., Eskandari, R., Fuchs, H. E., Grant, G. A., Graupman, P. C., Greene, S., Greenfield, J. P., Gross, N. L., Guillaume, D. J., Hankinson, T. C., Heuer, G. G., Iantosca, M., Iskandar, B. J., Jackson, E. M., Jallo, G., Johnston, J. M., Kaufman, B. A., Keating, R. F., Khan, N. R., Krieger, M. D., Leonard, J. R., Maher, C. O., Mangano, F. T., McComb, J., McEvoy, S. D., Meehan, T., Menezes, A. H., Muhlbauer, M. S., O'Neill, B. R., Olavarria, G., Ragheb, J., Selden, N. R., Shah, M. N., Shannon, C. N., Shimony, J. S., Smyth, M. D., Stone, S. D., Strahle, J. M., Tamber, M. S., Torner, J. C., Tuite, G. F., Tyler-Kabara, E. C., Wait, S. D., Wellons, J. C., Whitehead, W. E., Park, T., Limbrick, D. D. 2021; 30 (1): 39-51

  Abstract

  The aim of this study was to determine differences in complications and outcomes between posterior fossa decompression with duraplasty (PFDD) and without duraplasty (PFD) for the treatment of pediatric Chiari malformation type I (CM1) and syringomyelia (SM).The authors used retrospective and prospective components of the Park-Reeves Syringomyelia Research Consortium database to identify pediatric patients with CM1-SM who received PFD or PFDD and had at least 1 year of follow-up data. Preoperative, treatment, and postoperative characteristics were recorded and compared between groups.A total of 692 patients met the inclusion criteria for this database study. PFD was performed in 117 (16.9%) and PFDD in 575 (83.1%) patients. The mean age at surgery was 9.86 years, and the mean follow-up time was 2.73 years. There were no significant differences in presenting signs or symptoms between groups, although the preoperative syrinx size was smaller in the PFD group. The PFD group had a shorter mean operating room time (p < 0.0001), fewer patients with > 50 mL of blood loss (p = 0.04), and shorter hospital stays (p = 0.0001). There were 4 intraoperative complications, all within the PFDD group (0.7%, p > 0.99). Patients undergoing PFDD had a 6-month complication rate of 24.3%, compared with 13.7% in the PFD group (p = 0.01). There were no differences between groups for postoperative complications beyond 6 months (p = 0.33). PFD patients were more likely to require revision surgery (17.9% vs 8.3%, p = 0.002). PFDD was associated with greater improvements in headaches (89.6% vs 80.8%, p = 0.04) and back pain (86.5% vs 59.1%, p = 0.01). There were no differences between groups for improvement in neurological examination findings. PFDD was associated with greater reduction in anteroposterior syrinx size (43.7% vs 26.9%, p = 0.0001) and syrinx length (18.9% vs 5.6%, p = 0.04) compared with PFD.PFD was associated with reduced operative time and blood loss, shorter hospital stays, and fewer postoperative complications within 6 months. However, PFDD was associated with better symptom improvement and reduction in syrinx size and lower rates of revision decompression. The two surgeries have low intraoperative complication rates and comparable complication rates beyond 6 months.

  View details for DOI 10.3171/2022.2.PEDS21446

  View details for Web of Science ID 000843455600005

  View details for PubMedID 35426814

• Author reply to letter to the editor regarding "Seizure Prophylaxis in Unruptured Aneurysm Repair: A Randomized Controlled Trial" JOURNAL OF STROKE & CEREBROVASCULAR DISEASES Daou, B. J., Maher, C. O., Thompson, B., Pandey, A. S. 2021; 30 (7): 105722

  View details for DOI 10.1016/j.jstrokecerebrovasdis.2021.105722

  View details for Web of Science ID 000660018300002

  View details for PubMedID 33712370

• Extradural decompression versus duraplasty in Chiari malformation type I with syrinx: outcomes on scoliosis from the Park-Reeves Syringomyelia Research Consortium. Journal of neurosurgery. Pediatrics Sadler, B., Skidmore, A., Gewirtz, J., Anderson, R. C., Haller, G., Ackerman, L. L., Adelson, P. D., Ahmed, R., Albert, G. W., Aldana, P. R., Alden, T. D., Averill, C., Baird, L. C., Bauer, D. F., Bethel-Anderson, T., Bierbrauer, K. S., Bonfield, C. M., Brockmeyer, D. L., Chern, J. J., Couture, D. E., Daniels, D. J., Dlouhy, B. J., Durham, S. R., Ellenbogen, R. G., Eskandari, R., Fuchs, H. E., George, T. M., Grant, G. A., Graupman, P. C., Greene, S., Greenfield, J. P., Gross, N. L., Guillaume, D. J., Hankinson, T. C., Heuer, G. G., Iantosca, M., Iskandar, B. J., Jackson, E. M., Jea, A. H., Johnston, J. M., Keating, R. F., Khan, N., Krieger, M. D., Leonard, J. R., Maher, C. O., Mangano, F. T., Mapstone, T. B., McComb, J. G., McEvoy, S. D., Meehan, T., Menezes, A. H., Muhlbauer, M., Oakes, W. J., Olavarria, G., O'Neill, B. R., Ragheb, J., Selden, N. R., Shah, M. N., Shannon, C. N., Smith, J., Smyth, M. D., Stone, S. S., Tuite, G. F., Wait, S. D., Wellons, J. C., Whitehead, W. E., Park, T. S., Limbrick, D. D., Strahle, J. M. 2021: 1-9

  Abstract

  OBJECTIVE: Scoliosis is common in patients with Chiari malformation type I (CM-I)-associated syringomyelia. While it is known that treatment with posterior fossa decompression (PFD) may reduce the progression of scoliosis, it is unknown if decompression with duraplasty is superior to extradural decompression.METHODS: A large multicenter retrospective and prospective registry of 1257 pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for patients with scoliosis who underwent PFD with or without duraplasty.RESULTS: In total, 422 patients who underwent PFD had a clinical diagnosis of scoliosis. Of these patients, 346 underwent duraplasty, 51 received extradural decompression alone, and 25 were excluded because no data were available on the type of PFD. The mean clinical follow-up was 2.6 years. Overall, there was no difference in subsequent occurrence of fusion or proportion of patients with curve progression between those with and those without a duraplasty. However, after controlling for age, sex, preoperative curve magnitude, syrinx length, syrinx width, and holocord syrinx, extradural decompression was associated with curve progression > 10°, but not increased occurrence of fusion. Older age at PFD and larger preoperative curve magnitude were independently associated with subsequent occurrence of fusion. Greater syrinx reduction after PFD of either type was associated with decreased occurrence of fusion.CONCLUSIONS: In patients with CM-I, syrinx, and scoliosis undergoing PFD, there was no difference in subsequent occurrence of surgical correction of scoliosis between those receiving a duraplasty and those with an extradural decompression. However, after controlling for preoperative factors including age, syrinx characteristics, and curve magnitude, patients treated with duraplasty were less likely to have curve progression than patients treated with extradural decompression. Further study is needed to evaluate the role of duraplasty in curve stabilization after PFD.

  View details for DOI 10.3171/2020.12.PEDS20552

  View details for PubMedID 34144521

• Weighing In on the Controversy: Preoperative Imaging in Unicoronal Craniosynostosis Leads to Strategic Changes in Surgical Care PLASTIC AND RECONSTRUCTIVE SURGERY Ulma, R. M., Ranganathan, K. L., Vercler, C. J., Garton, H. L., Maher, C. O., Muraszko, K. M., Buchman, S. R. 2021; 147 (5): 1133-1139

  Abstract

  Clinical findings in children with unilateral coronal craniosynostosis are characteristic, and therefore clinicians have questioned the need for confirmatory imaging. Preoperative computed tomographic imaging is a powerful tool for diagnosing associated anomalies that can alter treatment management and surgical planning. The authors' aim was to determine whether and how routine preoperative imaging affected treatment management in unilateral coronal craniosynostosis patients within their institution.A retrospective, single-center review of all patients who underwent cranial vault remodeling for unilateral coronal craniosynostosis between 2006 and 2014 was performed. Patient data included demographics, age at computed tomographic scan, age at surgery, results of the radiographic evaluation, and modification of treatment following radiologic examination.Of 194 patients diagnosed with single-suture craniosynostosis, 29 were diagnosed with unilateral coronal craniosynostosis. Additional radiographic anomalies were found in 19 unilateral coronal craniosynostosis patients (65.5 percent). These included severe deviation of the anterior superior sagittal sinus [n = 12 (41.4 percent)], Chiari I malformation [n = 1 (3.4 percent)], and benign external hydrocephalus [n = 2 (6.9 percent)]. The radiographic anomalies resulted in a change in management for 48.3 percent of patients. Specifically, alteration in frontal craniotomy design occurred in 12 patients (41.4 percent), and two patients (6.9 percent) required further radiographic studies.Although clinical findings in children with unilateral coronal craniosynostosis are prototypical, preoperative computed tomographic imaging is still of great consequence and continues to play an important role in surgical management. Preoperative imaging enabled surgeons to alter surgical management and avoid inadvertent complications such as damage to a deviated superior sagittal sinus. Imaging findings of Chiari malformation and hydrocephalus also permitted judicious follow-up.Therapeutic, IV.

  View details for DOI 10.1097/PRS.0000000000007830

  View details for Web of Science ID 000644992000073

  View details for PubMedID 33890895

• Dural augmentation approaches and complication rates after posterior fossa decompression for Chiari I malformation and syringomyelia: a Park-Reeves Syringomyelia Research Consortium study JOURNAL OF NEUROSURGERY-PEDIATRICS Yahanda, A. T., Adelson, P., Akbari, S. A., Albert, G. W., Aldana, P. R., Alden, T. D., Anderson, R. E., Bauer, D. F., Bethel-Anderson, T., Brockmeyer, D. L., Chern, J. J., Couture, D. E., Daniels, D. J., Dlouhy, B. J., Durham, S. R., Ellenbogen, R. G., Eskandari, R., George, T. M., Grant, G. A., Graupman, P. C., Greene, S., Greenfield, J. P., Gross, N. L., Guillaume, D. J., Hankinson, T. C., Heuer, G. G., Iantosca, M., Iskandar, B. J., Jackson, E. M., Johnston, J. M., Keating, R. F., Krieger, M. D., Leonard, J. R., Maher, C. O., Mangano, F. T., McComb, J., McEvoy, S. D., Meehan, T., Menezes, A. H., O'Neill, B. R., Olavarria, G., Ragheb, J., Selden, N. R., Shah, M. N., Shannon, C. N., Shimony, J. S., Smyth, M. D., Stone, S. D., Strahle, J. M., Torner, J. C., Tuite, G. F., Wait, S. D., Wellons, J. C., Whitehead, W. E., Park, T., Limbrick, D. D. 2021; 27 (4): 459-468

  Abstract

  Posterior fossa decompression with duraplasty (PFDD) is commonly performed for Chiari I malformation (CM-I) with syringomyelia (SM). However, complication rates associated with various dural graft types are not well established. The objective of this study was to elucidate complication rates within 6 months of surgery among autograft and commonly used nonautologous grafts for pediatric patients who underwent PFDD for CM-I/SM.The Park-Reeves Syringomyelia Research Consortium database was queried for pediatric patients who had undergone PFDD for CM-I with SM. All patients had tonsillar ectopia ≥ 5 mm, syrinx diameter ≥ 3 mm, and ≥ 6 months of postoperative follow-up after PFDD. Complications (e.g., pseudomeningocele, CSF leak, meningitis, and hydrocephalus) and postoperative changes in syrinx size, headaches, and neck pain were compared for autograft versus nonautologous graft.A total of 781 PFDD cases were analyzed (359 autograft, 422 nonautologous graft). Nonautologous grafts included bovine pericardium (n = 63), bovine collagen (n = 225), synthetic (n = 99), and human cadaveric allograft (n = 35). Autograft (103/359, 28.7%) had a similar overall complication rate compared to nonautologous graft (143/422, 33.9%) (p = 0.12). However, nonautologous graft was associated with significantly higher rates of pseudomeningocele (p = 0.04) and meningitis (p < 0.001). The higher rate of meningitis was influenced particularly by the higher rate of chemical meningitis (p = 0.002) versus infectious meningitis (p = 0.132). Among 4 types of nonautologous grafts, there were differences in complication rates (p = 0.02), including chemical meningitis (p = 0.01) and postoperative nausea/vomiting (p = 0.03). Allograft demonstrated the lowest complication rates overall (14.3%) and yielded significantly fewer complications compared to bovine collagen (p = 0.02) and synthetic (p = 0.003) grafts. Synthetic graft yielded higher complication rates than autograft (p = 0.01). Autograft and nonautologous graft resulted in equal improvements in syrinx size (p < 0.0001). No differences were found for postoperative changes in headaches or neck pain.In the largest multicenter cohort to date, complication rates for dural autograft and nonautologous graft are similar after PFDD for CM-I/SM, although nonautologous graft results in higher rates of pseudomeningocele and meningitis. Rates of meningitis differ among nonautologous graft types. Autograft and nonautologous graft are equivalent for reducing syrinx size, headaches, and neck pain.

  View details for DOI 10.3171/2020.8.PEDS2087

  View details for Web of Science ID 000636738500002

  View details for PubMedID 33578390

• Radiation-Induced Imaging Changes and Cerebral Edema following Stereotactic Radiosurgery for Brain AVMs. AJNR. American journal of neuroradiology Daou, B. J., Palmateer, G., Wilkinson, D. A., Thompson, B. G., Maher, C. O., Chaudhary, N., Gemmete, J. J., Hayman, J. A., Lam, K., Wahl, D. R., Kim, M., Pandey, A. S. 2021; 42 (1): 82-87

  Abstract

  T2 signal and FLAIR changes in patients undergoing stereotactic radiosurgery for brain AVMs may occur posttreatment and could result in adverse radiation effects. We aimed to evaluate outcomes in patients with these imaging changes, the frequency and degree of this response, and factors associated with it.Through this retrospective cohort study, consecutive patients treated with stereotactic radiosurgery for brain AVMs who had at least 1 year of follow-up MR imaging were identified. Logistic regression analysis was used to evaluate predictors of outcomes.One-hundred-sixty AVMs were treated in 148 patients (mean, 35.6 years of age), including 42 (26.2%) pediatric AVMs. The mean MR imaging follow-up was 56.5 months. The median Spetzler-Martin grade was III. The mean maximal AVM diameter was 2.8 cm, and the mean AVM target volume was 7.4 mL. The median radiation dose was 16.5 Gy. New T2 signal and FLAIR hyperintensity were noted in 40% of AVMs. T2 FLAIR volumes at 3, 6, 12, 18, and 24 months were, respectively, 4.04, 55.47, 56.42, 48.06, and 29.38 mL Radiation-induced neurologic symptoms were encountered in 34.4%. In patients with radiation-induced imaging changes, 69.2% had new neurologic symptoms versus 9.5% of patients with no imaging changes (P = .0001). Imaging changes were significantly associated with new neurologic findings (P < .001). Larger AVM maximal diameter (P = .04) and the presence of multiple feeding arteries (P = .01) were associated with radiation-induced imaging changes.Radiation-induced imaging changes are common following linear particle accelerator-based stereotactic radiosurgery for brain AVMs, appear to peak at 12 months, and are significantly associated with new neurologic findings.

  View details for DOI 10.3174/ajnr.A6880

  View details for PubMedID 33214183

  View details for PubMedCentralID PMC7814808

• Pediatric Arteriovenous Malformations Youman and Winn's Neurological Surgery Maher , C., Wilkinson , A. Elsevier. 2021; 8th
• Occipital-Cervical Fusion and Ventral Decompression in the Surgical Management of Chiari-1 Malformation and Syringomyelia: Analysis of Data From the Park-Reeves Syringomyelia Research Consortium. Neurosurgery CreveCoeur, T. S., Yahanda, A. T., Maher, C. O., Johnson, G. W., Ackerman, L. L., Adelson, P. D., Ahmed, R., Albert, G. W., Aldana, P. R., Alden, T. D., Anderson, R. C., Baird, L., Bauer, D. F., Bierbrauer, K. S., Brockmeyer, D. L., Chern, J. J., Couture, D. E., Daniels, D. J., Dauser, R. C., Durham, S. R., Ellenbogen, R. G., Eskandari, R., Fuchs, H. E., George, T. M., Grant, G. A., Graupman, P. C., Greene, S., Greenfield, J. P., Gross, N. L., Guillaume, D. J., Haller, G., Hankinson, T. C., Heuer, G. G., Iantosca, M., Iskandar, B. J., Jackson, E. M., Jea, A. H., Johnston, J. M., Keating, R. F., Kelly, M. P., Khan, N., Krieger, M. D., Leonard, J. R., Mangano, F. T., Mapstone, T. B., McComb, J. G., Menezes, A. H., Muhlbauer, M., Oakes, W. J., Olavarria, G., O'Neill, B. R., Park, T. S., Ragheb, J., Selden, N. R., Shah, M. N., Shannon, C., Shimony, J. S., Smith, J., Smyth, M. D., Stone, S. S., Strahle, J. M., Tamber, M. S., Torner, J. C., Tuite, G. F., Wait, S. D., Wellons, J. C., Whitehead, W. E., Limbrick, D. D. 2020

  Abstract

  BACKGROUND: Occipital-cervical fusion (OCF) and ventral decompression (VD) may be used in the treatment of pediatric Chiari-1 malformation (CM-1) with syringomyelia (SM) as adjuncts to posterior fossa decompression (PFD) for complex craniovertebral junction pathology.OBJECTIVE: To examine factors influencing the use of OCF and OCF/VD in a multicenter cohort of pediatric CM-1 and SM subjects treated with PFD.METHODS: The Park-Reeves Syringomyelia Research Consortium registry was used to examine 637 subjects with cerebellar tonsillar ectopia≥5mm, syrinx diameter≥3mm, and at least 1 yr of follow-up after their index PFD. Comparisons were made between subjects who received PFD alone and those with PFD+OCF or PFD+OCF/VD.RESULTS: All 637 patients underwent PFD, 505 (79.2%) with and 132 (20.8%) without duraplasty. A total of 12 subjects went on to have OCF at some point in their management (PFD+OCF), whereas 4 had OCF and VD (PFD+OCF/VD). Of those with complete data, a history of platybasia (3/10, P=.011), Klippel-Feil (2/10, P=.015), and basilar invagination (3/12, P<.001) were increased within the OCF group, whereas only basilar invagination (1/4, P<.001) was increased in the OCF/VD group. Clivo-axial angle (CXA) was significantly lower for both OCF (128.8± 15.3°, P=.008) and OCF/VD (115.0± 11.6°, P=.025) groups when compared to PFD-only group (145.3± 12.7°). pB-C2 did not differ among groups.CONCLUSION: Although PFD alone is adequate for treating the vast majority of CM-1/SM patients, OCF or OCF/VD may be occasionally utilized. Cranial base and spine pathologies and CXA may provide insight into the need for OCF and/or OCF/VD.

  View details for DOI 10.1093/neuros/nyaa460

  View details for PubMedID 33313928

• ELECTRONIC SEQUENCING PROVIDES OPTIMIZED QUANTIFICATION OF SERIAL, MULTI-GENE MOLECULAR RESPONSE IN THE CSF OF CHILDREN WITH HIGH-GRADE GLIOMA Bruzek, A., Muruganand, A., Ravi, K., Wadden, J., Babila, C., Tunkle, L., Wierzbicki, K., Stallard, S., Cantor, E., Qin, T., Wolfe, I., Mody, R., Muraszko, K., Franson, A., Robertson, P., Maher, C., Garton, H., Koschmann, C. OXFORD UNIV PRESS INC. 2020: 288

  View details for Web of Science ID 000606080100060

• Electronic DNA Analysis of CSF Cell-free Tumor DNA to Quantify Multi-gene Molecular Response in Pediatric High-grade Glioma CLINICAL CANCER RESEARCH Bruzek, A. K., Ravi, K., Muruganand, A., Wadden, J., Babila, C., Cantor, E., Tunkle, L., Wierzbicki, K., Stallard, S., Dickson, R. P., Wolfe, I., Mody, R., Schwartz, J., Franson, A., Robertson, P. L., Muraszko, K. M., Maher, C. O., Garton, H. L., Qin, T., Koschmann, C. 2020; 26 (23): 6266-6276

  Abstract

  Pediatric high-grade glioma (pHGG) diagnosis portends poor prognosis and therapeutic monitoring remains difficult. Tumors release cell-free tumor DNA (cf-tDNA) into cerebrospinal fluid (CSF), allowing for potential detection of tumor-associated mutations by CSF sampling. We hypothesized that direct, electronic analysis of cf-tDNA with a handheld platform (Oxford Nanopore MinION) could quantify patient-specific CSF cf-tDNA variant allele fraction (VAF) with improved speed and limit of detection compared with established methods.We performed ultra-short fragment (100-200 bp) PCR amplification of cf-tDNA for clinically actionable alterations in CSF and tumor samples from patients with pHGG (n = 12) alongside nontumor CSF (n = 6). PCR products underwent rapid amplicon-based sequencing by Oxford Nanopore Technology (Nanopore) with quantification of VAF. Additional comparison to next-generation sequencing (NGS) and droplet digital PCR (ddPCR) was performed.Nanopore demonstrated 85% sensitivity and 100% specificity in CSF samples (n = 127 replicates) with 0.1 femtomole DNA limit of detection and 12-hour results, all of which compared favorably with NGS. Multiplexed analysis provided concurrent analysis of H3.3A (H3F3A) and H3C2 (HIST1H3B) mutations in a nonbiopsied patient and results were confirmed by ddPCR. Serial CSF cf-tDNA sequencing by Nanopore demonstrated correlation of radiological response on a clinical trial, with one patient showing dramatic multi-gene molecular response that predicted long-term clinical response.Nanopore sequencing of ultra-short pHGG CSF cf-tDNA fragments is feasible, efficient, and sensitive with low-input samples thus overcoming many of the barriers restricting wider use of CSF cf-tDNA diagnosis and monitoring in this patient population.

  View details for DOI 10.1158/1078-0432.CCR-20-2066

  View details for Web of Science ID 000595599500021

  View details for PubMedID 33087334

  View details for PubMedCentralID PMC7710567

• Normal cerebral ventricular volume growth in childhood JOURNAL OF NEUROSURGERY-PEDIATRICS Cutler, N. S., Srinivasan, S., Aaron, B. L., Anand, S., Kang, M. S., Altshuler, D. B., Schermerhorn, T. C., Hollon, T. C., Maher, C. O., Khalsa, S. S. 2020; 26 (5): 517-524

  Abstract

  Normal percentile growth charts for head circumference, length, and weight are well-established tools for clinicians to detect abnormal growth patterns. Currently, no standard exists for evaluating normal size or growth of cerebral ventricular volume. The current standard practice relies on clinical experience for a subjective assessment of cerebral ventricular size to determine whether a patient is outside the normal volume range. An improved definition of normal ventricular volumes would facilitate a more data-driven diagnostic process. The authors sought to develop a growth curve of cerebral ventricular volumes using a large number of normal pediatric brain MR images.The authors performed a retrospective analysis of patients aged 0 to 18 years, who were evaluated at their institution between 2009 and 2016 with brain MRI performed for headaches, convulsions, or head injury. Patients were excluded for diagnoses of hydrocephalus, congenital brain malformations, intracranial hemorrhage, meningitis, or intracranial mass lesions established at any time during a 3- to 10-year follow-up. The volume of the cerebral ventricles for each T2-weighted MRI sequence was calculated with a custom semiautomated segmentation program written in MATLAB. Normal percentile curves were calculated using the lambda-mu-sigma smoothing method.Ventricular volume was calculated for 687 normal brain MR images obtained in 617 different patients. A chart with standardized growth curves was developed from this set of normal ventricular volumes representing the 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles. The charted data were binned by age at scan date by 3-month intervals for ages 0-1 year, 6-month intervals for ages 1-3 years, and 12-month intervals for ages 3-18 years. Additional percentile values were calculated for boys only and girls only.The authors developed centile estimation growth charts of normal 3D ventricular volumes measured on brain MRI for pediatric patients. These charts may serve as a quantitative clinical reference to help discern normal variance from pathologic ventriculomegaly.

  View details for DOI 10.3171/2020.5.PEDS20178

  View details for Web of Science ID 000583057700008

  View details for PubMedID 32823266

• Seizure Prophylaxis in Unruptured Aneurysm Repair: A Randomized Controlled Trial JOURNAL OF STROKE & CEREBROVASCULAR DISEASES Daou, B. J., Maher, C. O., Holste, K., Palmateer, G., Lint, C., Elenbaas, J., Thompson, B., Pandey, A. S. 2020; 29 (10): 105171

  Abstract

  Prophylactic antiepileptic drugs (pAEDs) are often prescribed for seizure prophylaxis in patients undergoing surgical treatment of unruptured intracranial aneurysms (UIAs). We aimed to evaluate the benefit of pAEDs in patients undergoing surgical repair of UIAs.We randomly assigned eligible patients undergoing surgical repair of UIAs to receive levetiracetam for seven days post-operatively or standard care alone. The primary outcome was the evaluation of seizures in the perioperative period (within 4 weeks). We also evaluated seizure occurrence throughout follow-up and assessed functional outcomes using the modified Rankin scale score (mRS).35 patients were randomized to the "no-levetiracetam" group and 41 patients were randomized to receive levetiracetam. The two study groups had similar overall baseline characteristics and the surgical complication rate was similar for both groups (p = 0.8). One patient in the "no-levetiracetam" group had a seizure in the perioperative period versus 2 patients in the group randomized to receive levetiracetam (2.9% vs 4.9%, respectively, p = 1.00). No patients in the "no-levetiracetam" group had any additional late seizures (mean follow-up of 20.4 months), but three patients in the levetiracetam group had late seizures during follow-up (mean follow-up of 19.1 months) (0% vs 7.3%, p = 0.2). mRS score of 0-2 at 90 days and at the latest follow-up were similar between the two groups (p = 1.00).Perioperative seizure prophylaxis with levetiracetam does not reduce the rate of seizures as compared to controls in patients undergoing surgical repair of UIAs.

  View details for DOI 10.1016/j.jstrokecerebrovasdis.2020.105171

  View details for Web of Science ID 000569086800015

  View details for PubMedID 32912546

• Stereotactic Radiosurgery for Brain Arteriovenous Malformations: Evaluation of Obliteration and Review of Associated Predictors JOURNAL OF STROKE & CEREBROVASCULAR DISEASES Daou, B. J., Palmateer, G., Thompson, B., Maher, C. O., Hayman, J. A., Lam, K. L., Wahl, D. R., Kim, M., Pandey, A. S. 2020; 29 (8): 104863

  Abstract

  High arteriovenous malformation (AVM) obliteration rates have been reported with stereotactic radiosurgery (SRS), and multiple factors have been found to be associated with AVM obliteration. These predictors have been inconsistent throughout studies. We aimed to analyze our experience with linear accelerator (LINAC)-based SRS for brain AVMs, evaluate outcomes, assess factors associated with AVM obliteration and review the various reported predictors of AVM obliteration.Electronic medical records were retrospectively reviewed to identify consecutive patients with brain AVMs treated with SRS over a 27-year period with at least 2 years of follow-up. Logistic regression analysis was performed to identify factors associated with AVM obliteration.One hundred twenty-eight patients with 142 brain AVMs treated with SRS were included. Mean age was 34.4 years. Fifty-two percent of AVMs were associated with a hemorrhage before SRS, and 14.8% were previously embolized. Mean clinical and angiographic follow-up times were 67.8 months and 58.6 months, respectively. The median Spetzler-Martin grade was 3. Mean maximal AVM diameter was 2.8 cm and mean AVM target volume was 7.4 cm3 with a median radiation dose of 16 Gy. Complete AVM obliteration was achieved in 80.3%. Radiation-related signs and symptoms were encountered in 32.4%, only 4.9% of which consisted of a permanent deficit. Post-SRS AVM-related hemorrhage occurred in 6.3% of cases. In multivariate analysis, factors associated with AVM obliteration included younger patient age (P = .019), male gender (P = .008), smaller AVM diameter (P = .04), smaller AVM target volume (P = .009), smaller isodose surface volume (P = .005), a higher delivered radiation dose (P = .013), and having only one major draining vein (P = .04).AVM obliteration with LINAC-based radiosurgery was safe and effective and achieved complete AVM obliteration in about 80% of cases. The most prominent predictors of AVM success included AVM size, AVM volume, radiation dose, number of draining veins and patient age.

  View details for DOI 10.1016/j.jstrokecerebrovasdis.2020.104863

  View details for Web of Science ID 000561808800007

  View details for PubMedID 32689634

• Pediatric neurosurgery along with children's hospitals' innovations are rapid and uniform in response to the COVID-19 pandemic JOURNAL OF NEUROSURGERY-PEDIATRICS Weiner, H. L., Adelson, P., Brockmeyer, D. L., Maher, C. O., Gupta, N., Smyth, M. D., Jea, A., Blount, J. P., Riva-Cambrin, J., Lam, S. K., Ahn, E. S., Albert, G. W., Leonard, J. R. 2020; 26 (1): 3-5

  View details for DOI 10.3171/2020.4.PEDS20240

  View details for Web of Science ID 000577166500002

  View details for PubMedID 32302988

  View details for PubMedCentralID PMC7164397

• Obstetric Management and Maternal Outcomes of Childbirth Among Patients With Chiari Malformation Type I NEUROSURGERY Wilkinson, D., Johnson, K., Castaneda, P. R., Nadel, J. L., Garton, H. L., Muraszko, K. M., Maher, C. O. 2020; 87 (1): 45-52

  Abstract

  A range of opinions exist in the literature regarding obstetric management of pregnant women with Chiari malformation type I (CM-I).To examine obstetrical practices and outcomes with childbirth of women with CM-I.We examined insurance claims data from a large, privately insured health care network and identified admissions for childbirth from 2004 to 2014. Women with a diagnosis of CM-I as well as normal controls were analyzed for demographic characteristics, type of obstetric management, and complications of childbirth.We identified 866 patients with CM-I diagnosis who had 1048 hospitalizations for delivery, including 103 deliveries to 83 patients who underwent performance of CM-I decompression (CMD) either before or after childbirth. Among 400 births that occurred after CM-I diagnosis, rates of caesarean section (C-section) were higher (42.3% vs 36.2%, OR 1.29, 95% CI 1.00-1.66, P = .05) and rates of epidural analgesia were lower (45.3% vs 55.4%, OR 0.67, 95% CI 0.52-0.85, P = .001) compared to 648 births before CM-I diagnosis. The rate of serious maternal morbidity was similar among deliveries to women with CM-I diagnosis (both before and after delivery) compared to 11 000 normal controls.A diagnosis of CM-I prior to delivery is associated with a higher rate of C-section and a lower rate of epidural analgesia. Rates of serious maternal morbidity among women with CM-I were similar to those for normal controls. The data suggest a predelivery diagnosis of CM-I may influence obstetric decisions despite no evidence of substantially increased delivery risk in this group.

  View details for DOI 10.1093/neuros/nyz341

  View details for Web of Science ID 000546254300013

  View details for PubMedID 31504826

• Using a Mobile Application for Evaluation of Procedural Learning in Neurosurgery WORLD NEUROSURGERY Koduri, S., Altshuler, D. B., Khalsa, S. S., Maher, C. O., Wnuk, G., Tong, D., George, B. C., Szerlip, N. 2020; 138: E124-E150

  Abstract

  Feedback is a major component of any educational process. Competency assessment and feedback are essential tools for teaching surgical skills. Most current systems of assessment within neurosurgical residency programs use evaluations aggregated over a period of time, which lead to significant bias, rather than case-specific feedback. We describe the use of a mobile device application called SIMPL (System for Improving and Measuring Procedural Learning) to allow for immediate surgical competency assessment and improve the quality of feedback after every operative experience.We retrospectively assessed our use of this program and neurosurgery residents' response to the program. Institutional review board approval was not required, and no patients were involved in the study. This application has already been implemented within general surgery programs with promising results. We document its implementation in a neurosurgery program and the output of the program for residents and program directors.This is the first documentation of such an application within a neurosurgical residency program. In a 6-month period at a single institution, around 300 evaluations were completed by residents and faculty, with a >80% response rate within both groups. Furthermore, these evaluations were companied by a 60% dictation rate from faculty, which contains verbal feedback that is available to residents for playback at any time.The telephone-based SIMPL application allows for assessment of surgical competency and remains quick and easy to use, giving it the potential to improve individual neurosurgical training experiences across the United States.

  View details for DOI 10.1016/J.WNEU.2020.02.049

  View details for Web of Science ID 000540728900015

  View details for PubMedID 32081831

• Factors associated with syrinx size in pediatric patients treated for Chiari malformation type I and syringomyelia: a study from the Park-Reeves Syringomyelia Research Consortium JOURNAL OF NEUROSURGERY-PEDIATRICS Hale, A. T., Adelson, P., Albert, G. W., Aldana, P. R., Alden, T. D., Anderson, R. E., Bauer, D. F., Bonfield, C. M., Brockmeyer, D. L., Chern, J. J., Couture, D. E., Daniels, D. J., Durham, S. R., Ellenbogen, R. G., Eskandari, R., George, T. M., Grant, G. A., Graupman, P. C., Greene, S., Greenfield, J. P., Gross, N. L., Guillaume, D. J., Heuer, G. G., Iantosca, M., Iskandar, B. J., Jackson, E. M., Johnston, J. M., Keating, R. F., Leonard, J. R., Maher, C. O., Mangano, F. T., McComb, J., Meehan, T., Menezes, A. H., O'Neill, B., Olavarria, G., Park, T., Ragheb, J., Selden, N. R., Shah, M. N., Smyth, M. D., Stone, S. D., Strahle, J. M., Wait, S. D., Wellons, J. C., Whitehead, W. E., Shannon, C. N., Limbrick, D. D., Pk Reeves Syringomyelia Res Co 2020; 25 (6): 629-639

  Abstract

  Factors associated with syrinx size in pediatric patients undergoing posterior fossa decompression (PFD) or PFD with duraplasty (PFDD) for Chiari malformation type I (CM-I) with syringomyelia (SM; CM-I+SM) are not well established.Using the Park-Reeves Syringomyelia Research Consortium registry, the authors analyzed variables associated with syrinx radiological outcomes in patients (< 20 years old at the time of surgery) with CM-I+SM undergoing PFD or PFDD. Syrinx resolution was defined as an anteroposterior (AP) diameter of ≤ 2 mm or ≤ 3 mm or a reduction in AP diameter of ≥ 50%. Syrinx regression or progression was defined using 1) change in syrinx AP diameter (≥ 1 mm), or 2) change in syrinx length (craniocaudal, ≥ 1 vertebral level). Syrinx stability was defined as a < 1-mm change in syrinx AP diameter and no change in syrinx length.The authors identified 380 patients with CM-I+SM who underwent PFD or PFDD. Cox proportional hazards modeling revealed younger age at surgery and PFDD as being independently associated with syrinx resolution, defined as a ≤ 2-mm or ≤ 3-mm AP diameter or ≥ 50% reduction in AP diameter. Radiological syrinx resolution was associated with improvement in headache (p < 0.005) and neck pain (p < 0.011) after PFD or PFDD. Next, PFDD (p = 0.005), scoliosis (p = 0.007), and syrinx location across multiple spinal segments (p = 0.001) were associated with syrinx diameter regression, whereas increased preoperative frontal-occipital horn ratio (FOHR; p = 0.007) and syrinx location spanning multiple spinal segments (p = 0.04) were associated with syrinx length regression. Scoliosis (HR 0.38 [95% CI 0.16-0.91], p = 0.03) and smaller syrinx diameter (5.82 ± 3.38 vs 7.86 ± 3.05 mm; HR 0.60 [95% CI 0.34-1.03], p = 0.002) were associated with syrinx diameter stability, whereas shorter preoperative syrinx length (5.75 ± 4.01 vs 9.65 ± 4.31 levels; HR 0.21 [95% CI 0.12-0.38], p = 0.0001) and smaller pB-C2 distance (6.86 ± 1.27 vs 7.18 ± 1.38 mm; HR 1.44 [95% CI 1.02-2.05], p = 0.04) were associated with syrinx length stability. Finally, younger age at surgery (8.19 ± 5.02 vs 10.29 ± 4.25 years; HR 1.89 [95% CI 1.31-3.04], p = 0.01) was associated with syrinx diameter progression, whereas increased postoperative syrinx diameter (6.73 ± 3.64 vs 3.97 ± 3.07 mm; HR 3.10 [95% CI 1.67-5.76], p = 0.003), was associated with syrinx length progression. PFD versus PFDD was not associated with syrinx progression or reoperation rate.These data suggest that PFDD and age are independently associated with radiological syrinx improvement, although forthcoming results from the PFDD versus PFD randomized controlled trial (NCT02669836, clinicaltrials.gov) will best answer this question.

  View details for DOI 10.3171/2020.1.PEDS19493

  View details for Web of Science ID 000595648500001

  View details for PubMedID 32114543

• Thirty-Day Hospital Readmission and Surgical Complication Rates for Shunting in Normal Pressure Hydrocephalus: A Large National Database Analysis NEUROSURGERY Nadel, J. L., Wilkinson, D., Linzey, J. R., Maher, C. O., Kotagal, V., Heth, J. A. 2020; 86 (6): 843-850

  Abstract

  Research on age-related complications secondary to shunts in normal pressure hydrocephalus (NPH) is primarily limited to single-center studies and small cohorts.To determine the rates of hospital readmission and surgical complications, and factors that predict them, following shunt surgery for NPH in a large healthcare network.Surgical procedures, complications, and readmissions for adults undergoing ventricular shunting for NPH were determined using de-identified claims from a privately insured United States healthcare network in years 2007-2014. Univariate and multivariate statistics were used to determine factors that predict poor surgical outcomes. The primary outcome variable was surgical complications or readmissions (composite variable for any major perioperative complication or 30-d readmission).The 30-d readmission rate for 974 patients with NPH who underwent ventricular shunting was 7.29%; the most common reasons for readmission were shunt-related complications, infection, hemorrhage, altered mental status, and cardiopulmonary and musculoskeletal problems. The perioperative complication rate was 21.15%, including intraparenchymal hemorrhage (5.85%) and extra-axial (subdural or epidural) hematoma (5.54%). The overall rate of having a surgical complication or 30-d readmission was 25.15%. Age did not predict surgical complication or 30-d readmission. Preoperative comorbidities independently associated with poor outcome were myocardial infarction within 1 yr (OR = 3.984, 95% CI = 1.105-14.368); existing cerebrovascular disease (odds ratio [OR] = 2.206, 95% CI = 1.544-3.152); and moderate/severe renal disease (OR = 2.000, 95% CI = 1.155-3.464).The rate of complications or readmission within 30 d of ventricular shunting for NPH is 25.15%. Preoperative comorbidities of myocardial infarction within 1 yr, cerebrovascular disease, and moderate/severe renal disease are independent risk factors for poor outcome.

  View details for DOI 10.1093/neuros/nyz299

  View details for Web of Science ID 000538792600046

  View details for PubMedID 31420654

  View details for PubMedCentralID PMC7528659

• In Reply: Obstetric Management and Maternal Outcomes of Childbirth Among Patients With Chiari Malformation Type I NEUROSURGERY Maher, C. O. 2020; 86 (5): E474

  View details for DOI 10.1093/neuros/nyz561

  View details for Web of Science ID 000537429900014

  View details for PubMedID 31885039

• Syringomyelia in children with closed spinal dysraphism: long-term outcomes after surgical intervention JOURNAL OF NEUROSURGERY-PEDIATRICS Bruzek, A. K., Starr, J., Garton, H. L., Muraszko, K. M., Maher, C. O., Strahle, J. M. 2020; 25 (3): 319-325

  Abstract

  The nature of the relationship between spinal cord syrinx and tethered cord is not well known. It is unclear if surgical cord untethering results in resolution or improvement of an associated syrinx. The objective of this study was to report the response of spinal cord syrinx to surgical cord untethering.The authors retrospectively reviewed all patients with a syrinx and tethered cord who presented to a single institution over an 11-year interval. Patients with open neural tube defects were excluded. Thirty-one patients were identified, 25 of whom had both clinical and imaging follow-up after surgery. Patients were grouped according to etiology of the tethered cord. Clinical outcomes and syrinx characteristics were recorded.Of the 25 patients with tethered cord, 68% (n = 17) were male. The average age at presentation was 2.5 years (0-10.1 years) and age at surgery was 3.7 years (range 1 day to 17 years). Etiologies of tethered cord were lipomyelomeningocele (n = 8), thickened/fatty filum (n = 7), intradural lipoma (n = 5), myelocystocele (n = 2), meningocele (n = 2), and diastematomyelia (n = 1). Twenty-three of the patients underwent primary untethering, whereas 2 patients had received untethering previously at another institution. The average syrinx length and width prior to surgery were 4.81 vertebral levels (SD 4.35) and 5.19 mm (SD 2.55 mm), respectively. Conus level ranged from L1 to S3. Patients were followed for an average of 8.4 years (1.35-15.85 years). Overall there was no significant change in syrinx length or width postoperatively; the average syrinx length increased by 0.86 vertebral levels (SD 4.36) and width decreased by 0.72 mm (SD 2.94 mm). Seven of 25 patients had improvement in at least one presenting symptom, including scoliosis, weakness, bowel/bladder dysfunction, and pain. Eight patients had stable presenting symptoms. Six patients were asymptomatic and 5 patients had new or worsening symptoms, which included scoliosis, pain, or sensory changes.Although some syrinxes improved after surgery for tethered cord, radiological improvement was not consistent and did not appear to be associated with change in clinical symptoms. The decision to surgically untether a cord should be focused on the clinical symptoms and not the presence of a syrinx alone. Further studies are needed to confirm this finding.

  View details for DOI 10.3171/2019.9.PEDS1944

  View details for Web of Science ID 000518390100016

  View details for PubMedID 31835253

• Predictors of surgical treatment in children with tethered fibrofatty filum terminale JOURNAL OF NEUROSURGERY-PEDIATRICS Kashlan, O. N., Wilkinson, D., Morgenstern, H., Khalsa, S. S., Maher, C. O. 2020; 25 (2): 196-203

  Abstract

  Thickened or fatty filum terminale is an occult lesion that can cause tethered cord syndrome requiring surgical untethering. This study's objectives were to estimate the incidence of tethered fibrofatty filum terminale (TFFT) in a large insured pediatric population, identify predictors of surgery among those TFFT patients, and assess a diagnostic algorithm.TFFT was defined according to the ICD-9-CM code for cord tethering (742.59), after excluding codes for diastematomyelia, lipomyelomeningocele, terminal myelocystocele, meningocele, and myelomeningocele. Utilizing the Optum Insight database for 2001-2014, the authors identified pediatric patients (< 21 years) in the US who were diagnosed with a tethered cord and estimated the TFFT incidence rates in that source population and the surgical untethering probability among TFFT patients over the 14-year period. Logistic regression was used to estimate the effects (adjusted OR and 95% CI) of age at diagnosis, sex, Charlson Comorbidity Index (CCI) score, diagnosis of Chiari malformation type I, diagnosis of syrinx, and the probability of surgery by US census region. Lastly, to evaluate their algorithm for identifying TFFT from ICD-9 codes, the authors estimated its positive predictive value (PPV) among 50 children who were diagnosed at their institution and met the ICD-9-CM criteria.There were 3218 diagnoses of TFFT, with 482 of these pediatric patients undergoing tethered cord release during the study period. The estimated incidence rate was 12.0 per 100,000/year (95% CI 11.6-12.4 per 100,000/year). The incidence rate was slightly higher in females than in males (12.7 vs 11.4 per 100,000/year). The probability of surgery in the total pediatric TFFT population was 15.0% (95% CI 13.8%-16.2%) and was greater in children with a syrinx (OR 2.2, 95% CI 1.6-3.0), children 7-11 years of age at diagnosis versus < 1 year (OR 1.5, 95% CI 1.1-2.0), CCI score ≥ 3 versus 0 (OR 2.3, 95% CI 1.4-3.8), and residents of the Western vs Northeastern US (OR 2.3, 95% CI 1.6-3.5). In the authors' own institution's database, the PPV of TFFT was 35/50 (70.0%, 95% CI 57.3%-82.7%) for identifying tethered cord due to fibrofatty filum terminale among childhood positives.Patients with comorbidities or an associated syrinx showed a higher risk of untethering procedures for TFFT. Also, surgery was appreciably more frequent in the Western US. These findings signify the need for a collaborative prospective cohort study of long-term outcomes for TFFT patients with and without surgery to determine which patients should have surgery.

  View details for DOI 10.3171/2019.8.PEDS19292

  View details for Web of Science ID 000511109700014

  View details for PubMedID 31675690

• Near real-time intraoperative brain tumor diagnosis using stimulated Raman histology and deep neural networks NATURE MEDICINE Hollon, T. C., Pandian, B., Adapa, A. R., Urias, E., Save, A. V., Khalsa, S. S., Eichberg, D. G., D'Amico, R. S., Farooq, Z. U., Lewis, S., Petridis, P. D., Marie, T., Shah, A. H., Garton, H. L., Maher, C. O., Heth, J. A., McKean, E. L., Sullivan, S. E., Hervey-Jumper, S. L., Patil, P. G., Thompson, B., Sagher, O., McKhann, G. M., Komotar, R. J., Ivan, M. E., Snuderl, M., Otten, M. L., Johnson, T. D., Sisti, M. B., Bruce, J. N., Muraszko, K. M., Trautman, J., Freudiger, C. W., Canoll, P., Lee, H., Camelo-Piragua, S., Orringer, D. A. 2020; 26 (1): 52-+

  Abstract

  Intraoperative diagnosis is essential for providing safe and effective care during cancer surgery1. The existing workflow for intraoperative diagnosis based on hematoxylin and eosin staining of processed tissue is time, resource and labor intensive2,3. Moreover, interpretation of intraoperative histologic images is dependent on a contracting, unevenly distributed, pathology workforce4. In the present study, we report a parallel workflow that combines stimulated Raman histology (SRH)5-7, a label-free optical imaging method and deep convolutional neural networks (CNNs) to predict diagnosis at the bedside in near real-time in an automated fashion. Specifically, our CNNs, trained on over 2.5 million SRH images, predict brain tumor diagnosis in the operating room in under 150 s, an order of magnitude faster than conventional techniques (for example, 20-30 min)2. In a multicenter, prospective clinical trial (n = 278), we demonstrated that CNN-based diagnosis of SRH images was noninferior to pathologist-based interpretation of conventional histologic images (overall accuracy, 94.6% versus 93.9%). Our CNNs learned a hierarchy of recognizable histologic feature representations to classify the major histopathologic classes of brain tumors. In addition, we implemented a semantic segmentation method to identify tumor-infiltrated diagnostic regions within SRH images. These results demonstrate how intraoperative cancer diagnosis can be streamlined, creating a complementary pathway for tissue diagnosis that is independent of a traditional pathology laboratory.

  View details for DOI 10.1038/s41591-019-0715-9

  View details for Web of Science ID 000509831900026

  View details for PubMedID 31907460

  View details for PubMedCentralID PMC6960329

• Natural History of Chiari Malformations The Chiari Malformations Tubbs , R., Turgot , M., Oakes , W. 2020; 2nd
• Pediatric neurosurgery training during residency in the United States: a program director survey. Journal of neurosurgery. Pediatrics Limoges, N. n., D'Agostino, E. n., Gelinne, A. n., Maher, C. O., Scott, R. M., Grant, G. n., Krieger, M. D., Limbrick, D. D., White, M. n., Durham, S. n. 2020: 1–7

  Abstract

  Pediatric neurosurgery is a core component of neurosurgical residency training. Pediatric case minimums are established by the Neurosurgery Residency Review Committee of the Accreditation Council for Graduate Medical Education (ACGME). Case minimums, by themselves, allow for great variability in training between programs. There are no prior data on how the residency programs meet these requirements. The authors' objective was to gather information on pediatric neurosurgical education among the ACGME-accredited neurosurgery training programs in order to shape further pediatric neurosurgical educational efforts.A 25-question survey about pediatric neurosurgical education was created by the Education Committee of the Section on Pediatric Neurological Surgery of the American Association of Neurological Surgeons/Congress of Neurological Surgeons and distributed to program directors of all 111 ACGME-accredited neurosurgery training programs.The response rate was 77% (86/111). In 55% of programs the residents are rotated to a responder-designated "freestanding" children's hospital, and 39% of programs rotate residents to a children's hospital within a larger adult hospital or a general hospital. There are 4 or fewer pediatric neurosurgical faculty in 91% of programs. In 12% of programs less than 100 cases are performed per year, and in 45% more than 500 are performed. In 31% of responding neurosurgery residency programs there is also a pediatric neurosurgery fellowship program supported by the same sponsoring institution. Seventy-seven percent of programs have at least one specific pediatric neurosurgery rotation, with 71% of those rotations occurring during postgraduate year 3 and 50% occurring during postgraduate year 4. The duration of pediatric rotation varies from no specific rotation to more than 1 year, with 48% of residents spending 4-6 months on a pediatric rotation and 12% spending 7-11 months. Last, 17% of programs send their residents to external sites sponsoring other residency programs for their pediatric rotation.There is great variety between neurosurgery training programs with regard to resident education in pediatric neurosurgery. This study's data will serve as a baseline for future studies, and the authors hope the findings will guide further efforts in pediatric neurosurgical education in residency training programs.

  View details for DOI 10.3171/2020.1.PEDS19662

  View details for PubMedID 32197250

• Development of Common Data Elements for Use in Chiari Malformation Type I Clinical Research: An NIH/NINDS Project NEUROSURGERY Luciano, M. G., Batzdorf, U., Kula, R. W., Rocque, B. G., Maher, C. O., Heiss, J., Martin, B. A., Bolognese, P. A., Ashley-Koch, A., Limbrick, D., Poppe, D. J., Esposito, K. M., Odenkirchen, J., Esterlitz, J. R., Ala'i, S., Joseph, K., Feldman, R. S., Riddle, R., Chiari I Malformation Common Data 2019; 85 (6): 854-859

  Abstract

  The management of Chiari I malformation (CMI) is controversial because treatment methods vary and treatment decisions rest on incomplete understanding of its complex symptom patterns, etiologies, and natural history. Validity of studies that attempt to compare treatment of CMI has been limited because of variable terminology and methods used to describe study subjects. The goal of this project was to standardize terminology and methods by developing a comprehensive set of Common Data Elements (CDEs), data definitions, case report forms (CRFs), and outcome measure recommendations for use in CMI clinical research, as part of the CDE project at the National Institute of Neurological Disorders and Stroke (NINDS) of the US National Institutes of Health. A working group, comprising over 30 experts, developed and identified CDEs, template CRFs, data dictionaries, and guidelines to aid investigators starting and conducting CMI clinical research studies. The recommendations were compiled, internally reviewed, and posted online for external public comment. In October 2016, version 1.0 of the CMI CDE recommendations became available on the NINDS CDE website. The recommendations span these domains: Core Demographics/Epidemiology; Presentation/Symptoms; Co-Morbidities/Genetics; Imaging; Treatment; and Outcome. Widespread use of CDEs could facilitate CMI clinical research trial design, data sharing, retrospective analyses, and consistent data sharing between CMI investigators around the world. Updating of CDEs will be necessary to keep them relevant and applicable to evolving research goals for understanding CMI and its treatment.

  View details for DOI 10.1093/neuros/nyy475

  View details for Web of Science ID 000501737300015

  View details for PubMedID 30690581

  View details for PubMedCentralID PMC7054710

• Arachnoid cyst prevalence JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O. 2019; 24 (6): 736-737

  View details for DOI 10.3171/2019.6.PEDS19334

  View details for Web of Science ID 000500271300019

  View details for PubMedID 31629318

• USE OF A NOVEL, HAND-HELD, ELECTRONIC DNA ANALYSIS PLATFORM TO QUANTIFY MULTI-GENE MOLECULAR RESPONSE IN CSF OF PATIENTS WITH HIGH-GRADE GLIOMA Bruzek, A., Tunkle, L., Babila, C., Muruganand, A., Stallard, S., Thamilselvan, V., Qin, T., Wolfe, I., Mody, R., Robertson, P., Maher, C., Muraszko, K., Garton, H., Koschmann, C. OXFORD UNIV PRESS INC. 2019: 188-189

  View details for Web of Science ID 000509478704091

• Intraoperative Phase Contrast MRI Analysis of Cerebrospinal Fluid Velocities During Posterior Fossa Decompression for Chiari I Malformation JOURNAL OF MAGNETIC RESONANCE IMAGING Delavari, N., Wang, A. C., Bapuraj, J., Londy, F., Muraszko, K. M., Garton, H. L., Maher, C. O. 2020; 51 (5): 1463-1470

  Abstract

  Cerebrospinal fluid (CSF) velocity at the craniovertebral junction (CVJ) is known to be altered in patients with Chiari I malformation (CMI), and normalization of CSF velocities is associated with symptom resolution. However, preoperative and intraoperative prediction methods have thus far failed to identify patients in whom CSF velocities can be normalized with posterior fossa decompression (PFD) without duraplasty. Phase contrast MRI (PC-MRI) may assist not only in diagnosis of CMI but also in guiding the intraoperative decision to perform duraplasty during PFD.To use intraoperative MRI data to quantify changes in CSF hydrodynamics at the CVJ during each step of PFD with duraplasty (PFDD) in 12 consecutive patients.Retrospective case series with all patients imaged before, during and after decompression, and all data analyzed postprocedure.Pediatric patients, mean age 14 years (range 4-18), undergoing PFD for CMI.Intraoperative studies involved a dedicated 1.5T Siemens MRI imager. PC-MRI scans were in the axial plane at the CVJ.Two observers assessed measurements.The equality of matched pairs of observations was tested using the Wilcoxon matched-pairs signed-ranks test.Data analyses of the PC-MRI demonstrated a marked and immediate increase in CSF velocity at the posterior CVJ during PFDD. Mean cranially-directed velocities increased by a mean of 1.049cm/s (P = 0.028) from preincision to postoperative measurement. There was a mean 0.45 cm/s (P = 0.022) increase in mean cranial velocity from preincision to bone decompression scans, and a mean 0.48 cm/s (P = 0.018) increase in mean velocity from preincision to duraplasty.In all subjects, significant increases in the mean and peak velocities of cranially- and caudally-directed velocities were observed from preincision to post-PFDD scans at the posterior CVJ.2 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2020;51:1463-1470.

  View details for DOI 10.1002/jmri.26953

  View details for Web of Science ID 000493297200001

  View details for PubMedID 31667928

• Morphometric changes at the craniocervical junction during childhood JOURNAL OF NEUROSURGERY-PEDIATRICS Bapuraj, J., Bruzek, A. K., Tarpeh, J. K., Pelissier, L., Garton, H. L., Anderson, R. E., Nan, B., Ma, T., Maher, C. O. 2019; 24 (3): 227-235

  Abstract

  Current understanding of how the pediatric craniocervical junction develops remains incomplete. Measurements of anatomical relationships at the craniocervical junction can influence clinical and surgical decision-making. The purpose of this analysis was to quantitatively define clinically relevant craniocervical junction measurements in a population of children with CT scans that show normal anatomy.A total of 1458 eligible patients were identified from children between 1 and 18 years of age who underwent cervical spine CT scanning at a single institution. Patients were separated by both sex and age in years into 34 groups. Following this, patients within each group were randomly selected for inclusion until a target of 15 patients in each group had been reached. Each patient underwent measurement of the occipital condyle-C1 interval (CCI), pB-C2, atlantodental interval (ADI), basion-dens interval (BDI), basion-opisthion diameter (BOD), basion-axial interval (BAI), dens angulation, and canal diameter at C1. Mean values were calculated in each group. Each measurement was performed by two teams and compared for intraclass correlation coefficient (ICC).The data showed that CCI, ADI, BDI, and dens angulation decrease in magnitude throughout childhood, while pB-C2, PADI, BAI, and BOD increase throughout childhood, with an ICC of fair to good (range 0.413-0.912). Notably, CCI decreases continuously on coronal CT scans, whereas on parasagittal CT scans, CCI does not decrease until after age 9, when it shows a continuous decline similar to measurements on coronal CT scans.These morphometric analyses establish parameters for normal pediatric craniocervical spine growth for each year of life up to 18 years. The data should be considered when evaluating children for potential surgical intervention.

  View details for DOI 10.3171/2019.4.PEDS1968

  View details for Web of Science ID 000484053700002

  View details for PubMedID 31226679

• Postgraduate publishing output in pediatric neurosurgery: correlation with fellowship site and individual scholars JOURNAL OF NEUROSURGERY-PEDIATRICS Ajmera, S., Lee, R. P., Schultz, A., Hersh, D. S., Lepard, J., Xu, R., Saad, H., Akinduro, O., Justo, M., Fraser, B. D., Motiwala, M., Dave, P., Jimenez, B., Wallace, D. A., Osikoya, O., Norrdahl, S., Dooley, J. H., Khan, N. R., Vaughn, B. N., Maher, C. O., Klimo, P. 2019; 24 (3): 343-351

  Abstract

  The objective of this study was to analyze the publication output of postgraduate pediatric neurosurgery fellows for a 10-year period as well as identify 25 individual highly productive pediatric neurosurgeons. The correlation between academic productivity and the site of fellowship training was studied.Programs certified by the Accreditation Council for Pediatric Neurosurgery Fellowships that had 5 or more graduating fellows from 2006 to 2015 were included for analysis. Fellows were queried using Scopus for publications during those 10 years with citation data through 2017. Pearson correlation coefficients were calculated, comparing program rankings of faculty against fellows using the revised Hirsch index (r-index; primary) and Hirsch index (h-index; secondary). A list of 25 highly accomplished individual academicians and their fellowship training locations was compiled.Sixteen programs qualified with 152 fellows from 2006 to 2015; 136 of these surgeons published a total of 2009 articles with 23,735 citations. Most publications were pediatric-specific (66.7%) clinical articles (93.1%), with middle authorship (55%). Co-investigators were more likely from residency than fellowship. There was a clustering of the top 7 programs each having total publications of around 120 or greater, publications per fellow greater than 12, more than 1200 citations, and adjusted ir10 (revised 10-year institutional h-index) and ih10 (10-year institutional h-index) values of approximately 2 or higher. Correlating faculty and fellowship program rankings yielded correlation coefficients ranging from 0.53 to 0.80. Fifteen individuals (60%) in the top 25 (by r5 index) list completed their fellowship at 1 of these 7 institutions.Approximately 90% of fellowship-trained pediatric neurosurgeons have 1 or more publications, but the spectrum of output is broad. There is a strong correlation between where surgeons complete their fellowships and postgraduate publications.

  View details for DOI 10.3171/2019.4.PEDS18717

  View details for Web of Science ID 000484053700014

  View details for PubMedID 31226678

• Radiological and clinical predictors of scoliosis in patients with Chiari malformation type I and spinal cord syrinx from the Park-Reeves Syringomyelia Research Consortium. Journal of neurosurgery. Pediatrics Strahle, J. M., Taiwo, R., Averill, C., Torner, J., Shannon, C. N., Bonfield, C. M., Tuite, G. F., Bethel-Anderson, T., Rutlin, J., Brockmeyer, D. L., Wellons, J. C., Leonard, J. R., Mangano, F. T., Johnston, J. M., Shah, M. N., Iskandar, B. J., Tyler-Kabara, E. C., Daniels, D. J., Jackson, E. M., Grant, G. A., Couture, D. E., Adelson, P. D., Alden, T. D., Aldana, P. R., Anderson, R. C., Selden, N. R., Baird, L. C., Bierbrauer, K., Chern, J. J., Whitehead, W. E., Ellenbogen, R. G., Fuchs, H. E., Guillaume, D. J., Hankinson, T. C., Iantosca, M. R., Oakes, W. J., Keating, R. F., Khan, N. R., Muhlbauer, M. S., McComb, J. G., Menezes, A. H., Ragheb, J., Smith, J. L., Maher, C. O., Greene, S., Kelly, M., O'Neill, B. R., Krieger, M. D., Tamber, M., Durham, S. R., Olavarria, G., Stone, S. S., Kaufman, B. A., Heuer, G. G., Bauer, D. F., Albert, G., Greenfield, J. P., Wait, S. D., Van Poppel, M. D., Eskandari, R., Mapstone, T., Shimony, J. S., Dacey, R. G., Smyth, M. D., Park, T. S., Limbrick, D. D. 2019: 1–8

  Abstract

  OBJECTIVE: Scoliosis is frequently a presenting sign of Chiari malformation type I (CM-I) with syrinx. The authors' goal was to define scoliosis in this population and describe how radiological characteristics of CM-I and syrinx relate to the presence and severity of scoliosis.METHODS: A large multicenter retrospective and prospective registry of pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for clinical and radiological characteristics of CM-I, syrinx, and scoliosis (coronal curve ≥ 10°).RESULTS: Based on available imaging of patients with CM-I and syrinx, 260 of 825 patients (31%) had a clear diagnosis of scoliosis based on radiographs or coronal MRI. Forty-nine patients (5.9%) did not have scoliosis, and in 516 (63%) patients, a clear determination of the presence or absence of scoliosis could not be made. Comparison of patients with and those without a definite scoliosis diagnosis indicated that scoliosis was associated with wider syrinxes (8.7 vs 6.3 mm, OR 1.25, p < 0.001), longer syrinxes (10.3 vs 6.2 levels, OR 1.18, p < 0.001), syrinxes with their rostral extent located in the cervical spine (94% vs 80%, OR 3.91, p = 0.001), and holocord syrinxes (50% vs 16%, OR 5.61, p < 0.001). Multivariable regression analysis revealed syrinx length and the presence of holocord syrinx to be independent predictors of scoliosis in this patient cohort. Scoliosis was not associated with sex, age at CM-I diagnosis, tonsil position, pB-C2 distance (measured perpendicular distance from the ventral dura to a line drawn from the basion to the posterior-inferior aspect of C2), clivoaxial angle, or frontal-occipital horn ratio. Average curve magnitude was 29.9°, and 37.7% of patients had a left thoracic curve. Older age at CM-I or syrinx diagnosis (p < 0.0001) was associated with greater curve magnitude whereas there was no association between syrinx dimensions and curve magnitude.CONCLUSIONS: Syrinx characteristics, but not tonsil position, were related to the presence of scoliosis in patients with CM-I, and there was an independent association of syrinx length and holocord syrinx with scoliosis. Further study is needed to evaluate the nature of the relationship between syrinx and scoliosis in patients with CM-I.

  View details for DOI 10.3171/2019.5.PEDS18527

  View details for PubMedID 31419800

• A Large Database Analysis of Rates of Aneurysm Screening, Elective Treatment, and Subarachnoid Hemorrhage in Patients With Polycystic Kidney Disease NEUROSURGERY Wilkinson, D., Burke, J. F., Nadel, J. L., Maher, C. O., Chaudhary, N., Gemmete, J. J., Heung, M., Thompson, B., Pandey, A. S. 2019; 85 (2): E266-E274

  Abstract

  Professional societies provide conflicting guidelines on aneurysm screening in patients with polycystic kidney disease (PKD), and the rate of subarachnoid hemorrhage (SAH) is poorly understood.To evaluate screening, elective treatment, and the rate of SAH in patients with known PKD.We examined longitudinally linked claims data from a large private insurer, identifying screening, elective treatment, aneurysmal subarachnoid hemorrhage (aSAH) and secured aneurysmal SAH (saSAH) in 2004 to 2014 amongst patients with known PKD.We identified 20 704 patients diagnosed with PKD. Among patients with an initial PKD diagnosis, 51/446 (15.9%) underwent angiographic screening within 2 yr. Forty aneurysms were treated electively in 48 868 yr at risk in PKD patients (82/100K patient yr, 95% confidence interval [CI] 60-112) vs 24 elective treatments in 349 861 yr at risk in age- and sex-matched controls (7/100K patient yr, 95% CI 5-10, P < .0001). Eleven admissions for aSAH were identified in PKD patients (23/100K patient yr, 95% CI 13-41) and 22 admissions for aSAH in controls (6/100K patient yr, 95% CI 4-10), giving an incidence rate ratio (IRR) of 3.6 (95% CI 1.7-7.4, P < .0001) and a comorbidity-adjusted IRR of 3.1 (95% CI 1.4-6.9). The incidence of saSAH was proportionally even higher in PKD patients than controls, 16 vs 2/100K patient years, IRR 9.5 (95% CI 3.3-27.5, P < .0001).Screening in PKD is performed only selectively, though resulting rates of elective treatment were over 10× those of controls. Despite screening and treatment, the rate of SAH remains significantly elevated over that of controls.

  View details for DOI 10.1093/neuros/nyy551

  View details for Web of Science ID 000493103500034

  View details for PubMedID 30476226

• Development of bilateral dural arteriovenous fistulae following pial synangiosis for moyamoya syndrome: case report JOURNAL OF NEUROSURGERY-PEDIATRICS Koduri, S., Wilkinson, D., Griauzde, J. M., Gemmete, J. J., Maher, C. O. 2019; 24 (1): 9-13

  Abstract

  Moyamoya syndrome predisposes patients to ischemic or hemorrhagic stroke due to progressive narrowing of intracranial vessels with subsequent small-vessel collateralization. Dural arteriovenous fistulae (DAVFs) are most commonly noted after venous sinus or cortical vein thrombosis and are believed to be primarily due to venous hypertension and elevated sinus pressures, although there is no known association with moyamoya syndrome, or with surgical treatment for moyamoya disease (MMD). The authors present the case of a 14-year-old girl with Down syndrome treated using pial synangiosis for MMD who subsequently was noted to have bilateral DAVFs. This case provides a new perspective on the origins and underlying pathophysiology of both moyamoya syndrome and DAVFs, and also serves to highlight the importance of monitoring the moyamoya population closely for de novo cerebrovascular changes after revascularization procedures.

  View details for DOI 10.3171/2019.2.PEDS18603

  View details for Web of Science ID 000473331600002

  View details for PubMedID 30978680

• RAPID, ULTRA-DEEP SEQUENCING OF PEDIATRIC DIPG FROM CEREBROSPINAL FLUID USING A NOVEL HAND-HELD ELECTRONIC DNA ANALYSIS PLATFORM Bruzek, A. K., Tunkle, L., Stallard, S., Thamilselvan, V., Qin, T., Wolfe, I., Mody, R., Muraszko, K. L., Robertson, P. L., Maher, C. O., Garton, H. L., Koschmann, C. OXFORD UNIV PRESS INC. 2019: 69

  View details for DOI 10.1093/neuonc/noz036.027

  View details for Web of Science ID 000473243700028

• Recent trends in North American pediatric neurosurgical fellowship training JOURNAL OF NEUROSURGERY-PEDIATRICS Nadel, J. L., Scott, R., Durham, S. R., Maher, C. O. 2019; 23 (4): 517-522

  Abstract

  OBJECTIVE The goal of this study was to evaluate trends in pediatric neurosurgical fellowship training in North America. METHODS From a database maintained by the Accreditation Council for Pediatric Neurosurgery Fellowships (ACPNF), all graduates of ACPNF-accredited pediatric neurosurgery fellowships were identified, and an Internet search was conducted to determine sex, undergraduate and graduate degrees, location and dates of residency and fellowship training, current practice/employment environment, American Board of Neurological Surgery (ABNS) or Fellowship of the Royal College of Surgeons certification status, American Board of Pediatric Neurological Surgery (ABPNS) certification status, and extent of current pediatric-focused practice. The graduates were further studied to determine whether they had completed a neurosurgical residency at a program with an affiliated ACPNF-accredited pediatric neurosurgery fellowship program, and their residency training programs were further classified by whether the program was ranked in the top 50 by NIH funding awards. Each fellowship graduate’s current practice was also ranked in a similar fashion. RESULTS There were 391 graduates of ACPNF-accredited pediatric neurosurgery fellowship programs from 1993 to 2018. The number of graduates per year has grown steadily over time, as has the percentage of women, now over 40% compared to zero in the first 3 years of fellowship accreditation in the mid-1990s. Approximately 71% of graduating fellows have a pediatric-focused practice, but only 63% went on to attain ABPNS certification. Of all graduates practicing in the United States, 68% practice in academic settings. Ninety-five percent of graduating fellows who were ABNS board eligible were ABNS certified. CONCLUSIONS A study of the graduates of accredited pediatric neurosurgical fellowships from 1993 to 2018 has revealed a growth in the number of graduates from ACPNF-accredited fellowship programs over time. A substantial portion of graduates will practice at least some adult neurosurgery and not go on to obtain ABPNS board certification.

  View details for DOI 10.3171/2018.10.PEDS18106

  View details for Web of Science ID 000462877000016

  View details for PubMedID 30611157

• Screening and surgery for foramen magnum stenosis in children with achondroplasia: a large, national database analysis JOURNAL OF NEUROSURGERY-PEDIATRICS Nadel, J. L., Wilkinson, D., Garton, H. L., Muraszko, K. M., Maher, C. O. 2019; 23 (3): 374-380

  Abstract

  OBJECTIVE The goal of this study was to determine the rates of screening and surgery for foramen magnum stenosis in children with achondroplasia in a large, privately insured healthcare network. METHODS Rates of screening and surgery for foramen magnum stenosis in children with achondroplasia were determined using de-identified insurance claims data from a large, privately insured healthcare network of over 58 million beneficiaries across the United States between 2001 and 2014. Cases of achondroplasia and screening and surgery claims were identified using a combination of International Classification of Diseases diagnosis codes and Current Procedural Terminology codes. American Academy of Pediatrics (AAP) practice guidelines were used to determine screening trends. RESULTS The search yielded 3577 children age 19 years or younger with achondroplasia. Of them, 236 met criteria for inclusion in the screening analysis. Among the screening cohort, 41.9% received some form of screening for foramen magnum stenosis, whereas 13.9% of patients were fully and appropriately screened according to the 2005 guidelines from the AAP. The screening rate significantly increased after the issuance of the AAP guidelines. Among all children in the cohort, 25 underwent cervicomedullary decompression for foramen magnum stenosis. The incidence rate of undergoing cervicomedullary decompression was highest in infancy (28 per 1000 patient-years) and decreased with age (5 per 1000 patient-years for all other ages combined). CONCLUSIONS Children with achondroplasia continue to be underscreened for foramen magnum stenosis, although screening rates have improved since the release of the 2005 AAP surveillance guidelines. The incidence of surgery was highest in infants and decreased with age.

  View details for DOI 10.3171/2018.9.PEDS18410

  View details for Web of Science ID 000461144200017

  View details for PubMedID 30554178

• The Preventable Shunt Revision Rate: A Multicenter Evaluation NEUROSURGERY Dave, P., Venable, G. T., Jones, T. L., Khan, N. R., Albert, G. W., Chern, J. J., Wheelus, J. L., Governale, L. S., Huntoon, K. M., Maher, C. O., Bruzek, A. K., Mangano, F. T., Mehta, V., Beaudoin, W., Naftel, R. P., Basem, J., Whitney, A., Shimony, N., Rodriguez, L. F., Vaughn, B. N., Klimo, P. 2019; 84 (3): 788-797

  Abstract

  The Preventable Shunt Revision Rate (PSRR) was recently introduced as a novel quality metric.To evaluate the PSRR across multiple centers and determine associated variables.Nine participating centers in North America provided at least 2 years of consecutive shunt operations. Index surgery was defined as new shunt implantation, or revision of an existing shunt. For any index surgery that resulted in a reoperation within 90-days, index surgery information (demographic, clinical, and procedural) was collected and a decision made whether the failure was potentially preventable. The 90-day shunt failure rate and PSRR were calculated per institution and combined. Bivariate analyses were performed to evaluate individual effects of each independent variable on preventable shunt failure followed by a final multivariable model using a backward model selection approach.A total of 5092 shunt operations were performed; 861 failed within 90 days of index operation, resulting in a 16.9% combined 90-day shunt failure rate and 17.6% median failure rate (range, 8.7%-26.9%). Of the failures, 307 were potentially preventable (overall and median 90-day PSRR, 35.7% and 33.9%, respectively; range, 16.1%-55.4%). The most common etiologies of avoidable failure were infection (n = 134, 44%) and proximal catheter malposition (n = 83, 27%). Independent predictors of preventable failure (P < .05) were lack of endoscopy (odds ratio [OR] = 2.26), recent shunt infection (OR = 3.65), shunt type (OR = 2.06) and center.PSRR is variable across institutions, but can be 50% or higher. While the PSRR may never reach zero, this study demonstrates that overall about a third of early failures are potentially preventable.

  View details for DOI 10.1093/neuros/nyy263

  View details for Web of Science ID 000460636600075

  View details for PubMedID 29982642

• Development of best practices to minimize wound complications after complex tethered spinal cord surgery: a modified Delphi study JOURNAL OF NEUROSURGERY-PEDIATRICS Alexiades, N. G., Ahn, E. S., Blount, J. P., Brockmeyer, D. L., Browd, S. R., Grant, G. A., Heuer, G. G., Hankinson, T. C., Iskandar, B. J., Jea, A., Krieger, M. D., Leonard, J. R., Limbrick, D. D., Maher, C. O., Proctor, M. R., Sandberg, D., Wellons, J. C., Shao, B., Feldstein, N. A., Anderson, R. E. 2018; 22 (6): 701–9

  Abstract

  OBJECTIVEComplications after complex tethered spinal cord (cTSC) surgery include infections and cerebrospinal fluid (CSF) leaks. With little empirical evidence to guide management, there is variability in the interventions undertaken to limit complications. Expert-based best practices may improve the care of patients undergoing cTSC surgery. Here, authors conducted a study to identify consensus-driven best practices.METHODSThe Delphi method was employed to identify consensual best practices. A literature review regarding cTSC surgery together with a survey of current practices was distributed to 17 board-certified pediatric neurosurgeons. Thirty statements were then formulated and distributed to the group. Results of the second survey were discussed during an in-person meeting leading to further consensus, which was defined as ≥ 80% agreement on a 4-point Likert scale (strongly agree, agree, disagree, strongly disagree).RESULTSSeventeen consensus-driven best practices were identified, with all participants willing to incorporate them into their practice. There were four preoperative interventions: (1, 2) asymptomatic AND symptomatic patients should be referred to urology preoperatively, (3, 4) routine preoperative urine cultures are not necessary for asymptomatic AND symptomatic patients. There were nine intraoperative interventions: (5) patients should receive perioperative cefazolin or an equivalent alternative in the event of allergy, (6) chlorhexidine-based skin preparation is the preferred regimen, (7) saline irrigation should be used intermittently throughout the case, (8) antibiotic-containing irrigation should be used following dural closure, (9) a nonlocking running suture technique should be used for dural closure, (10) dural graft overlay should be used when unable to obtain primary dural closure, (11) an expansile dural graft should be incorporated in cases of lipomyelomeningocele in which primary dural closure does not permit free flow of CSF, (12) paraxial muscles should be closed as a layer separate from the fascia, (13) routine placement of postoperative drains is not necessary. There were three postoperative interventions: (14) postoperative antibiotics are an option and, if given, should be discontinued within 24 hours; (15) patients should remain flat for at least 24 hours postoperatively; (16) routine use of abdominal binders or other compressive devices postoperatively is not necessary. One intervention was prioritized for additional study: (17) further study of additional gram-negative perioperative coverage is needed.CONCLUSIONSA modified Delphi technique was used to develop consensus-driven best practices for decreasing wound complications after cTSC surgery. Further study is required to determine if implementation of these practices will lead to reduced complications. Discussion through the course of this study resulted in the initiation of a multicenter study of gram-negative surgical site infections in cTSC surgery.

  View details for PubMedID 30215584

• MULTICENTER, PROSPECTIVE VALIDATION OF AUTOMATED INTRAOPERATIVE NEUROPATHOLOGY USING STIMULATED RAMAN HISTOLOGY AND CONVOLUTIONAL NEURAL NETWORKS Hollon, T., Pandian, B., Heth, J., Sagher, O., Maher, C., Sullivan, S., Garton, H., Thompson, G., Save, A., Marie, T., Boyett, D., Petridis, P., McKhann, G., Muraszko, K., Bruce, J., Camelo-Piragua, S., Canoll, P., Orringer, D. OXFORD UNIV PRESS INC. 2018: 183

  View details for Web of Science ID 000460646301112

• Clinically Integrated Sequencing Alters Therapy in Children and Young Adults With High-Risk Glial Brain Tumors Harisowmiya JCO PRECISION ONCOLOGY Koschmann, C., Wu, Y., Kumar-Sinha, C., Lonigro, R., Vats, P., Kasaian, K., Cieslik, M., Cao, X., Anderson, B., Frank, K., Zhao, L., Prensner, J. R., Zureick, A. H., Everett, J., Mullan, B., Marini, B., Camelo-Piragua, S., Venneti, S., McKeever, P., McFadden, K., Lieberman, A. P., Leonard, M., Maher, C. O., Garton, H., Muraszko, K., Robertson, P., Robinson, D., Chinnaiyan, A. M., Mody, R. 2018; 2: 1-34

  Abstract

  Brain tumors have become the leading cause of cancer-related mortality in young patients. Novel effective therapies on the basis of the unique biology of each tumor are urgently needed. The goal of this study was to evaluate the feasibility, utility, and clinical impact of integrative clinical sequencing and genetic counseling in children and young adults with high-risk brain tumors.Fifty-two children and young adults with brain tumors designated by the treating neuro-oncologist to be high risk (> 25% chance for treatment failure; mean age, 10.2 years; range, 0 to 39 years) were enrolled in a prospective, observational, consecutive case series, in which participants underwent integrative clinical exome (tumor and germline DNA) and transcriptome (tumor RNA) sequencing and genetic counseling. Results were discussed in a multi-institutional brain tumor precision medicine teleconference.Sequencing revealed a potentially actionable germline or tumor alteration in 25 (63%) of 40 tumors with adequate tissue, of which 21 (53%) resulted in an impact on treatment or change of diagnosis. Platelet-derived growth factor receptor or fibroblast growth factor receptor pathway alterations were seen in nine of 20 (45%) glial tumors. Eight (20%) sequenced tumors harbored an oncogenic fusion isolated on RNA sequencing. Seventeen of 20 patients (85%) with glial tumors were found to have a potentially actionable result, which resulted in change of therapy in 14 (70%) patients. Patients with recurrent brain tumors receiving targeted therapy had a median progression-free survival (from time on therapy) of 4 months.Selection of personalized agents for children and young adults with highrisk brain tumors on the basis of integrative clinical sequencing is feasible and resulted in a change in therapy in more than two thirds of children and young adults with high-risk glial tumors.

  View details for DOI 10.1200/PO.17.00133

  View details for Web of Science ID 000462069400001

  View details for PubMedID 32832832

  View details for PubMedCentralID PMC7434092

• A Retrospective 2D Morphometric Analysis of Adult Female Chiari Type I Patients with Commonly Reported and Related Conditions FRONTIERS IN NEUROANATOMY Eppelheimer, M. S., Houston, J. R., Bapuraj, J. R., Labuda, R., Loth, D. M., Braun, A. M., Allen, N. J., Pahlavian, S., Biswas, D., Urbizu, A., Martin, B. A., Maher, C. O., Allen, P. A., Loth, F. 2018; 12: 2

  Abstract

  Purpose: Researchers have sought to better understand Chiari type I malformation (CMI) through morphometric measurements beyond tonsillar position (TP). Soft tissue and bone structures within the brain and craniocervical junction have been shown to be different for CMI patients compared to healthy controls. Yet, several morphological characteristics have not been consistently associated with CMI. CMI is also associated with different prevalent conditions (PCs) such as syringomyelia, pseudotumor, Ehlers-Danlos syndrome (EDS), scoliosis, and craniocervical instability. The goal of this study was two-fold: (1) to identify unique morphological characteristics of PCs, and (2) to better explain inconsistent results from case-control comparisons of CMI. Methods: Image, demographic, and PC information was obtained through the Chiari1000, a self-report web-accessed database. Twenty-eight morphometric measurements (MMs) were performed on the cranial MR images of 236 pre-surgery adult female CMI participants and 140 female healthy control participants. Custom software was used to measure 28 structures within the posterior cranial fossa (PCF) compartment, craniocervical junction, oral cavity, and intracranial area on midsagittal MR images for each participant. Results: Morphometric analysis of adult females indicated a smaller McRae line length in CMI participants with syringomyelia compared to those without syringomyelia. TP was reduced in CMI participants with EDS than those without EDS. Basion to posterior axial line was significantly longer in CMI participants with scoliosis compared to those without scoliosis. No additional MMs were found to differ between CMI participants with and without a specific PC. Four morphometric differences were found to be consistently different between CMI participants and healthy controls regardless of PC: larger TP and a smaller clivus length, fastigium, and corpus callosum height in CMI participants. Conclusion: Syringomyelia, EDS, and scoliosis were the only PCs that showed significant morphometric differences between CMI participants. Additionally, four midsagittal MR-based MMs were found to be significantly different between healthy controls and CMI participants regardless of the presence of one or more PCs. This study suggests that the prevalence of comorbid conditions are not strongly related to CMI morphology, and that inconsistent findings in the radiographic literature cannot be explained by varying prevalence of comorbid conditions in CMI study samples.

  View details for DOI 10.3389/fnana.2018.00002

  View details for Web of Science ID 000422979200001

  View details for PubMedID 29403363

  View details for PubMedCentralID PMC5785719

• Rapid Intraoperative Diagnosis of Pediatric Brain Tumors Using Stimulated Raman Histology CANCER RESEARCH Hollon, T. C., Lewis, S., Pandian, B., Niknafs, Y. S., Garrard, M. R., Garton, H., Maher, C. O., McFadden, K., Snuderl, M., Lieberman, A. P., Muraszko, K., Camelo-Piragua, S., Orringer, D. A. 2018; 78 (1): 278-289

  Abstract

  Accurate histopathologic diagnosis is essential for providing optimal surgical management of pediatric brain tumors. Current methods for intraoperative histology are time- and labor-intensive and often introduce artifact that limit interpretation. Stimulated Raman histology (SRH) is a novel label-free imaging technique that provides intraoperative histologic images of fresh, unprocessed surgical specimens. Here we evaluate the capacity of SRH for use in the intraoperative diagnosis of pediatric type brain tumors. SRH revealed key diagnostic features in fresh tissue specimens collected from 33 prospectively enrolled pediatric type brain tumor patients, preserving tumor cytology and histoarchitecture in all specimens. We simulated an intraoperative consultation for 25 patients with specimens imaged using both SRH and standard hematoxylin and eosin histology. SRH-based diagnoses achieved near-perfect diagnostic concordance (Cohen's kappa, κ > 0.90) and an accuracy of 92% to 96%. We then developed a quantitative histologic method using SRH images based on rapid image feature extraction. Nuclear density, tumor-associated macrophage infiltration, and nuclear morphology parameters from 3337 SRH fields of view were used to develop and validate a decision-tree machine-learning model. Using SRH image features, our model correctly classified 25 fresh pediatric type surgical specimens into normal versus lesional tissue and low-grade versus high-grade tumors with 100% accuracy. Our results provide insight into how SRH can deliver rapid diagnostic histologic data that could inform the surgical management of pediatric brain tumors.Significance: A new imaging method simplifies diagnosis and informs decision making during pediatric brain tumor surgery. Cancer Res; 78(1); 278-89. ©2017 AACR.

  View details for DOI 10.1158/0008-5472.CAN-17-1974

  View details for Web of Science ID 000419174000025

  View details for PubMedID 29093006

  View details for PubMedCentralID PMC5844703

• Middle Fossa Arachnoid Cysts Neurosurgery Case Series: Pediatric Bruzek , A., Maher , C. Selden NR, Baird LC Oxford University Press. 2018: 231-239
• Early Delivery of Sacrococcygeal Teratoma with Intraspinal Extension FETAL DIAGNOSIS AND THERAPY Perrone, E. E., Jarboe, M. D., Maher, C. O., Berman, D. R., Ladino-Torres, M., Kreutzman, J., Treadwell, M. C., Mychaliska, G. B. 2018; 43 (1): 72-76

  Abstract

  Sacrococcygeal teratoma (SCT) with intraspinal extension is rare. There is a risk of paraplegia associated with prolonged spinal cord compression. We present the case of an infant with a prenatal diagnosis of an SCT with a large intraspinal component that was causing compression of the lower spinal cord. Ultrasound at 33 weeks showed bilateral lower extremity and foot movement without hydrops or cardiac failure. Multidisciplinary decision was made to administer betamethasone and proceed with Cesarean delivery at 34 weeks. A vigorous live-born female was delivered and a multilevel laminectomy was performed at day of life 4. The pelvic resection was performed at 4 months. Pathology revealed mature teratoma. She had an uncomplicated postoperative course, is ambulatory, continent of stool, and has no evidence of recurrence. We conclude that intraspinal extension of SCT should be evaluated prenatally with ultrasound and fetal MRI. If there is concern for spinal cord compression, early delivery and urgent decompressive laminectomy may diminish the neurologic sequelae of prolonged spinal cord compression. Since these cases are rare, risks of prematurity need to be weighed against the neurologic risks. These infants should be treated with a multidisciplinary approach.

  View details for DOI 10.1159/000472714

  View details for Web of Science ID 000422846000011

  View details for PubMedID 28463844

• Morphometric and volumetric comparison of 102 children with symptomatic and asymptomatic Chiari malformation Type I JOURNAL OF NEUROSURGERY-PEDIATRICS Khalsa, S. S., Geh, N., Martin, B. A., Allen, P. A., Strahle, J., Loth, F., Habtzghi, D., Serrano, A., McQuaide, D., Garton, H. L., Muraszko, K. M., Maher, C. O. 2018; 21 (1): 65-71

  Abstract

  OBJECTIVE Chiari malformation Type I (CM-I) is typically defined on imaging by a cerebellar tonsil position ≥ 5 mm below the foramen magnum. Low cerebellar tonsil position is a frequent incidental finding on brain or cervical spine imaging, even in asymptomatic individuals. Nonspecific symptoms (e.g., headache and neck pain) are common in those with low tonsil position as well as in those with normal tonsil position, leading to uncertainty regarding appropriate management for many patients with low tonsil position and nonspecific symptoms. Because cerebellar tonsil position is not strictly correlated with the presence of typical CM-I symptoms, the authors sought to determine if other 2D morphometric or 3D volumetric measurements on MRI could distinguish between patients with asymptomatic and symptomatic CM-I. METHODS The authors retrospectively analyzed records of 102 pediatric patients whose records were in the University of Michigan clinical CM-I database. All patients in this database had cerebellar tonsil position ≥ 5 mm below the foramen magnum. Fifty-one symptomatic and 51 asymptomatic patients were matched for age at diagnosis, sex, tonsil position, and tonsil morphology. National Institutes of Health ImageJ software was used to obtain six 2D anatomical MRI measurements, and a semiautomated segmentation tool was used to obtain four 3D volumetric measurements of the posterior fossa and CSF subvolumes on MRI. RESULTS No significant differences were observed between patients with symptomatic and asymptomatic CM-I related to tentorium length (50.3 vs 51.0 mm; p = 0.537), supraoccipital length (39.4 vs 42.6 mm; p = 0.055), clivus-tentorium distance (52.0 vs 52.1 mm; p = 0.964), clivus-torcula distance (81.5 vs 83.3 mm; p = 0.257), total posterior fossa volume (PFV; 183.4 vs 190.6 ml; p = 0.250), caudal PFV (152.5 vs 159.8 ml; p = 0.256), fourth ventricle volume to caudal PFV ratio (0.0140 vs 0.0136; p = 0.649), or CSF volume to caudal PFV ratio (0.071 vs 0.061; p = 0.138). CONCLUSIONS No clinically useful 2D or 3D measurements were identified that could reliably distinguish pediatric patients with symptoms attributable to CM-I from those with asymptomatic CM-I.

  View details for DOI 10.3171/2017.8.PEDS17345

  View details for Web of Science ID 000418908800013

  View details for PubMedID 29125445

• CLINICALLY INTEGRATED SEQUENCING SIGNIFICANTLY ALTERS THERAPY IN CHILDREN AND YOUNG ADULTS WITH HIGH-RISK GLIAL BRAIN TUMORS Koschmann, C., Wu, Y., Kumar, C., Lonigro, R., Vats, P., Kasaian, K., Cieslik, M., Cao, X., Frank, K., Prensner, J. R., Zureick, A., Everett, J., Anderson, B., Mullan, B., Marini, B., Camelo-Piragua, S., Vennneti, S., Mc Keever, P., McFadden, K. A., Lieberman, A., Leonard, M., Maher, C. O., Garton, H. L., Muraszko, K., Robertson, P., Robinson, D., Chinnaiyan, A., Mody, R. OXFORD UNIV PRESS INC. 2017: 187

  View details for Web of Science ID 000415152503120

• RAPID ACCURATE INTRAOPERATIVE DIAGNOSIS OF PEDIATRIC BRAIN TUMORS USING STIMULATED RAMAN HISTOLOGY Hollon, T. C., Lewis, S., Pandian, B., Niknafs, Y., Garton, H. L., Maher, C. O., Muraszko, K., Camelo-Piragua, S., Orringer, D. A. OXFORD UNIV PRESS INC. 2017: 146-147

  View details for Web of Science ID 000415152502209

• Blood-brain barrier-adapted precision medicine therapy for pediatric brain tumors TRANSLATIONAL RESEARCH Marini, B. L., Benitez, L. L., Zureick, A. H., Salloum, R., Gauthier, A. C., Brown, J., Wu, Y., Robinson, D. R., Kumar, C., Lonigro, R., Vats, P., Cao, X., Kasaian, K., Anderson, B., Mullan, B., Chandler, B., Linzey, J. R., Camelo-Piragua, S. I., Venneti, S., McKeever, P. E., McFadden, K. A., Lieberman, A. P., Brown, N., Shao, L., Leonard, M. S., Junck, L., McKean, E., Maher, C. O., Garton, H. L., Muraszko, K. M., Hervey-Jumper, S., Mulcahy-Levy, J. M., Green, A., Hoffman, L. M., Dorris, K., Vitanza, N. A., Wang, J., Schwartz, J., Lulla, R., Smiley, N., Bornhorst, M., Haas-Kogan, D. A., Robertson, P. L., Chinnaiyan, A. M., Mody, R., Koschmann, C. 2017; 188: 27-39

  Abstract

  Targeted chemotherapeutics provide a promising new treatment option in neuro-oncology. The ability of these compounds to penetrate the blood-brain barrier is crucial for their successful incorporation into patient care. "CNS Targeted Agent Prediction" (CNS-TAP) is a multi-institutional and multidisciplinary translational program established at the University of Michigan for evaluating the central nervous system (CNS) activity of targeted therapies in neuro-oncology. In this report, we present the methodology of CNS-TAP in a series of pediatric and adolescent patients with high-risk brain tumors, for which molecular profiling (academic and commercial) was sought and targeted agents were incorporated. Four of five of the patients had potential clinical benefit (partial response or stable disease greater than 6 months on therapy). We further describe the specific drug properties of each agent chosen and discuss characteristics relevant in their evaluation for therapeutic suitability. Finally, we summarize both tumor and drug characteristics that impact the ability to successfully incorporate targeted therapies into CNS malignancy management.

  View details for DOI 10.1016/j.trsl.2017.08.001

  View details for Web of Science ID 000411778000003

  View details for PubMedID 28860053

  View details for PubMedCentralID PMC5584679

• Screening for spine injury in abusive head trauma JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O. 2017; 20 (3): 269-270

  View details for DOI 10.3171/2017.3.PEDS1775

  View details for Web of Science ID 000408303900010

  View details for PubMedID 28665243

• Stimulated Raman histology in brain tumors: A label free microscopic technique utilizing fresh unprocessed tissue Camelo-Piragua, S., Camelo-Piragua, S., Pandian, B., Niknafs, Y., Hollon, T., Boyle, J., Lewis, S., Garrard, M., Hervey-Jumper, S., Garton, H., Maher, C., Heth, J., Sagher, O., Wilkinson, D., Snuderl, M., Venneti, S., Ramkissoon, S., McFadden, K., Fisher-Hubbard, A., Lieberman, A., Johnson, T., Xie, X., Trautman, J., Freudiger, C., Orringer, D. OXFORD UNIV PRESS INC. 2017: 525

  View details for Web of Science ID 000404906900142

• STIMULATED RAMAN SCATTERING MICROSCOPY PROVIDES RAPID, DIAGNOSTIC HISTOPATHOLOGIC IMAGES DURING PEDIATRIC BRAIN TUMOR SURGERY Hollon, T., Garrard, M., Tarpeh, J., Pandian, B., Niknafs, Y., Garton, H., Maher, C., Muraszko, K., Camelo-Piragua, S., Orringer, D. OXFORD UNIV PRESS INC. 2017: 51

  View details for Web of Science ID 000402766800216

• Brainstem Low-Grade Gliomas in Children-Excellent Outcomes With Multimodality Therapy JOURNAL OF CHILD NEUROLOGY Upadhyaya, S. A., Koschmann, C., Muraszko, K., Venneti, S., Garton, H. J., Hamstra, D. A., Maher, C. O., Betz, B. L., Brown, N. A., Wahl, D., Weigelin, H. C., DuRoss, K. E., Leonard, A. S., Robertson, P. L. 2017; 32 (2): 194-203

  Abstract

  Safe maximal surgical resection is the initial treatment of choice for pediatric brainstem low-grade gliomas. Optimal therapy for incompletely resected tumors or that progress after surgery is uncertain. We reviewed the clinical characteristics, therapy, and outcomes of all children with nontectal brainstem low-grade gliomas treated at the University of Michigan between 1993 and 2013. Median age at diagnosis was 6 years; histology was confirmed in 23 of 25 tumors, 64% were pilocytic astrocytoma. Nineteen patients underwent initial tumor resection; 14/19 received no upfront adjuvant therapy. Eight patients in the study had progressive disease; 5 initially resected tumors received chemotherapy at tumor relapse, all with partial or complete radiographic responses. Ten-year progression-free survival is 71% and overall survival, 100%. This single-institution retrospective study demonstrates excellent survival rates for children with brainstem low-grade gliomas. The efficacy of the well-tolerated chemotherapy in this series supports its role in the treatment of unresectable or progressive brainstem low-grade gliomas.

  View details for DOI 10.1177/0883073816675547

  View details for Web of Science ID 000397213600007

  View details for PubMedID 27810966

  View details for PubMedCentralID PMC5582383

• Trends in surgical treatment of Chiari malformation Type I in the United States JOURNAL OF NEUROSURGERY-PEDIATRICS Wilkinson, D., Johnson, K., Garton, H. L., Muraszko, K. M., Maher, C. O. 2017; 19 (2): 208-216

  Abstract

  OBJECTIVE The goal of this analysis was to define temporal and geographic trends in the surgical treatment of Chiari malformation Type I (CM-I) in a large, privately insured health care network. METHODS The authors examined de-identified insurance claims data from a large, privately insured health care network of over 58 million beneficiaries throughout the United States for the period between 2001 and 2014 for all patients undergoing surgical treatment of CM-I. Using a combination of International Classification of Diseases (ICD) diagnosis codes and Current Procedural Terminology (CPT) codes, the authors identified CM-I and associated diagnoses and procedures over a 14-year period, highlighting temporal and geographic trends in the performance of CM-I decompression (CMD) surgery as well as commonly associated procedures. RESULTS There were 2434 surgical procedures performed for CMD among the beneficiaries during the 14-year interval; 34% were performed in patients younger than 20 years of age. The rate of CMD increased 51% from the first half to the second half of the study period among younger patients (p < 0.001) and increased 28% among adult patients between 20 and 65 years of age (p < 0.001). A large sex difference was noted among adult patients; 78% of adult patients undergoing CMD were female compared with only 53% of the children. Pediatric patients undergoing CMD were more likely to be white with a higher household net worth. Regional variability was identified among rates of CMD as well. The average annual rate of surgery ranged from 0.8 surgeries per 100,000 insured person-years in the Pacific census division to 2.0 surgeries per 100,000 insured person-years in the East South Central census division. CONCLUSIONS Analysis of a large nationwide health care network showed recently increasing rates of CMD in children and adults over the past 14 years.

  View details for DOI 10.3171/2016.8.PEDS16273

  View details for Web of Science ID 000393089000009

  View details for PubMedID 27834622

• Rapid intraoperative histology of unprocessed surgical specimens via fibre-laser-based stimulated Raman scattering microscopy NATURE BIOMEDICAL ENGINEERING Orringer, D. A., Pandian, B., Niknafs, Y. S., Hollon, T. C., Boyle, J., Lewis, S., Garrard, M., Hervey-Jumper, S. L., Garton, H. L., Maher, C. O., Heth, J. A., Sagher, O., Wilkinson, D., Snuderl, M., Venneti, S., Ramkissoon, S. H., McFadden, K. A., Fisher-Hubbard, A., Lieberman, A. P., Johnson, T. D., Xie, X., Trautman, J. K., Freudiger, C. W., Camelo-Piragua, S. 2017; 1 (2)

  Abstract

  Conventional methods for intraoperative histopathologic diagnosis are labour- and time-intensive, and may delay decision-making during brain-tumour surgery. Stimulated Raman scattering (SRS) microscopy, a label-free optical process, has been shown to rapidly detect brain-tumour infiltration in fresh, unprocessed human tissues. Here, we demonstrate the first application of SRS microscopy in the operating room by using a portable fibre-laser-based microscope and unprocessed specimens from 101 neurosurgical patients. We also introduce an image-processing method - stimulated Raman histology (SRH) - which leverages SRS images to create virtual haematoxylin-and-eosin-stained slides, revealing essential diagnostic features. In a simulation of intraoperative pathologic consultation in 30 patients, we found a remarkable concordance of SRH and conventional histology for predicting diagnosis (Cohen's kappa, κ > 0.89), with accuracy exceeding 92%. We also built and validated a multilayer perceptron based on quantified SRH image attributes that predicts brain-tumour subtype with 90% accuracy. Our findings provide insight into how SRH can now be used to improve the surgical care of brain tumour patients.

  View details for DOI 10.1038/s41551-016-0027

  View details for Web of Science ID 000418853900005

  View details for PubMedID 28955599

  View details for PubMedCentralID PMC5612414

• STIMULATED RAMAN SCATTERING MICROSCOPY PROVIDES DIAGNOSTIC INTRAOPERATIVE HISTOPATHOLOGIC IMAGES IN BRAIN TUMOR PATIENTS Orringer, D. A., Pandian, B., Hollon, T. C., Niknafs, Y. S., Boyle, J., Lewis, S., Hervey-Jumper, S. L., Garton, H. L., Maher, C. O., Heth, J. A., Sagher, O., Snuderl, M., Venneti, S., Ramkissoon, S., McFadden, K. A., Fisher-Hubbard, A., Lieberman, A., Johnson, T. D., Xie, X., Freudiger, C. W., Camelo-Piragua, S. OXFORD UNIV PRESS INC. 2016: 193

  View details for Web of Science ID 000398604104125

• CLINICALLY INTEGRATED SEQUENCING IN THE MANAGEMENT OF CHILDREN WITH HIGH-RISK BRAIN TUMORS Koschmann, C., Marini, B., Colon, L., Wu, Y., Kumar, C., Lonigro, R., Vats, P., Cao, X., Zamler, D., Camelo-Piragua, S., Vennneti, S., Mc Keever, P., McFadden, K., Lieberman, A., Shao, L., Fisher-Hubbard, A., Gupta, A., Pritula, L., Everett, J., Jacobs, M., Mcdougall, R., Leonard, M., Maher, C., Garton, H., Muraszko, K., Lowenstein, P. R., Castro, M. G., Robinson, D., Chinnaiyan, A., Mody, R. OXFORD UNIV PRESS INC. 2016: 145-146

  View details for Web of Science ID 000398604103122

• Are arachnoid cysts and Chiari malformation Type I more common in those with postconcussion syndrome? JOURNAL OF NEUROSURGERY Strahle, J., Maher, C. O. 2016; 125 (5): 1320-1321

  View details for DOI 10.3171/2016.5.JNS161269

  View details for Web of Science ID 000386106100036

  View details for PubMedID 27611207

• Morphometric analysis of the developing pediatric cervical spine JOURNAL OF NEUROSURGERY-PEDIATRICS Johnson, K. T., Al-Holou, W. N., Anderson, R. C., Wilson, T. J., Karnati, T., Ibrahim, M., Garton, H. J., Maher, C. O. 2016; 18 (3): 377-389

  Abstract

  OBJECTIVE Our understanding of pediatric cervical spine development remains incomplete. The purpose of this analysis was to quantitatively define cervical spine growth in a population of children with normal CT scans. METHODS A total of 1458 children older than 1 year and younger than 18 years of age who had undergone a cervical spine CT scan at the authors' institution were identified. Subjects were separated by sex and age (in years) into 34 groups. Following this assignment, subjects within each group were randomly selected for inclusion until a target of 15 subjects in each group had been measured. Linear measurements were performed on the midsagittal image of the cervical spine. Twenty-three unique measurements were obtained for each subject. RESULTS Data showed that normal vertical growth of the pediatric cervical spine continues up to 18 years of age in boys and 14 years of age in girls. Approximately 75% of the vertical growth occurs throughout the subaxial spine and 25% occurs across the craniovertebral region. The C-2 body is the largest single-segment contributor to vertical growth, but the subaxial vertebral bodies and disc spaces also contribute. Overall vertical growth of the cervical spine throughout childhood is dependent on individual vertebral body growth as well as vertical growth of the disc spaces. The majority of spinal canal diameter growth occurs by 4 years of age. CONCLUSIONS The authors' morphometric analyses establish parameters for normal pediatric cervical spine growth up to 18 years of age. These data should be considered when evaluating children for potential surgical intervention and provide a basis of comparison for studies investigating the effects of cervical spine instrumentation and fusion on subsequent growth.

  View details for DOI 10.3171/2016.3.PEDS1612

  View details for Web of Science ID 000381781300017

  View details for PubMedID 27231821

• Cerebrospinal fluid velocity amplitudes within the cerebral aqueduct in healthy children and patients with Chiari I malformation JOURNAL OF MAGNETIC RESONANCE IMAGING Bapuraj, J., Londy, F. J., Delavari, N., Maher, C. O., Garton, H. L., Martin, B. A., Muraszko, K. M., Ibrahim, E. H., Quint, D. J. 2016; 44 (2): 463-470

  Abstract

  To assess the effects of cerebrospinal fluid (CSF) bidirectional motion in Chiari malformation type I (CMI), we monitored CSF velocity amplitudes on phase contrast MRI (PC-MRI) in patients before and after surgery; and in healthy volunteers.10 pediatric volunteers and 10 CMI patients participated in this study. CMI patients underwent PC-MRI scans before and approximately 14 months following surgery. Two parameters-amplitude of mean velocity (AMV) and amplitude of peak velocity (APV) of CSF-were derived from the data. Measurements were made at the mid-portion of the cerebral aqueduct, and anterior and posterior compartments of the spinal canal at the craniovertebral junction (CVJ).AMV and APV within the cerebral aqueduct were greater in preoperative assessments of the CMI patients compared to normal volunteers. Statistical significance was noted when comparing aqueductal AMV between the preoperative values and normal controls (P = 0.03), and before and after surgery in the CMI patients (P = 0.02). Lower values of AMV (P = 0.02) were noted in the anterior CVJ compartment in the patients before and after surgery when compared to the normal volunteers. There were no significant correlations (P = 0.06) noted for the APV at the CVJ between the normal control and patients, before or after surgery.In pediatric CMI patients, AMV for CSF within the cerebral aqueduct and anterior CVJ subarachnoid space are significantly elevated preoperatively and normalize following surgery. Given the biphasic CSF motion, measuring amplitude accounts for cranial and caudal flow. It may offer an alternative parameter to assess postsurgical outcome. J. Magn. Reson. Imaging 2016;44:463-470.

  View details for DOI 10.1002/jmri.25160

  View details for Web of Science ID 000380068100023

  View details for PubMedID 26788935

• Sports participation with arachnoid cysts JOURNAL OF NEUROSURGERY-PEDIATRICS Strahle, J., Selzer, B. J., Geh, N., Srinivasan, D., Strahle, M., Martinez-Sosa, M., Muraszko, K. M., Garton, H. L., Maher, C. O. 2016; 17 (4): 410-417

  Abstract

  OBJECT There is currently no consensus on the safety of sports participation for patients with an intracranial arachnoid cyst (AC). The authors' goal was to define the risk of sports participation for children with this imaging finding. METHODS A survey was prospectively administered to 185 patients with ACs during a 46-month period at a single institution. Cyst size and location, treatment, sports participation, and any injuries were recorded. Eighty patients completed at least 1 subsequent survey following their initial entry into the registry, and these patients were included in a prospective registry with a mean prospective follow-up interval of 15.9 ± 8.8 months. RESULTS A total 112 patients with ACs participated in 261 sports for a cumulative duration of 4410 months or 1470 seasons. Of these, 94 patients participated in 190 contact sports for a cumulative duration of 2818 months or 939 seasons. There were no serious or catastrophic neurological injuries. Two patients presented with symptomatic subdural hygromas following minor sports injuries. In the prospective cohort, there were no neurological injuries CONCLUSIONS Permanent or catastrophic neurological injuries are very unusual in AC patients who participate in athletic activities. In most cases, sports participation by these patients is safe.

  View details for DOI 10.3171/2015.7.PEDS15189

  View details for Web of Science ID 000372669600007

  View details for PubMedID 26636254

• Sports participation with Chiari I malformation JOURNAL OF NEUROSURGERY-PEDIATRICS Strahle, J., Geh, N., Selzer, B. J., Bower, R., Himedan, M., Strahle, M., Wetjen, N. M., Muraszko, K. M., Garton, H. L., Maher, C. O. 2016; 17 (4): 403-409

  Abstract

  OBJECT There is currently no consensus on the safety of sports participation for patients with Chiari I malformation (CM-I). The authors' goal was to define the risk of sports participation for children with the imaging finding of CM-I. METHODS A prospective survey was administered to 503 CM-I patients at 2 sites over a 46-month period. Data were gathered on imaging characteristics, treatment, sports participation, and any sport-related injuries. Additionally, 81 patients completed at least 1 subsequent survey following their initial entry into the registry and were included in a prospective group, with a mean prospective follow-up period of 11 months. RESULTS Of the 503 CM-I patients, 328 participated in sports for a cumulative duration of 4641 seasons; 205 of these patients participated in contact sports. There were no serious or catastrophic neurological injuries. One patient had temporary extremity paresthesias that resolved within hours, and this was not definitely considered to be related to the CM-I. In the prospective cohort, there were no permanent neurological injuries. CONCLUSIONS No permanent or catastrophic neurological injuries were observed in CM-I patients participating in athletic activities. The authors believe that the risk of such injuries is low and that, in most cases, sports participation by children with CM-I is safe.

  View details for DOI 10.3171/2015.8.PEDS15188

  View details for Web of Science ID 000372669600006

  View details for PubMedID 26636249

• Children With Arachnoid Cysts Who Sustain Blunt Head Trauma: Injury Mechanisms and Outcomes ACADEMIC EMERGENCY MEDICINE Rogers, A. J., Kuppermann, N., Thelen, A. E., Stanley, R. M., Maher, C. O. 2016; 23 (3): 358-361

  Abstract

  Arachnoid cysts are abnormal intracranial fluid collections, and there is concern that these cysts may bleed or rupture following blunt head trauma. Our objective was to determine the risk of cyst-related complications in a cohort of children with arachnoid cysts who were evaluated for head trauma.We analyzed the Pediatric Emergency Care Applied Research Network (PECARN) head trauma public use data set, which was the product of a study that enrolled children with blunt head trauma from June 2004 to September 2006. We identified children with arachnoid cysts on cranial computed tomography (CT) and described the patient demographics, mechanisms of injury, clinical presentations, CT evidence of traumatic brain injury (TBI), and clinical outcomes. Clinically important TBI was defined as TBI leading to: 1) death from TBI, 2) neurosurgical intervention, 3) intubation for > 24 hours for the TBI, or 4) hospitalization for 2 or more nights for the head injury in association with TBI on CT.Data were available for 43,399 children who sustained blunt head trauma, of whom 15,899 had cranial CT scans obtained and 68 (0.4%) had arachnoid cysts. Falls were the most common mechanisms of injury (47%) and 87% of children had either moderate or severe injury mechanisms. Glasgow Coma Scale (GCS) scores ranged from 6 to 15, with 61 (90%) having GCS scores of 15. Two of the children with arachnoid cysts had TBIs on CT, one of which was clinically important. There were no identified cases of arachnoid cyst-related bleeding or complications.In this cohort of 68 children with arachnoid cysts who sustained head trauma, none demonstrated cyst-related bleeding or complications. This suggests the risk of arachnoid cyst-related complications in children following blunt head trauma is low and evaluation should align with existing clinical decision rules.

  View details for DOI 10.1111/acem.12887

  View details for Web of Science ID 000373106300017

  View details for PubMedID 26728086

• Interobserver Variation in Cerebellar Tonsillar Tip Localization: Comparison of 3 Different Osseous Landmarks on Magnetic Resonance Imaging JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Moore, A. G., Gomez-Hassan, D., Quint, D. J., Garton, H. L., Maher, C. O., Srinivasan, A. 2016; 40 (1): 34-38

  Abstract

  The aim was to evaluate the interobserver agreement in the assessment of cerebellar tonsil position on sagittal magnetic resonance imaging using 3 different osseous landmarks.This retrospective study consisted of brain magnetic resonance imagings performed at our institution in patients with and without Chiari I malformation between January 2010 and 2012. Sagittal T1-weighted images were reviewed by 2 senior board-certified neuroradiologists (blinded to underlying clinical diagnosis) with measurement of both cerebellar tonsillar positions based on lines drawn perpendicular from the tonsillar tip to the foramen magnum [FM] line, C1 line, and C2 line. Spearman correlation coefficients were calculated. Interobserver variation between the readers was assessed using Bland-Altman analysis and intraclass correlation coefficient.A total of 320 cerebellar tonsils on 160 patients, 50 with Chiari I malformations, and 110 control subjects without Chiari I malformation were evaluated. The Spearman correlation coefficients for the entire cohort were 0.86 (FM), 0.94 (C1), and 0.90 (C2). Bland-Altman analysis for the entire cohort showed the best interobserver agreement for C1 line (-0.3 mm bias) and the least for C2 line (4.6 mm bias). The Intraclass correlation coefficients for all patients were 0.84 (FM), 0.92 (C1), and 0.54 (C2). The least bias and highest correlation coefficients were also seen individually in the Chiari and non-Chiari cohorts with the C1 technique.Determination of cerebellar tonsillar position using a C1 arch landmark may be superior to the currently more commonly used FM-based landmark with lesser interobserver variability and higher interobserver correlation.

  View details for DOI 10.1097/RCT.0000000000000326

  View details for Web of Science ID 000376899400004

  View details for PubMedID 26484958

• Stroke in Children PEDIATRIC NEUROSURGERY: TRICKS OF THE TRADE Maher, C. O., Cohen, A. 2016: 755-758

  View details for Web of Science ID 000562806000102

• Chiari malformation I and autism spectrum disorder JOURNAL OF NEUROSURGERY-PEDIATRICS Strahle, J., Maher, C. O. 2015; 16 (5): 609-610

  View details for DOI 10.3171/2015.2.PEDS1571

  View details for Web of Science ID 000363439700026

  View details for PubMedID 26273740

• Detection of human brain tumor infiltration with quantitative stimulated Raman scattering microscopy SCIENCE TRANSLATIONAL MEDICINE Ji, M., Lewis, S., Camelo-Piragua, S., Ramkissoon, S. H., Snuderl, M., Venneti, S., Fisher-Hubbard, A., Garrard, M., Fu, D., Wang, A. C., Heth, J. A., Maher, C. O., Sanai, N., Johnson, T. D., Freudiger, C. W., Sagher, O., Xie, X., Orringer, D. A. 2015; 7 (309): 309ra163

  Abstract

  Differentiating tumor from normal brain is a major barrier to achieving optimal outcome in brain tumor surgery. New imaging techniques for visualizing tumor margins during surgery are needed to improve surgical results. We recently demonstrated the ability of stimulated Raman scattering (SRS) microscopy, a nondestructive, label-free optical method, to reveal glioma infiltration in animal models. We show that SRS reveals human brain tumor infiltration in fresh, unprocessed surgical specimens from 22 neurosurgical patients. SRS detects tumor infiltration in near-perfect agreement with standard hematoxylin and eosin light microscopy (κ = 0.86). The unique chemical contrast specific to SRS microscopy enables tumor detection by revealing quantifiable alterations in tissue cellularity, axonal density, and protein/lipid ratio in tumor-infiltrated tissues. To ensure that SRS microscopic data can be easily used in brain tumor surgery, without the need for expert interpretation, we created a classifier based on cellularity, axonal density, and protein/lipid ratio in SRS images capable of detecting tumor infiltration with 97.5% sensitivity and 98.5% specificity. Quantitative SRS microscopy detects the spread of tumor cells, even in brain tissue surrounding a tumor that appears grossly normal. By accurately revealing tumor infiltration, quantitative SRS microscopy holds potential for improving the accuracy of brain tumor surgery.

  View details for DOI 10.1126/scitranslmed.aab0195

  View details for Web of Science ID 000365235100005

  View details for PubMedID 26468325

  View details for PubMedCentralID PMC4900155

• Prevalence of Chiari I Malformation and Syringomyelia NEUROSURGERY CLINICS OF NORTH AMERICA Kahn, E. N., Muraszko, K. M., Maher, C. O. 2015; 26 (4): 501-+

  Abstract

  Chiari I malformation (CM) is a common neurosurgical diagnosis and spinal cord syrinx is frequently found in patients with CM. Asymptomatic CM is a common imaging finding. Symptomatic CM is less common. Variation in prevalence estimates may be attributed to differences in sensitivity of CM detection between studies as well as differences in the populations being analyzed. The prevalence of low tonsil position and CM on MRI is higher in children and young adults compared with older adults. Studies that include a large number of older adults find a lower prevalence compared with analyses of children.

  View details for DOI 10.1016/j.nec.2015.06.006

  View details for Web of Science ID 000363434800004

  View details for PubMedID 26408058

• Skull fracture mimicking eosinophilic granuloma CHILDS NERVOUS SYSTEM Hollon, T., McKeever, P. E., Garton, H. L., Maher, C. O. 2015; 31 (7): 1171-1174

  Abstract

  Delayed swelling after skull fractures is an uncommon complication following head trauma in children. Classically, growing skull fractures typically present in patients under 3 years of age with progressive subcutaneous fluid collections, or occasionally with neurologic symptoms. We present the case of a healthy 2-year-old boy with a lytic "punched-out" frontal skull lesion. The child presented 2 months after a minor forehead injury for which no medical attention was sought.The skull defect had no associated leptomeningeal cyst or brain herniation. Imaging and presentation were thought to be consistent with eosinophilic granuloma. Histologic findings demonstrated a healing skull fracture.Cranioplasty was performed, and the patient had an uncomplicated postoperative course.In this report, we describe our experience with this atypical presentation of a healing skull fracture mimicking a typical eosinophilic granuloma.

  View details for DOI 10.1007/s00381-015-2676-8

  View details for Web of Science ID 000357483400024

  View details for PubMedID 25758644

• Impact of body mass index on cerebellar tonsil position in healthy subjects and patients with Chiari malformation JOURNAL OF NEUROSURGERY Smith, B. W., Strahle, J., Kazarian, E., Muraszko, K. M., Garton, H. L., Maher, C. O. 2015; 123 (1): 226-231

  Abstract

  It is unclear if there is a relationship between Chiari malformation Type I (CM-I) and body mass index (BMI). The aim of this study was to identify the relationship between BMI and cerebellar tonsil position in a random sample of people.Cerebellar tonsil position in 2400 subjects from a cohort of patients undergoing MRI was measured. Three hundred patients were randomly selected from each of 8 age groups (from 0 to 80 years). A subject was then excluded if he or she had a posterior fossa mass or previous posterior fossa decompression or if height and weight information within 1 year of MRI was not recorded in the electronic medical record.There were 1310 subjects (54.6%) with BMI records from within 1 year of the measured scan. Of these subjects, 534 (40.8%) were male and 776 (59.2%) were female. The average BMI of the group was 26.4 kg/m(2), and the average tonsil position was 0.87 mm above the level of the foramen magnum. There were 46 subjects (3.5%) with a tonsil position ≥ 5 mm below the level of the foramen magnum. In the group as a whole, there was no correlation (R(2) = 0.004) between BMI and cerebellar tonsil position.In this examination of 1310 subjects undergoing MRI for any reason, there was no relationship between BMI and the level of the cerebellar tonsils or the diagnosis of CM-I on imaging.

  View details for DOI 10.3171/2014.10.JNS141317

  View details for Web of Science ID 000356981200029

  View details for PubMedID 25839920

• Syrinx location and size according to etiology: identification of Chiari-associated syrinx JOURNAL OF NEUROSURGERY-PEDIATRICS Strahle, J., Muraszko, K. M., Garton, H. L., Smith, B. W., Starr, J., Kapurch, J. R., Maher, C. O. 2015; 16 (1): 21-29

  Abstract

  OBJECT Syrinx size and location within the spinal cord may differ based on etiology or associated conditions of the brain and spine. These differences have not been clearly defined. METHODS All patients with a syrinx were identified from 14,118 patients undergoing brain or cervical spine imaging at a single institution over an 11-year interval. Syrinx width, length, and location in the spinal cord were recorded. Patients were grouped according to associated brain and spine conditions including Chiari malformation Type I (CM-I), secondary CM (2°CM), Chiari malformation Type 0 (CM-0), tethered cord, other closed dysraphism, and spinal tumors. Syringes not associated with any known brain or spinal cord condition were considered idiopathic. Syrinx characteristics were compared between groups. RESULTS A total of 271 patients with a syrinx were identified. The most common associated condition was CM-I (occurring in 117 patients [43.2%]), followed by spinal dysraphism (20 [7.4%]), tumor (15 [5.5%]), and tethered cord (13 [4.8%]). Eighty-three patients (30.6%) did not have any associated condition of the brain or spinal cord and their syringes were considered idiopathic. Syringes in patients with CM-I were wide (7.8 ± 3.9 mm) compared with idiopathic syringes (3.9 ± 1.0, p < 0.0001) and those associated with tethered cord (4.2 ± 0.9, p < 0.01). When considering CM-I-associated and idiopathic syringes, the authors found that CM-I-associated syringes were more likely to have their cranial extent in the cervical spine (88%), compared with idiopathic syringes (43%; p < 0.0001). The combination of syrinx width greater than 5 mm and cranial extent in the cervical spine had 99% specificity (95% CI 0.92-0.99) for CM-I-associated syrinx. CONCLUSIONS Syrinx morphology differs according to syrinx etiology. The combination of width greater than 5 mm and cranial extent in the cervical spine is highly specific for CM-I-associated syringes. This may have relevance when determining the clinical significance of syringes in patients with low cerebellar tonsil position.

  View details for DOI 10.3171/2014.12.PEDS14463

  View details for Web of Science ID 000356981300005

  View details for PubMedID 25837888

• Use of Stimulated Raman Scattering Microscopy for Quantitative Brain Tumor Imaging Lewis, S., Ji, M., Camelo-Piragua, S., Venneti, S., Fisher-Hubbard, A., Garrard, M., Wang, A., Heth, J., Maher, C., Johnson, T., Sagher, O., Xie, X., Orringer, D. LIPPINCOTT WILLIAMS & WILKINS. 2015: 595

  View details for Web of Science ID 000354824800038

• The association between Chiari malformation Type I, spinal syrinx, and scoliosis JOURNAL OF NEUROSURGERY-PEDIATRICS Strahle, J., Smith, B. W., Martinez, M., Bapuraj, J., Muraszko, K. M., Garton, H. L., Maher, C. O. 2015; 15 (6): 607-611

  Abstract

  OBJECT Chiari malformation Type I (CM-I) is often found in patients with scoliosis. Most previous reports of CM-I and scoliosis have focused on patients with CM-I and a spinal syrinx. The relationship between CM-I and scoliosis in the absence of a syrinx has never been defined clearly. The authors sought to determine if there is an independent association between CM-I and scoliosis when controlling for syrinx status. METHODS The medical records of 14,118 consecutive patients aged ≤ 18 years who underwent brain or cervical spine MRI at a single institution in an 11-year span were reviewed to identify patients with CM-I, scoliosis, and/or syrinx. The relationship between CM-I and scoliosis was analyzed by using multivariate regression analysis and controlling for age, sex, CM-I status, and syrinx status. RESULTS In this cohort, 509 patients had CM-I, 1740 patients had scoliosis, and 243 patients had a spinal syrinx. The presence of CM-I, the presence of syrinx, older age, and female sex were each significantly associated with scoliosis in the univariate analysis. In the multivariate regression analysis, older age (OR 1.02 [95% CI 1.01-1.03]; p < 0.0001), female sex (OR 1.71 [95% CI 1.54-1.90]; p < 0.0001), and syrinx (OR 9.08 [95% CI 6.82-12.10]; p < 0.0001) were each independently associated with scoliosis. CM-I was not independently associated with scoliosis when controlling for these other variables (OR 0.99 [95% CI 0.79-1.29]; p = 0.9). CONCLUSIONS A syrinx was independently associated with scoliosis in a large pediatric population undergoing MRI. CM-I was not independently associated with scoliosis when controlling for age, sex, and syrinx status. Because CM-I is not independently associated with scoliosis, scoliosis should not necessarily be considered a symptom of low cerebellar tonsil position in patients without a syrinx.

  View details for DOI 10.3171/2014.11.PEDS14135

  View details for Web of Science ID 000355031500009

  View details for PubMedID 26030330

• Incidental findings on brain and spine imaging in children. Pediatrics Maher, C. O., Piatt, J. H. 2015; 135 (4): e1084-96

  Abstract

  In recent years, the utilization of diagnostic imaging of the brain and spine in children has increased dramatically, leading to a corresponding increase in the detection of incidental findings of the central nervous system. Patients with unexpected findings on imaging are often referred for subspecialty evaluation. Even with rational use of diagnostic imaging and subspecialty consultation, the diagnostic process will always generate unexpected findings that must be explained and managed. Familiarity with the most common findings that are discovered incidentally on diagnostic imaging of the brain and spine will assist the pediatrician in providing counseling to families and in making recommendations in conjunction with a neurosurgeon, when needed, regarding additional treatments and prognosis.

  View details for DOI 10.1542/peds.2015-0071

  View details for PubMedID 25825535

• Management of pediatric craniocervical arterial dissections CHILDS NERVOUS SYSTEM Pandey, A. S., Hill, E., Al-Holou, W. N., Gemmete, J. J., Chaudhary, N., Thompson, B., Garton, H. L., Maher, C. O. 2015; 31 (1): 101-107

  Abstract

  Craniocervical arterial dissections (CCADs) represent a preventable cause of acute ischemic stroke (AIS). Our objective was to describe clinical presentation, imaging features, treatment strategies, and report clinical and imaging outcomes of CCADs at a large pediatric tertiary referral center.Electronic medical records were queried using variations of the word dissection for patients under 25 years of age with neuroimaging over a 13-year period. Medical and imaging records were reviewed to identify carotid, vertebral, or intracranial dissections. Demographics, presenting symptoms, presence of AIS, mechanism of injury, dissection location, dissection treatment, and complications stemming from treatment were collected. Clinical outcome was classified according to modified Rankin Scale (mRS) score. Imaging follow-up was obtained until the dissection healed or stabilized.A total 6,289 patients met initial search criteria. Of the 42 (0.7%) patients with CCADs, 23 (54.8%) had internal carotid artery (ICA) dissections, and 17 (40.5%) had vertebrobasilar (VB) dissections. More females had ICA dissections (p = 0.002), and more males had VB dissections (p = 0.01). CCADs associated with traumatic presentation occurred in 34 patients (81.0%), while 8 (19.0%) were spontaneous. Good outcomes (mRS 0-3) were noted for 36 patients, and 5 had poor outcomes (mRS 4-6). In the 17 patients with vessel occlusion, 50.0% had partial or complete recanalization at a mean follow-up of 23.9 months.CCAD is commonly related to trauma and presents with AIS. The majority of patients experience good clinical outcome. Recanalization of initial vessel occlusion occurs in half of cases at 2 years.

  View details for DOI 10.1007/s00381-014-2547-8

  View details for Web of Science ID 000348115200012

  View details for PubMedID 25227167

• Pediatric Arteriovenous Malformations Youman and Winn's Neurological Surgery Maher , C., Wilkinson , A. Winn HR(ed.) Elsevier. 2015; 7th
• Role of Hemoglobin and Iron in Hydrocephalus After Neonatal Intraventricular Hemorrhage NEUROSURGERY Strahle, J. M., Garton, T., Bazzi, A. A., Kilaru, H., Garton, H. L., Maher, C. O., Muraszko, K. M., Keep, R. F., Xi, G. 2014; 75 (6): 696-705

  Abstract

  Neonatal germinal matrix hemorrhage/intraventricular hemorrhage is common and often results in hydrocephalus. The pathogenesis of posthemorrhagic hydrocephalus is not fully understood.To explore the potential role of hemoglobin and iron released after hemorrhage.Artificial cerebrospinal fluid (aCSF), hemoglobin, or iron was injected into the right lateral ventricle of postnatal day-7 Sprague Dawley rats. Ventricle size, heme oxygenase-1 (HO-1) expression, and the presence of iron were evaluated 24 and 72 hours after injection. A subset of animals was treated with an iron chelator (deferoxamine) or vehicle for 24 hours after hemoglobin injection, and ventricle size and cell death were evaluated.Intraventricular injection of hemoglobin and iron resulted in ventricular enlargement at 24 hours compared with the injection of aCSF. Protoporphyrin IX, the iron-deficient immediate heme precursor, did not result in ventricular enlargement after injection into the ventricle. HO-1, the enzyme that releases iron from heme, was increased in the hippocampus and cortex of hemoglobin-injected animals at 24 hours compared with aCSF-injected controls. Treatment with an iron chelator, deferoxamine, decreased hemoglobin-induced ventricular enlargement and cell death.Intraventricular injection of hemoglobin and iron can induce hydrocephalus. Treatment with an iron chelator reduced hemoglobin-induced ventricular enlargement. This has implications for the pathogenesis and treatment of posthemorrhagic hydrocephalus.aCSF, artificial cerebrospinal fluidDAB, 3,3'-diaminobenzidine-4HClGMH-IVH, germinal matrix hemorrhage/intraventricular hemorrhageHO-1, heme oxygenase-1ICH, intracerebral hemorrhagePBS, phosphate-buffered salineSVZ, subventricular zoneTBST, tris-buffered saline with Tween 20.

  View details for DOI 10.1227/NEU.0000000000000524

  View details for Web of Science ID 000345431600033

  View details for PubMedID 25121790

  View details for PubMedCentralID PMC4237659

• OUTCOMES OF PEDIATRIC BRAINSTEM LOW GRADE GLIOMAS: A SINGLE INSTITUTION SERIES Upadhyaya, S., Muraszko, K., Garton, H., Maher, C., Robertson, P. OXFORD UNIV PRESS INC. 2014

  View details for DOI 10.1093/neuonc/nou253.32

  View details for Web of Science ID 000350452200290

• Stent-assisted coil embolization of a symptomatic middle cerebral artery aneurysm in an infant JOURNAL OF NEUROSURGERY-PEDIATRICS Savastano, L. E., Chaudhary, N., Gemmete, J. J., Garton, H. L., Maher, C. O., Pandey, A. S. 2014; 14 (5): 550-554

  Abstract

  Pediatric intracranial aneurysms are rare and challenging to treat. Achieving efficacy and durability of aneurysmal occlusion while maintaining parent vessel patency requires innovative treatment strategies, especially in cases in which aneurysmal location or morphology pose substantial morbidity associated with microsurgical treatment. In the last 3 decades, endovascular treatments have had a remarkable evolution and are currently considered safe and effective therapeutic options for cerebral aneurysms. While endovascular techniques are well described in the English literature, the endovascular management of pediatric aneurysms continues to pose a challenge. In this report, the authors describe the case of a 9-month-old infant who presented with a 1-day history of acute-onset left-sided hemiparesis and left facial droop. Imaging revealed a large symptomatic saccular middle cerebral artery aneurysm. Treatment included successful stent-assisted aneurysm coiling. At follow-up, the patient continued to fare well and MR angiography confirmed complete occlusion of the aneurysm dome. This case features the youngest patient in the English literature to harbor an intracranial aneurysm successfully treated with stent-assisted coiling. Based on this experience, endovascular intervention with vascular reconstruction can be safe and effective for the treatment of infants and could further improve prognosis; however, further studies are necessary to confirm these findings.

  View details for DOI 10.3171/2014.7.PEDS1449

  View details for Web of Science ID 000343531000017

  View details for PubMedID 25171722

• Differences in vascular endothelial growth factor receptor expression and correlation with the degree of enhancement in medulloblastoma JOURNAL OF NEUROSURGERY-PEDIATRICS Hervey-Jumper, S. L., Garton, H. L., Lau, D., Altshuler, D., Quint, D. J., Robertson, P. L., Muraszko, K. M., Maher, C. O. 2014; 14 (2): 121-128

  Abstract

  Vascular endothelial growth factor (VEGF) is the major proangiogenic factor in many solid tumors. Vascular endothelial growth factor receptor (VEGFR) is expressed in abundance in pediatric patients with medulloblastoma and is associated with tumor metastasis, poor prognosis, and proliferation. Gadolinium enhancement on MRI has been suggested to have prognostic significance for some tumors. The association of VEGF/VEGFR and Gd enhancement in medulloblastoma has never been closely examined. The authors therefore sought to evaluate whether Gd-enhancing medulloblastomas have higher levels of VEGFR and CD31. Outcomes and survival in patients with enhancing and nonenhancing tumors were also compared.A retrospective analysis of patients with enhancing, nonenhancing, and partially enhancing medulloblastomas was performed. Primary end points included risk stratification, extent of resection, and perioperative complications. A cohort of 3 enhancing and 3 nonenhancing tumors was selected for VEGFR and CD31 analysis as well as microvessel density measurements.Fifty-eight patients were analyzed, and 20.7% of the medulloblastomas in these patients were nonenhancing. Enhancing medulloblastomas exhibited strong VEGFR1/2 and CD31 expression relative to nonenhancing tumors. There was no significant difference in perioperative complications or patient survival between the 2 groups.These results suggest that in patients with medulloblastoma the presence of enhancement on MRI may correlate with increased vascularity and angiogenesis, but does not correlate with worse patient prognosis in the short or long term.

  View details for DOI 10.3171/2014.4.PEDS13244

  View details for Web of Science ID 000339472900001

  View details for PubMedID 24905841

• Subdural hygromas and arachnoid cysts RESPONSE JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O. 2014; 13 (5): 584-585

  View details for Web of Science ID 000334903700018

  View details for PubMedID 24910863

• Efficacy of antibiotic-impregnated external ventricular drains in reducing ventriculostomy-associated infections JOURNAL OF CLINICAL NEUROSCIENCE Mikhaylov, Y., Wilson, T. J., Rajajee, V., Thompson, B. G., Maher, C. O., Sullivan, S. E., Jacobs, T. L., Kocan, M. J., Pandey, A. S. 2014; 21 (5): 765-768

  Abstract

  Use of an external ventricular drain (EVD) is essential for managing patients with hydrocephalus or intracranial hypertension. While this procedure is safe and efficacious, ventriculostomy-associated infections (VAI) continue to cause significant morbidity. In this study, we evaluated the efficacy of antibiotic-coated EVD (AC-EVD) in reducing the occurrence of VAI. Between July 2007 and July 2009, 203 patients underwent placement of an EVD. A total of 145 of these patients met the inclusion criteria, with 76 patients (52.4%) receiving AC-EVD and 69 patients (47.6%) receiving uncoated EVD. Ten patients (6.9%) developed VAI, of whom three were in the AC-EVD group and seven were in the uncoated EVD group (p=0.19). The mean duration between catheter insertion and positive cerebrospinal fluid culture was significantly greater in the AC-EVD group versus the uncoated EVD group (15±4days versus 4±2days, respectively; p=0.001). In the uncoated EVD group, 17 of 69 patients (24.6%) were dead at 3years versus 12 of 76 (15.8%) patients in the AC-EVD group (p=0.21). The overall VAI rate was 6.9% with a trend toward lower infection rates in the AC-EVD group compared to the uncoated EVD group (3.9% versus 10.1%, respectively; p>0.05).

  View details for DOI 10.1016/j.jocn.2013.09.002

  View details for Web of Science ID 000335805500011

  View details for PubMedID 24411330

• Filum terminale lipomas: imaging prevalence, natural history, and conus position JOURNAL OF NEUROSURGERY-PEDIATRICS Cools, M. J., Al-Holou, W. N., Stetler, W. R., Wilson, T. J., Muraszko, K. M., Ibrahim, M., La Marca, F., Garton, H. J., Maher, C. O. 2014; 13 (5): 559-567

  Abstract

  Filum terminale lipomas (FTLs) are being identified with increasing frequency due to the increasing utilization of MRI. Although an FTL may be associated with tethered cord syndrome (TCS), in many cases FTLs are diagnosed incidentally in patients without any symptoms of TCS. The natural history of FTLs is not well defined.The authors searched the clinical and imaging records at a single institution over a 14-year interval to identify patients with FTLs. For patients with an FTL, the clinical records were reviewed for indication for imaging, presenting symptoms, perceived need for surgery, and clinical outcome. A natural history analysis was performed using all patients with more than 6 months of clinical follow-up.A total of 436 patients with FTL were identified. There were 217 males and 219 females. Of these patients, 282 (65%) were adults and 154 (35%) were children. Symptoms of TCS were present in 22 patients (5%). Fifty-two patients underwent surgery for FTL (12%). Sixty-four patients (15%) had a low-lying conus and 21 (5%) had a syrinx. The natural history analysis included 249 patients with a mean follow-up time of 3.5 years. In the follow-up period, only 1 patient developed new symptoms.Filum terminale lipomas are a common incidental finding on spinal MRI, and most patients present without associated symptoms. The untreated natural history is generally benign for asymptomatic patients.

  View details for DOI 10.3171/2014.2.PEDS13528

  View details for Web of Science ID 000334903700013

  View details for PubMedID 24628511

• Malignant Cause of Ventriculoperitoneal Shunt 'Pseudocyst': A Case Report PEDIATRIC NEUROSURGERY Awori, J., Wu, C. Y., Maher, C. O. 2014; 50 (2): 73-75

  Abstract

  Abdominal pseudocysts are an uncommon complication of ventriculoperitoneal (VP) shunts. We present the case of a 4-year-old boy with a history of complicated hydrocephalus managed with a VP shunt due to sequelae of prematurity. The patient presented with abdominal distention, and a pseudocyst was diagnosed. Despite shunt externalization and aspiration, the pseudocyst continued to produce up to 1 liter of serosanguineous fluid per day. After MRI revealed malignant features within the pseudocyst, laparotomy was performed and the pseudocyst was partially excised. Pathology reports suggested sarcoma. The cystic mass grew back aggressively, accompanied by distant metastasis. The patient's condition deteriorated and he died from his disease. To our knowledge, this represents the first report of an abdominal malignancy mimicking a pseudocyst and causing VP shunt failure.

  View details for DOI 10.1159/000377731

  View details for Web of Science ID 000355932100004

  View details for PubMedID 25832495

• Diagnosis and management of residual and recurrent cerebral aneurysms which have previously been coiled Surgical Endovascular Neuroradiology Pandey , A., Thompson , B., Maher , C., Chaudhary , N., Elias , A., Gemmete , J. Prestigiacamo C Thieme. 2014
• Pediatric Neurosurgery Current Diagnosis and Treatment: Surgery Song , D., Maher , C., Muraszko , K. McGraw Hill. 2014; 14th ed.
• Stroke in Children Pediatric Neurosurgery: Tricks of the Trade Maher , C. Cohen AR (ed.) Thieme. 2014
• The Role of CD133+Cells in a Recurrent Embryonal Tumor with Abundant Neuropil and True Rosettes (ETANTR) BRAIN PATHOLOGY Hervey-Jumper, S. L., Altshuler, D. B., Wang, A. C., He, X., Maher, C. O., Robertson, P. L., Garton, H. L., Fan, X., Muraszko, K. M., Camelo-Piragua, S. 2014; 24 (1): 45-51

  Abstract

  Embryonal tumor with abundant neuropil and true rosettes (ETANTR) is a recently described embryonal neoplasm of the central nervous system, consisting of a well-circumscribed embryonal tumor of infancy with mixed features of ependymoblastoma (multilayer ependymoblastic rosettes and pseudorosettes) and neuroblastoma (neuroblastic rosettes) in the presence of neuropil-like islands. We present the case of a young child with a very aggressive tumor that rapidly recurred after gross total resection, chemotherapy and radiation. Prominent vascular sclerosis and circumscribed tumor led to the diagnosis of malignant astroblastoma; however, rapid recurrence and progression of this large tumor after gross total resection prompted review of the original pathology. ETANTR is histologically distinct with focal glial fibrillary acid protein (GFAP) and synaptophysin expression in the presence of neuronal and ependymoblastic rosettes with focal neuropil islands. These architectural features, combined with unique chromosome 19q13.42 amplification, confirmed the diagnosis. In this report, we describe tumor stem cell (TSC) marker CD133, CD15 and nestin alterations in ETANTR before and after chemotherapy. We found that TSC marker CD133 was richly expressed after chemotherapy in recurrent ETANTR, while CD15 is depleted compared with that expressed in the original tumor, suggesting that CD133+ cells likely survived initial treatment, further contributing to formation of the recurrent tumor.

  View details for DOI 10.1111/bpa.12079

  View details for Web of Science ID 000328618900005

  View details for PubMedID 23865520

  View details for PubMedCentralID PMC3867594

• Management of subdural hygromas associated with arachnoid cysts Clinical article JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O., Garton, H. L., AL-Holou, W. N., Trobe, J. D., Muraszko, K. M., Jackson, E. M. 2013; 12 (5): 434-443

  Abstract

  Arachnoid cysts may occasionally be associated with subdural hygromas. The management of these concurrent findings is controversial.The authors reviewed their experience with arachnoid cysts and identified 8 patients with intracranial arachnoid cysts and an associated subdural hygroma. The medical records and images for these patients were also examined.In total, 8 patients presented with concurrent subdural hygroma and arachnoid cyst. Of these 8 patients, 6 presented with headaches and 4 had nausea and vomiting. Six patients had a history of trauma. One patient was treated surgically at the time of initial presentation, and 7 patients were managed without surgery. All patients experienced complete resolution of their presenting signs and symptoms.Subdural hygroma may lead to symptomatic presentation for otherwise asymptomatic arachnoid cysts. The natural course of cyst-associated subdural hygromas, even when symptomatic, is generally benign, and symptom resolution can be expected in most cases. The authors suggest that symptomatic hygroma is not an absolute indication for surgical treatment and that expectant management can result in good outcomes in many cases.

  View details for DOI 10.3171/2013.8.PEDS13206

  View details for Web of Science ID 000325956400004

  View details for PubMedID 24011368

• Hemangiomas and propranolol JOURNAL OF NEUROSURGERY-PEDIATRICS Strahle, J., Odden, A. J., Maher, C. O., Garton, H. L. 2013; 12 (4): 418

  View details for DOI 10.3171/2013.6.PEDS13284

  View details for Web of Science ID 000324964600022

  View details for PubMedID 23952032

• Distribution of cerebellar tonsil position: implications for understanding Chiari malformation Clinical article JOURNAL OF NEUROSURGERY Smith, B. W., Strahle, J., Bapuraj, J., Muraszko, K. M., Garton, H. L., Maher, C. O. 2013; 119 (3): 812-819

  Abstract

  Prior attempts to define normal cerebellar tonsil position have been limited by small numbers of patients precluding analysis of normal distribution by age group. The authors' objective in the present study was to analyze cerebellar tonsil location in every age range.Two thousand four hundred patients were randomly selected from a database of 62,533 consecutive patients undergoing MRI and were organized into 8 age groups. Magnetic resonance images were directly examined for tonsil location, morphology, and other features. Patients with a history or imaging findings of posterior fossa abnormalities unrelated to Chiari malformation (CM) were excluded from analysis. The caudal extent of the cerebellar tonsils was measured at the midsagittal and lowest parasagittal positions.The mean tonsil height decreased slightly with advancing age into young adulthood and increased with advancing age in the adult age range. An increasing age in the adult age range was associated with a decreased likelihood of a tonsil position 5 mm or more below the foramen magnum (p = 0.0004). In general, the lowest tonsil position in each age group was normally distributed. Patients with pegged morphology were more likely to have a tonsil location at least 5 mm below the foramen magnum (85%), as compared with those having intermediate (38%) or rounded (2%) morphology (p < 0.0001). Female sex was associated with a lower mean tonsil position (p < 0.0001). Patients with a lower tonsil position also tended to have an asymmetrical tonsil position, usually lower on the right (p < 0.0001).Cerebellar tonsil position follows an essentially normal distribution and varies significantly by age. This finding has implications for advancing our understanding of CM.

  View details for DOI 10.3171/2013.5.JNS121825

  View details for Web of Science ID 000323358700040

  View details for PubMedID 23767890

• Cerebellar tonsil position and Chiari malformation Response JOURNAL OF NEUROSURGERY Maher, C. O. 2013; 119 (3): 811

  View details for Web of Science ID 000323358700039

  View details for PubMedID 24137803

• Macrovascular decompression of the median nerve for posttraumatic neuralgic limb pain JOURNAL OF NEUROSURGERY-PEDIATRICS Pabaney, A., Hervey-Jumper, S. L., Domino, J., Maher, C. O., Yang, L. S. 2013; 12 (3): 270-273

  Abstract

  Neuropathic pain is rare in children, and few reports provide adequate guidelines for treatment. The authors describe the successful treatment of tardy neuropathic pain via macrovascular decompression in a 15-year-old boy who presented with progressive pain 11 years following trauma to the upper extremity that had required surgical repair of the brachial artery. Examination revealed mild chronic median and ulnar motor neuropathy as well as recent progressive lancinating pain and a Tinel sign at the prior scar. A soft tissue mass in the neurovascular bundle at the site of previous injury was noted on MRI. Surgical exploration demonstrated an altered anatomical relationship of the previously repaired brachial artery and the median nerve, resulting in pulsatile compression of the median nerve by the brachial artery. Neurolysis and decompression of the median nerve with physical separation from the brachial artery resulted in immediate pain relief. This is the first report of macrovascular decompression of a major peripheral nerve with complete symptom resolution. Noninvasive imaging together with a thorough history and physical examination can support identification of this potential etiology of peripheral neuralgic pain. Recognition and treatment of this uncommon problem may yield improved outcomes for children with neuropathic pain.

  View details for DOI 10.3171/2013.6.PEDS12471

  View details for Web of Science ID 000323358800013

  View details for PubMedID 23829379

• Incidental Findings in Children With Blunt Head Trauma Evaluated With Cranial CT Scans PEDIATRICS Rogers, A. J., Maher, C. O., Schunk, J. E., Quayle, K., Jacobs, E., Lichenstein, R., Powell, E., Miskin, M., Dayan, P., Holmes, J. F., Kuppermann, N., Pediat Emergency Care Appl Res 2013; 132 (2): E356-E363

  Abstract

  Cranial computed tomography (CT) scans are frequently obtained in the evaluation of blunt head trauma in children. These scans may detect unexpected incidental findings. The objectives of this study were to determine the prevalence and significance of incidental findings on cranial CT scans in children evaluated for blunt head trauma.This was a secondary analysis of a multicenter study of pediatric blunt head trauma. Patients <18 years of age with blunt head trauma were eligible, with those undergoing cranial CT scan included in this substudy. Patients with coagulopathies, ventricular shunts, known previous brain surgery or abnormalities were excluded. We abstracted radiology reports for nontraumatic findings. We reviewed and categorized findings by their clinical urgency.Of the 43,904 head-injured children enrolled in the parent study, 15,831 underwent CT scans, and these latter patients serve as the study cohort. On 670 of these scans, nontraumatic findings were identified, with 16 excluded due to previously known abnormalities or surgeries. The remaining 654 represent a 4% prevalence of incidental findings. Of these, 195 (30%), representing 1% of the overall sample, warranted immediate intervention or outpatient follow-up.A small but important number of children evaluated with CT scans after blunt head trauma had incidental findings. Physicians who order cranial CTs must be prepared to interpret incidental findings, communicate with families, and ensure appropriate follow-up. There are ethical implications and potential health impacts of informing patients about incidental findings.

  View details for DOI 10.1542/peds.2013-0299

  View details for Web of Science ID 000322957300006

  View details for PubMedID 23878053

• Prasugrel is effective and safe for neurointerventional procedures JOURNAL OF NEUROINTERVENTIONAL SURGERY Stetler, W. R., Chaudhary, N., Thompson, B., Gemmete, J. J., Maher, C. O., Pandey, A. S. 2013; 5 (4): 332-336

  Abstract

  Clopidogrel bisulfate and aspirin are routinely administered as dual antiplatelet agents for many neurointerventional procedures, especially for intravascular stent placement. Many patients are non-responsive to clopidogrel, either secondary to drug interactions or from variations of cytochrome P450 enzymes. Prasugrel (brand name Effient, Eli Lilly and Company, Indianapolis, IN, USA) is a new antiplatelet agent that has been utilized extensively in patients undergoing cardiovascular procedures but its safety and efficacy during neurointerventional procedures have not been evaluated.To examine whether prasugrel is a safe and effective alternative to clopidogrel for neurointerventional procedures, especially in those patients who are either non-responders or allergic to clopidogrel.The medical records of all patients undergoing neurointerventional procedures at our institution who received prasugrel between January 2009 and July 2011 were retrospectively reviewed. A systematic chart review was performed and the following data were recorded: demographics, aneurysm location, endovascular techniques, peri- and post-procedural complications, hemorrhagic complications, clinical outcome and angiographic outcome.16 patients undergoing neurointerventional procedures received prasugrel over a 2 year interval. All patients who had follow-up studies of P2Y12 inhibition had immediate therapeutic response to prasugrel. There were no complications related to ischemic or intracranial hemorrhage.Prasugrel is a viable alternative to clopidogrel for patients undergoing neurointerventional procedures who are non-responders to clopidogrel. Further study is needed to evaluate the safety, efficacy and cost-effectiveness of prasugrel compared with clopidogrel for patients undergoing neurointerventional procedures.

  View details for DOI 10.1136/neurintsurg-2012-010302

  View details for Web of Science ID 000320744500015

  View details for PubMedID 22619468

• Prevalence and natural history of arachnoid cysts in adults JOURNAL OF NEUROSURGERY Al-Holou, W. N., Terman, S., Kilburg, C., Garton, H. L., Muraszko, K. M., Maher, C. O. 2013; 118 (2): 222-231

  Abstract

  Arachnoid cysts are a frequent finding on intracranial imaging. The prevalence and natural history of these cysts in adults are not well defined.We retrospectively reviewed the electronic medical records of a consecutive series of adults who underwent brain MRI over a 12-year interval to identify those with arachnoid cysts. The MRI studies were reviewed to confirm the diagnosis. For those patients with arachnoid cysts, we evaluated presenting symptoms, cyst size, and cyst location. Patients with more than 6 months' clinical and imaging follow-up were included in a natural history analysis.A total of 48,417 patients underwent brain MRI over the study period. Arachnoid cysts were identified in 661 patients (1.4%). Men had a higher prevalence than women (p < 0.0001). Multiple arachnoid cysts occurred in 30 patients. The most common locations were middle fossa (34%), retrocerebellar (33%), and convexity (14%). Middle fossa cysts were predominantly left-sided (70%, p < 0.001). Thirty-five patients were considered symptomatic and 24 underwent surgical treatment. Sellar and suprasellar cysts were more likely to be considered symptomatic (p < 0.0001). Middle fossa cysts were less likely to be considered symptomatic (p = 0.01. The criteria for natural history analysis were met in 203 patients with a total of 213 cysts. After a mean follow-up of 3.8 ± 2.8 years (for this subgroup), 5 cysts (2.3%) increased in size and 2 cysts decreased in size (0.9%). Only 2 patients developed new or worsening symptoms over the follow-up period.Arachnoid cysts are a common incidental finding on intracranial imaging in all age groups. Although arachnoid cysts are symptomatic in a small number of patients, they are associated with a benign natural history for those presenting without symptoms.

  View details for DOI 10.3171/2012.10.JNS12548

  View details for Web of Science ID 000313937900002

  View details for PubMedID 23140149

• Moyamoya Syndrome Associated with Hemoglobin Southampton (Casper) PEDIATRIC NEUROSURGERY Delavari, N., Strahle, J., Maher, C. O. 2013; 49 (5): 307-310

  Abstract

  When moyamoya vasculopathy results from an associated disease, this vasculopathy is then referred to as moyamoya syndrome. Moyamoya syndrome has been reported in association with sickle cell disease, neurofibromatosis type 1, Down syndrome, radiation exposure, and other predisposing factors. Other than sickle cell disease, rare hemoglobinopathies, such as hemoglobin Fairfax and hemoglobin Alesha, have been reported to occur with moyamoya. We present a case of moyamoya syndrome associated with an unstable hemoglobinopathy, hemoglobin Southampton (Casper). This is the first reported case of moyamoya associated with this hemoglobinopathy.

  View details for DOI 10.1159/000367973

  View details for Web of Science ID 000345450800009

  View details for PubMedID 25342087

• Microsurgical and endovascular treatment of anterior circulation aneurysms Neurovascular Surgical Techniques Pandey , A., Elias , A., Maher , C., Thompson , B., Chaudhary , N., Gemmete , J. Jabbour PM (ed.) Jaypee Medical Publishing. 2013: 129-147
• Natural History of Chiari Malformation The Chiari Malformations Maher , C. Tubbs RS, Oakes J (eds.) Springer. 2013: 227-239
• Effect of Amusement Park Rides on Programmable Shunt Valve Settings PEDIATRIC NEUROSURGERY Strahle, J., Collins, K., Stetler, W. R., Smith, B. W., Garton, T., Garton, C., Garton, H. L., Maher, C. O. 2013; 49 (1): 21-23

  Abstract

  Magnetically programmable shunt valves are susceptible to environmental factors including magnetic fields and accelerative forces. It is unknown if rollercoasters with or without magnetic brakes or linear induction motors (LIMs) are capable of altering the setting of a programmable shunt valve.Two different valve types (type A, n = 10; type B, n = 9) were tested at varying resistance settings in 2 trials on 6 different amusement park rides including 2 rides with LIMs, 2 rides with magnetic brakes, and 2 rides without magnetic technology.The performance level of valve type A and the setting of valve type B changed on rollercoasters with magnets (A = 2.5% [2/80]; B = 5.6% [4/72]) and without magnets (A = 7.5% [3/40]; B = 2.8% [1/36]). Neither valve setting changed when exposed to a Ferris wheel or during ambulation throughout the park.Magnetically programmable valves are susceptible to changes in pressure settings when exposed to amusement park rides with elevated vertical gravitational forces, irrespective of the presence of LIMs or magnetic brakes.

  View details for DOI 10.1159/000355247

  View details for Web of Science ID 000329054300004

  View details for PubMedID 24192584

• Diffuse Pontine Lesions in Children with Neurofibromatosis Type 1: Making a Case for Unidentified Bright Objects PEDIATRIC NEUROSURGERY Hervey-Jumper, S. L., Singla, N., Gebarski, S. S., Robertson, P., Maher, C. O. 2013; 49 (1): 55-59

  Abstract

  Using an illustrative case of a presumed pontine unidentified bright object (UBO) with spontaneous lesion regression over 2 years, we review the importance of including UBOs in the differential diagnosis of children with confirmed or possible neurofibromatosis type 1 (NF1) who present with diffuse pontine enlargement and T2-weighted changes on MRI. Asymptomatic children with presumed NF1 and diffuse pontine lesions should not be treated with radiation and should not be biopsied. Prior reports of good prognosis associated with pontine glioma in patients with NF1 may have been unrecognized UBOs in some cases.

  View details for DOI 10.1159/000355417

  View details for Web of Science ID 000329054300011

  View details for PubMedID 24192157

• Initial experience with a combined multidetector CT and biplane digital subtraction angiography suite with a single interactive table for the diagnosis and treatment of neurovascular disease JOURNAL OF NEUROINTERVENTIONAL SURGERY Gemmete, J. J., Chaudhary, N., Pandey, A. S., Oweis, Y., Thompson, B., Maher, C. O., Gandhi, D., Ansari, S. A. 2013; 5 (1): 73-80

  Abstract

  A combined imaging suite is useful in the diagnosis and treatment of vascular disease involving the head and neck. This study demonstrates the utility of a multidetector row CT and biplane digital subtraction angiography (DSA) system (hybrid suite) with a single interactive table for the evaluation and treatment of neurovascular disease.30 patients were studied utilizing the hybrid suite. Direct intra-arterial and selective intravenous injection of contrast with CT imaging (IA-CTA and IV-CTV) was performed in nine vascular tumors, three intracranial arteriovenous malformations, four spinal vascular lesions, one aneurysm and two inferior petrosal sinus sampling cases. Angiography with CT perfusion (CTP) imaging was obtained in five temporary balloon occlusion tests, two ischemic stroke and two vasospasm cases. A CT scan of the head was obtained in two cases during aneurysm coiling. The value of the IA-CTA and IV-CTV images compared with conventional CT and MRI images was qualitatively assessed.All studies were technically successful with no complications. IA-CTA and IV-CTV were useful in the diagnosis and treatment of vascular disease. All IA-CTA and IV-CTV images were qualitatively graded as superior to conventional imaging. CTP imaging provided information about the penumbra and area of infarction in five temporary balloon test occlusions, two ischemic stroke and two vasospasm cases. A CT scan of the head provided timely information in two aneurysm coiling cases. The hybrid suite allowed angiography and CT scanning to be performed immediately without patient transfer.This hybrid suite improves the diagnostic and therapeutic capabilities of treating a multitude of neurovascular diseases.

  View details for DOI 10.1136/neurintsurg-2011-010092

  View details for Web of Science ID 000313133600015

  View details for PubMedID 21990532

• Outcomes of Tethered Cord Repair With a Layered Soft Tissue Closure ANNALS OF PLASTIC SURGERY Levi, B., Sugg, K. B., Lien, S. C., Kasten, S. J., Muraszko, K. M., Maher, C. O., Buchman, S. R. 2013; 70 (1): 74-78

  Abstract

  Previous studies have demonstrated the benefit of releasing symptomatic tethered cords; however, complications such as seroma, cerebrospinal fluid leak, and infection continue to plague these patients. We propose that composite tissue closure of tethered cord repairs yields superior outcomes and that a collaborative effort between neurosurgery and plastic surgery may result in enhanced structural and functional results.This is a retrospective study comprised of consecutive patients with tethered cord syndrome by 2 neurosurgeons and 2 plastic surgeons between 1994 and 2008 at a single institution. All consecutive patients who underwent tethered cord release by neurosurgery and subsequent composite tissue closure with fascial and musculofascial flaps by plastic surgery were included. Data were collected by retrospective chart review and analyzed using parametric methods.A total of 86 consecutive patients were included in this study, with follow-up ranged from 12 to 144 months (average follow-up, 29 months). There were no statistical differences in follow-up time, comorbidities, or surgeon when comparing hospital readmission or reoperation. There was no statistical difference in complications when comparing the different flap closures. We had a 1.2% infection rate, a 4.7% readmission rate, and a 3.5% reoperation rate.We believe that local soft tissue rearrangement improves the closure by providing an additional layer of vascularized tissue between the skin and the spinal cord. We believe our series represents a significant sample size compared with those previously reported for an experience that achieves multilayered soft tissue closure after tethered cord repair. Our results support the idea that neurosurgeons should consider consultation of plastic surgeons when treating patients with tethered cord syndrome surgically.

  View details for DOI 10.1097/SAP.0b013e31822f9ada

  View details for Web of Science ID 000312487400018

  View details for PubMedID 21921789

• Cervical Arterial Injury After Blunt Trauma in Children: Characterization and Advanced Imaging JOURNAL OF PEDIATRIC ORTHOPAEDICS Tolhurst, S. R., Vanderhave, K. L., Caird, M. S., Garton, H. L., Graziano, G. P., Maher, C. O., Hensinger, R. N., Farley, F. A. 2013; 33 (1): 37-42

  Abstract

  The incidence of cervical vascular injury (CVI) after blunt cervical trauma in children and adolescents is low. Potential harm from missed injury is high. Screening for CVI has increased with advances in noninvasive angiography, including computed tomographic angiography (CTA) and magnetic resonance angiography (MRA). We attempt to characterize CVI in children and adolescents and evaluate the utility of advanced imaging in CVI screening in this patient population.Clinical and radiographic records of consecutive patients aged 4 to 18 years with blunt cervical spine trauma from 1998 to 2008 were reviewed. Patient demographics, injury pattern, neurological findings, and treatment were recorded.Sixty-one patients were identified. Nineteen underwent screening to evaluate for CVI, including 12 males and 7 females, mean age 13.5 years. The most common mechanism of injury was motor vehicle collision (n=11). Seven patients underwent MRA, 7 CTA, 3 had both studies, and 2 had traditional angiography. Seven patients had CVI, with an overall incidence of 11.5%. High-risk criteria (fracture extension to transverse foramina, fracture/dislocations or severe subluxations, or C1-C3 injury) were associated with increased rates of CVI. Neurological injury was found in 12/19 patients screened and 6/7 patients with CVI. Two of 7 patients underwent anticoagulation due to documented CVI. No delayed-onset ischemic neurological events occurred.After blunt cervical spine trauma, certain fracture patterns increase the risk of CVI. CVI is common, with a minimum incidence of 7/61 or >10% of pediatric patients with blunt cervical spine injury. Over 1/4 of patients studied on the basis of high-risk criteria had injury. Advanced imaging with noninvasive angiography (CTA/MRA) should be strongly considered in pediatric patients with cervical spine trauma. The presence of CVI may prompt a change in management.Level IV-retrospective diagnostic study.

  View details for DOI 10.1097/BPO.0b013e3182670392

  View details for Web of Science ID 000312256100009

  View details for PubMedID 23232377

• Is Insurance Status a Modifiable Factor in Brain Tumor Treatment Outcomes? ARCHIVES OF SURGERY Hervey-Jumper, S. L., Maher, C. O. 2012; 147 (11): 1025

  View details for DOI 10.1001/archsurg.2012.1493

  View details for Web of Science ID 000312397400008

  View details for PubMedID 23165617

• Programmable shunt valve affected by exposure to a tablet computer Laboratory investigation JOURNAL OF NEUROSURGERY-PEDIATRICS Strahle, J., Selzer, B. J., Muraszko, K. M., Garton, H. L., Maher, C. O. 2012; 10 (2): 118-120

  Abstract

  The authors investigated the effect of a tablet computer on performance-level settings of a programmable shunt valve.Magnetic field strength near the tablet computer with and without a cover was recorded at distances between 0 and 100 mm. Programmable valves were exposed to the tablet device at distances of less than 1 cm, 1-2.5 cm, 2.5-5 cm, 5-10 cm, and greater than 10 cm. For each distance tested, the valves were exposed 100 times to the tablet with the cover, resulting in 500 total valve exposures. The tablet alone, without the cover, was also tested at distances of less than 1 cm for 30 valve exposures. Changes in valve performance-level settings were recorded.The maximum recorded magnetic flux density of a tablet with a cover was 17.0 mT, and the maximum recorded magnetic flux density of the tablet alone was 7.6 mT. In 100 exposures at distances between 0 and 1 cm, 58% of valves had different settings following exposure. At distances greater than 1 cm but less than 2.5 cm, 5% of valves in 100 exposures had setting changes. Only a single setting change was noted in 100 exposures at distances greater than 2.5 cm but less than 5 cm. No setting changes were noted at distances greater than 5 cm, including 100 exposures between 5 and 10 cm, and 100 exposures of more than 10 cm. For the 30 valve exposures to the tablet without a cover, 20 valve performance-level changes (67%) were noted.Based on these results, exposure to tablet devices may alter programmable shunt valve settings.

  View details for DOI 10.3171/2012.3.PEDS1211

  View details for Web of Science ID 000306767000009

  View details for PubMedID 22734456

• Mechanisms of Hydrocephalus After Neonatal and Adult Intraventricular Hemorrhage TRANSLATIONAL STROKE RESEARCH Strahle, J., Garton, H. L., Maher, C. O., Muraszko, K. M., Keep, R. F., Xi, G. 2012; 3: S25-S38

  Abstract

  Intraventricular hemorrhage (IVH) is a cause of significant morbidity and mortality and is an independent predictor of a worse outcome in intracerebral hemorrhage (ICH) and germinal matrix hemorrhage (GMH). IVH may result in both injuries to the brain as well as hydrocephalus. This paper reviews evidence on the mechanisms and potential treatments for IVH-induced hydrocephalus. One frequently cited theory to explain hydrocephalus after IVH involves obliteration of the arachnoid villi by microthrombi with subsequent inflammation and fibrosis causing CSF outflow obstruction. Although there is some evidence to support this theory, there may be other mechanisms involved, which contribute to the development of hydrocephalus. It is also unclear whether the causes of acute and chronic hydrocephalus after hemorrhage occur via different mechanisms; mechanical obstruction by blood in the former, and inflammation and fibrosis in the latter. Management of IVH and strategies for prevention of brain injury and hydrocephalus are areas requiring further study. A better understanding of the pathogenesis of hydrocephalus after IVH, may lead to improved strategies to prevent and treat post-hemorrhagic hydrocephalus.

  View details for DOI 10.1007/s12975-012-0182-9

  View details for Web of Science ID 000305436500005

  View details for PubMedID 23976902

  View details for PubMedCentralID PMC3750748

• Natural history and imaging prevalence of cavernous malformations in children and young adults Clinical article JOURNAL OF NEUROSURGERY-PEDIATRICS Al-Holou, W. N., O'Lynnger, T. M., Pandey, A. S., Gemmete, J. J., Thompson, B., Muraszko, K. M., Garton, H. L., Maher, C. O. 2012; 9 (2): 198-205

  Abstract

  This study was undertaken to define the age-related prevalence of cavernous malformations (CMs) in children and young adults undergoing intracranial imaging. In addition, the authors aim to clarify the natural history of CMs in young people, especially in those with incidentally discovered lesions.To identify those patients with CMs, the authors retrospectively reviewed the electronic medical records of 14,936 consecutive patients 25 years of age or younger who had undergone brain MR imaging. In patients with a CM, clinical and imaging data were collected. Patients with untreated cavernomas who had more than 6 months of clinical and MR imaging follow-up were included in a natural history analysis. The natural history analysis included 110 CMs in 56 patients with a 3.5-year mean clinical follow-up interval (199 patient-years and 361 cavernoma-years).In 92 patients (0.6%), 164 CMs were identified. The imaging prevalence of cavernomas increased with advancing age (p = 0.002). Multiple CMs occurred in 28 patients (30%), and 8 patients (9%) had a family history of multiple CMs. Fifty patients (54%) presented with symptoms related to the cavernoma, of whom 30 presented with hemorrhage (33%). Of the 164 cavernomas identified, 103 (63%) were considered incidental, asymptomatic lesions. Larger size was associated with acute symptomatic presentation (p = 0.0001). During the follow-up interval, 6 patients with 8 cavernomas developed 11 symptomatic hemorrhages after initial identification. Five of the patients who had a hemorrhage during the follow-up interval had initially presented with hemorrhage, while only 1 had presented incidentally. The hemorrhage rate for all patients in the natural history group was 1.6% per patient-year and 0.9% per cavernoma-year. The hemorrhage rate was 8.0% per patient-year in the symptomatic group versus 0.2% in the incidental group. Symptomatic hemorrhage after long-term follow-up was associated with initial acute presentation (p = 0.02).The imaging prevalence of CM increases with advancing age during childhood. Patients presenting without hemorrhage have a significantly lower risk of bleeding compared with those who present with acute neurological symptoms. Comparing this series of children to prior analyses of CM natural history in adults, the authors' data do not suggest a higher bleeding risk in younger patients.

  View details for DOI 10.3171/2011.11.PEDS11390

  View details for Web of Science ID 000299583200016

  View details for PubMedID 22295927

• Spontaneous resolution of an infantile hemangioma in a dorsal root ganglion NEUROSURGICAL FOCUS Hervey-Jumper, S. L., McKeever, P. E., Gebarski, S. S., Muraszko, K. M., Maher, C. O. 2011; 31 (6): E16

  Abstract

  Infantile hemangiomas are tumors commonly seen in children. Few authors have reported infantile hemangiomas affecting the CNS, and there are no prior reports detailing spontaneous resolution of a histologically proven juvenile hemangioma within a dorsal root ganglion. The authors report the case of a newborn boy with a large cutaneous hemangioma in the midline of his back. Spinal MR images were obtained to rule out associated spinal cord tethering, and an intradural spinal lesion was unexpectedly discovered. Biopsy revealed an intradural infantile hemangioma within the dorsal root ganglion, and, based on this diagnosis, no resection was performed. Sixteen months following the biopsy, the cutaneous hemangioma had become involuted and the intradural hemangioma had completely resolved. The behavior of the intradural component in this case follows the natural history of many cutaneous infantile hemangiomas.

  View details for DOI 10.3171/2011.9.FOCUS11203

  View details for Web of Science ID 000297743200018

  View details for PubMedID 22133174

• Incidental findings on cranial imaging in nonagenarians NEUROSURGICAL FOCUS Al-Holou, W. N., Khan, A., Wilson, T. J., Stetler, W. R., Shah, G. V., Maher, C. O. 2011; 31 (6)

  Abstract

  The aim of this article was to report on the nature and prevalence of incidental imaging findings in a consecutive series of patients older than 90 years of age who underwent intracranial imaging for any reason.The authors retrospectively reviewed the electronic medical and imaging records of consecutive patients who underwent brain MR imaging at a single institution over a 153-month interval and were at least 90 but less than 100 years of age at the time of the imaging study. The prevalence of lesions by type in this consecutive series of MR imaging evaluations was calculated for all patients. The authors reviewed the medical record to evaluate whether a change in management was recommended based on MR imaging findings. They evaluated patient age at the time of death and the time interval between MR imaging and death.The authors identified 177 patients who met the study criteria. The group included 119 women (67%) and 58 (33%) men. Their mean age was 92.3 ± 1.8 years. Evidence of acute ischemic changes or cerebrovascular accident (CVA) was found in 36 patients (20%). Fifteen patients (8%) had an intracranial tumor. Intracranial aneurysms were incidentally identified in 6 patients (3%). Chronic subdural hematomas were found in 3 patients (2%). Overall, 25 patients (14%) had some change in medical management as a result of the MR imaging findings. The most common MR imaging finding that resulted in a change in medical management was an acute CVA (p < 0.0001). The mean time to death from date of MR imaging was 2.5 ± 2.3 years.Intracranial imaging is rarely performed in patients older than 90 years. In cases of suspected stroke, MR imaging findings may influence treatment decisions. Brain MR imaging studies ordered for other indications in this age group rarely influence treatment decisions. Incidentally discovered lesions in this age group are generally not treated.

  View details for DOI 10.3171/2011.9.FOCUS11205

  View details for Web of Science ID 000297743200013

  View details for PubMedID 22133167

• Tarlov cysts: a controversial lesion of the sacral spine NEUROSURGICAL FOCUS Lucantoni, C., Than, K. D., Wang, A. C., Valdivia-Valdivia, J. M., Maher, C. O., La Marca, F., Park, P. 2011; 31 (6): E14

  Abstract

  The primary aim of our study was to provide a comprehensive review of the clinical, imaging, and histopathological features of Tarlov cysts (TCs) and to report operative and nonoperative management strategies in patients with sacral TCs. A literature review was performed to identify articles that reported surgical and nonsurgical management of TCs over the last 10 years. Tarlov cysts are often incidental lesions found in the spine and do not require surgical intervention in the great majority of cases. When TCs are symptomatic, the typical clinical presentation includes back pain, coccyx pain, low radicular pain, bowel/bladder dysfunction, leg weakness, and sexual dysfunction. Tarlov cysts may be revealed by MR and CT imaging of the lumbosacral spine and must be meticulously differentiated from other overlapping spinal pathological entities. They are typically benign, asymptomatic lesions that can simply be monitored. To date, no consensus exists about the best surgical strategy to use when indicated. The authors report and discuss various surgical strategies including posterior decompression, cyst wall resection, CT-guided needle aspiration with intralesional fibrin injection, and shunting. In operative patients, the rates of short-term and long-term improvement in clinical symptoms are not clear. Although neurological deficit frequently improves after surgical treatment of TC, pain is less likely to do so.

  View details for DOI 10.3171/2011.9.FOCUS11221

  View details for Web of Science ID 000297743200016

  View details for PubMedID 22133181

• Patient with Chiari malformation Type I presenting with inducible hemifacial weakness Case report JOURNAL OF NEUROSURGERY-PEDIATRICS Witt, C. E., Wang, A. C., Maher, C. O., Than, K. D., Garton, H. L., Muraszko, K. M. 2011; 8 (6): 620-624

  Abstract

  In this report, the authors describe the first known case of inducible hemifacial weakness in a patient with Chiari malformation Type I (CM-I). The patient was a 14-year-old girl with a 1-year history of right facial paresis induced by sustained leftward head rotation. These episodes were characterized by weak activation of her right facial muscles with preserved eye opening and closure. Additionally, she had hypernasal speech, persistent headaches, and intermittent left arm twitching. Magnetic resonance imaging demonstrated a CM-I. A suboccipital craniectomy and C-1 laminectomy were performed for decompression of the CM-I, with duraplasty and coagulation of the pial surface of the cerebellar tonsils. At the 9-month follow-up, the patient's inducible hemifacial weakness had completely resolved. Her symptoms were thought to have resulted from the CM-I, perhaps due to traction on the right facial nerve by the ectopic tonsils with head rotation.

  View details for DOI 10.3171/2011.9.PEDS11309

  View details for Web of Science ID 000297450200016

  View details for PubMedID 22132921

• Incidentally discovered lesions Introduction NEUROSURGICAL FOCUS Maher, C. O., Klimo, P., Smith, E. R. 2011; 31 (6): 1 p preceding E1

  View details for DOI 10.3171/2011.10.FOCUS11269

  View details for Web of Science ID 000297743200001

  View details for PubMedID 22133175

• Prevalence and natural history of pineal cysts in adults Clinical article JOURNAL OF NEUROSURGERY Al-Holou, W. N., Terman, S. W., Kilburg, C., Garton, H. L., Muraszko, K. M., Chandler, W. F., Ibrahim, M., Maher, C. O. 2011; 115 (6): 1106-1114

  Abstract

  We reviewed our experience with pineal cysts to define the natural history and clinical relevance of this common intracranial finding.The study population consisted of 48,417 consecutive patients who underwent brain MR imaging at a single institution over a 12-year interval and who were over 18 years of age at the time of imaging. Patient characteristics, including demographic data and other intracranial diagnoses, were collected from cases involving patients with a pineal cyst. We then identified all patients with pineal cysts who had been clinically evaluated at our institution and who had at least 6 months of clinical and imaging follow-up. All inclusion criteria for the natural history analysis were met in 151 patients.Pineal cysts measuring 5 mm or larger in greatest dimension were found in 478 patients (1.0%). Of these, 162 patients were male and 316 were female. On follow-up MR imaging of 151 patients with pineal cyst at a mean interval of 3.4 years from the initial study, 124 pineal cysts remained stable, 4 increased in size, and 23 decreased in size. Cysts that were larger at the time of initial diagnosis were more likely to decrease in size over the follow-up interval (p = 0.004). Patient sex, patient age at diagnosis, and the presence of septations within the cyst were not significantly associated with cyst change on follow-up.Follow-up imaging and neurosurgical evaluation are not mandatory for adults with asymptomatic pineal cysts.

  View details for DOI 10.3171/2011.6.JNS11506

  View details for Web of Science ID 000297450700007

  View details for PubMedID 21780858

• Spontaneous intracranial hemorrhage and multiple intracranial aneurysms in a patient with Roberts/SC phocomelia syndrome JOURNAL OF NEUROSURGERY-PEDIATRICS Wang, A. C., Gemmete, J. J., Keegan, C. E., Witt, C. E., Muraszko, K. M., Than, K. D., Maher, C. O. 2011; 8 (5): 460-463

  Abstract

  Roberts/SC phocomelia syndrome (RBS) is a rare but distinct genetic disorder with an autosomal recessive inheritance pattern. It has been associated with microcephaly, craniofacial malformation, cavernous hemangioma, encephalocele, and hydrocephalus. There are no previously reported cases of RBS with intracranial aneurysms. The authors report on a patient with a history of RBS who presented with a spontaneous posterior fossa hemorrhage. Multiple small intracranial aneurysms were noted on a preoperative CT angiogram. The patient underwent emergency craniotomy for evacuation of the hemorrhage. A postoperative angiogram confirmed the presence of multiple, distal small intracranial aneurysms.

  View details for DOI 10.3171/2011.8.PEDS11117

  View details for Web of Science ID 000296379100007

  View details for PubMedID 22044369

• Pineal cysts RESPONSE JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O., Garton, H. L., Muraszko, K. M. 2011; 8 (4): 422

  View details for Web of Science ID 000295301800019

• Benign sacrococcygeal teratoma with spinal canal invasion and paraplegia JOURNAL OF PEDIATRIC SURGERY Kunisaki, S. M., Maher, C. O., Powelson, I., Gemmete, J. J., Hirschl, R. B., Mychaliska, G. B. 2011; 46 (9): E1-E4

  Abstract

  Sacrococcygeal teratomas can have a wide variety of clinical presentations depending on their size, vascularity, and degree of mass effect upon adjacent structures. Intradural invasion of a sacrococcygeal teratoma is a rare variant that has generally been associated with a favorable neurologic outcome. In this report, we present the case of a neonate with paraplegia secondary to a large Altman type III sacrococcygeal teratoma with extension into the spinal canal. The neoplasm was completely removed using a combined anterior and posterior approach after preoperative embolization of the lateral sacral arteries. Pathology showed a mature teratoma. The patient remains paraplegic without evidence of tumor recurrence at 1 year of age.

  View details for DOI 10.1016/j.jpedsurg.2011.05.013

  View details for Web of Science ID 000295461900001

  View details for PubMedID 21929968

• Chiari malformation associated with craniosynostosis NEUROSURGICAL FOCUS Strahle, J., Muraszko, K. M., Buchman, S. R., Kapurch, J., Garton, H. L., Maher, C. O. 2011; 31 (3): E2

  Abstract

  Chiari malformation (CM) Type I is frequently associated with craniosynostosis. Optimal management of CM in patients with craniosynostosis is not well-established. The goal of this study was to report on a series of pediatric patients with both craniosynostosis and CM and discuss their management.The authors searched the medical records of 383 consecutive patients treated for craniosynostosis at a single institution over a 15-year period to identify those with CM. They recorded demographic data as well as surgical treatment and outcomes for these patients. When MR imaging was performed, cerebellar tonsillar descent was recorded and any other associated findings, such as hydrocephalus or spinal syringes, were noted.A total of 29 patients with both CM and craniosynostosis were identified. Of these cases, 28% had associated occipital venous abnormalities, 45% were syndromic, and 52% also had hydrocephalus. Chiari malformation was more likely to be present in those patients with isolated lambdoid synostosis (55%), multisuture synostosis (35%), and pansynostosis (80%), compared with patients with coronal synostosis (6%) or sagittal synostosis (3%). All patients underwent surgical repair of craniosynostosis: 16 had craniosynostosis repair as well as CM decompression, and 13 patients did not undergo CM decompression. Of the 7 patients in whom craniosynostosis repair alone was performed, 5 had decreased tonsillar ectopia postoperatively and 5 had improved CSF flow studies postoperatively. Both patients with a spinal syrinx had imaging-documented syrinx regression after craniosynostosis repair. In 12 patients in whom CM was diagnosed after primary craniosynostosis repair, 5 had multiple cranial vault expansions and evidence of elevated intracranial pressure. In 5 cases, de novo CM development was documented following craniosynostosis repair at a mean of 3.5 years after surgery.Chiari malformation is frequently seen in patients with both multi- and single-suture lambdoid craniosynostosis. Chiari malformation, and even a spinal cord syrinx, will occasionally resolve following craniofacial repair. De novo development of CM after craniosynostosis repair is not unusual.

  View details for DOI 10.3171/2011.6.FOCUS11107

  View details for Web of Science ID 000294767400003

  View details for PubMedID 21882907

• Neurosurgical Management of Congenital Malformations of the Brain NEUROIMAGING CLINICS OF NORTH AMERICA Hervey-Jumper, S. L., Cohen-Gadol, A. A., Maher, C. O. 2011; 21 (3): 705-+

  Abstract

  Congenital malformations encompass a diverse group of disorders that often present at birth, either as the result of genetic abnormalities, infection, errors of morphogenesis, or abnormalities in the intrauterine environment. Congenital disorders affecting the brain are now often diagnosed before delivery with the use of prenatal ultrasonography. Over the past several decades, there have been major advances in the understanding and management of these conditions. This review focuses on the most common cranial congenital malformations, limiting the discussion to the neurosurgically relevant aspects of arachnoid cysts, pineal cysts, Chiari malformations, and encephaloceles.

  View details for DOI 10.1016/j.nic.2011.05.008

  View details for Web of Science ID 000294372000013

  View details for PubMedID 21807319

• Neurosurgical Management of Congenital Malformations and Inherited Disease of the Spine NEUROIMAGING CLINICS OF NORTH AMERICA Hervey-Jumper, S. L., Garton, H. L., Wetjen, N. M., Maher, C. O. 2011; 21 (3): 719-+

  Abstract

  Congenital malformations encompass a diverse group of disorders present at birth as result of genetic abnormalities, infection, errors of morphogenesis, or abnormalities in the intrauterine environment. Congenital disorders affecting the brain and spinal cord are often diagnosed before delivery with the use of prenatal ultrasonography and maternal serum screening. Over the past several decades there have been major advances in the understanding and management of these conditions. This article focuses on the most common spinal congenital malformations.

  View details for DOI 10.1016/j.nic.2011.05.009

  View details for Web of Science ID 000294372000014

  View details for PubMedID 21807320

• Subtotal Excision With Adjunctive Sclerosing Therapy for the Treatment of Severe Symptomatic Orbital Lymphangiomas ARCHIVES OF OPHTHALMOLOGY Kahana, A., Bohnsack, B. L., Cho, R. I., Maher, C. O. 2011; 129 (8): 1073-1076

  Abstract

  Orbital lymphangiomas are congenital malformations with abnormal and dead-end lymphatic channels and present management challenges to ophthalmologists and orbital surgeons. Recurrent hemorrhage and expansion can lead to vision loss and disfigurement. We report our technique that uses adjunctive intraoperative injection of sodium morrhuate, 5%, under direct visualization into lymphangioma channels prior to excision. We believe that in the hands of experienced orbital surgeons, and with appropriate preoperative evaluation and careful surgical technique, this procedure is useful in saving vision and avoiding complications from orbital lymphangiomas.

  View details for DOI 10.1001/archophthalmol.2011.204

  View details for Web of Science ID 000293648800015

  View details for PubMedID 21825192

  View details for PubMedCentralID PMC3434690

• Natural history of Chiari malformation Type I following decision for conservative treatment Clinical article JOURNAL OF NEUROSURGERY-PEDIATRICS Strahle, J., Muraszko, K. M., Kapurch, J., Bapuraj, J., Garton, H. L., Maher, C. O. 2011; 8 (2): 214-221

  Abstract

  The natural history of the Chiari malformation Type I (CM-I) is incompletely understood. The authors report on the outcome of a large group of patients with CM-I that were initially selected for nonsurgical management.The authors identified 147 patients in whom CM-I was diagnosed on MR imaging, who were not offered surgery at the time of diagnosis, and in whom at least 1 year of clinical and MR imaging follow-up was available after the initial CM-I diagnosis. These patients were included in an outcome analysis.Patients were followed clinically and by MR imaging for a mean duration of 4.6 and 3.8 years, respectively. Of the 147 patients, 9 had new symptoms attributed to the CM-I during the follow-up interval. During this time, development of a spinal cord syrinx occurred in 8 patients; 5 of these patients had a prior diagnosis of a presyrinx state or a dilated central canal. Spontaneous resolution of a syrinx occurred in 3 patients. Multiple CSF flow studies were obtained in 74 patients. Of these patients, 23 had improvement in CSF flow, 39 had no change, and 12 showed worsening CSF flow at the foramen magnum. There was no significant change in the mean amount of cerebellar tonsillar herniation over the follow-up period. Fourteen patients underwent surgical treatment for CM-I. There were no differences in initial cerebellar tonsillar herniation or CSF flow at the foramen magnum in those who ultimately underwent surgery compared with those who did not.In patients with CM-Is that are selected for nonsurgical management, the natural history is usually benign, although spontaneous improvement and worsening are occasionally seen.

  View details for DOI 10.3171/2011.5.PEDS1122

  View details for Web of Science ID 000293144900017

  View details for PubMedID 21806365

• The effect of age on arteriovenous malformations in children and young adults undergoing magnetic resonance imaging CHILDS NERVOUS SYSTEM O'Lynnger, T. M., Al-Holou, W. N., Gemmete, J. J., Pandey, A. S., Thompson, B., Garton, H. L., Maher, C. O. 2011; 27 (8): 1273-1279

  Abstract

  Arteriovenous malformations (AVMs) are the most frequently encountered structural cause of spontaneous intracerebral hemorrhage in childhood, excluding hemorrhages of prematurity. The goal of our study was to examine the relationship between age and AVM prevalence on imaging in children, which to date has not been well described.We queried the electronic and radiographic records of 14,936 consecutive patients aged 25 years or less who had undergone brain magnetic resonance imaging (MRI) at a single institution over an 11-year period to identify those with a cerebral AVM. We collected age, gender, and other demographic characteristics for all patients. For all patients with a cerebral AVM, we recorded the location, size, drainage pattern, Spetzler-Martin grade, medical history, and presence of neurological symptoms.Cerebral AVMs were identified in 55 patients (0.37%). The prevalence of AVMs detected on MRI significantly increased with age (p = 0.001). AVMs were found in 0.34% of boys (25 of 7,447) and 0.40% of girls (30 of 7,489). AVMs were most commonly identified in the frontal lobes (36%), followed by parietal (20%) and temporal lobes (13%). Sixty percent (n = 33) of AVMs were less than 3 cm in size, 35% (n = 19) were 3-6 cm in size, and 5.5% (n = 3) were greater than 6 cm in size. As for Spetzler-Martin grade of the AVMs, 25.5% were grade I, 18.2% were grade II, 36.4% were grade III, 16.4% were grade IV, and 3.6% were grade V.AVMs are seen more frequently on MRI with advancing age in children and young adults.

  View details for DOI 10.1007/s00381-011-1434-9

  View details for Web of Science ID 000293020300016

  View details for PubMedID 21442267

• Chiari malformation Type I and syrinx in children undergoing magnetic resonance imaging Clinical article JOURNAL OF NEUROSURGERY-PEDIATRICS Strahle, J., Muraszko, K. M., Kapurch, J., Bapuraj, J., Garton, H. L., Maher, C. O. 2011; 8 (2): 205-213

  Abstract

  Chiari malformation Type I (CM-I) with an associated spinal syrinx is a common pediatric diagnosis. A better understanding of the relative age-related prevalence and MR imaging characteristics of these associated conditions may lead to improved treatment decisions.The authors performed a retrospective review of 14,116 consecutive individuals 18 years of age or younger who had undergone brain or cervical spine MR imaging at the University of Michigan between November 1997 and August 2008. In the patients with CM-I, demographic, clinical, and radiographic information was recorded.Five hundred nine children (3.6%) with CM-I were identified. Among these patients, 23% also had a spinal cord syrinx, and 86% of the syringes were found in the cervical spine. The MR imaging prevalence of CM-I with a syrinx was 1.2% in girls and 0.5% in boys (p < 0.0001). The severity of impaired CSF flow at the foramen magnum was associated with the amount of tonsillar herniation (p < 0.0001) and conformation of the tonsils (p < 0.0001). Patients with CM-I were treated surgically in 35% of cases; these patients exhibited more severe tonsillar herniation (p < 0.0001) and impaired CSF flow (p < 0.0001) as compared with those who did not undergo surgery. On imaging, 32% of all the patients with CM-I were considered symptomatic by the treating physician. Patients were more likely to be considered symptomatic if they were female, had a syrinx, displayed abnormal tonsillar pulsations, or had a greater amount of tonsillar herniation.In this study the authors describe the age-related prevalence and MR imaging characteristics of CM-I and its association with a syrinx and other abnormalities in a large group of children who underwent MR imaging for any indication. Syringes are more common in older children, in girls, and in patients with a greater degree of tonsillar descent and CSF flow impairment.

  View details for DOI 10.3171/2011.5.PEDS1121

  View details for Web of Science ID 000293144900016

  View details for PubMedID 21806364

• Neurological complications of extracorporeal membrane oxygenation in children Clinical article JOURNAL OF NEUROSURGERY-PEDIATRICS Hervey-Jumper, S. L., Annich, G. M., Yancon, A. R., Garton, H. L., Muraszko, K. M., Maher, C. O. 2011; 7 (4): 338-344

  Abstract

  Extracorporeal membrane oxygenation (ECMO) is a potentially life-saving treatment for patients in refractory cardiorespiratory failure. Neurological complications that result from ECMO treatment are known to significantly impact patient survival and quality of life. The purpose of this study was to review the incidence of neurological complications of ECMO in the pediatric population and the role of neurosurgery in the treatment of these patients.Data were obtained from the national Extracorporeal Life Support Organization (ELSO) Registry for the years 1990 to 2009. The neurological complications recorded by the registry include CNS hemorrhage, CNS infarction, and seizure. The ECMO Registry at the authors' institution was then searched, and 3 pediatric patients who had undergone craniotomy during ECMO treatment were identified.Children in the ELSO Registry who were treated with ECMO survived to hospital discharge in 65% of cases. Intracranial hemorrhage occurred in 7.4% of the ECMO-treated patients, with 36% of those surviving to hospital discharge. Hemorrhage was more likely in patients younger than 30 days old and in those requiring ECMO for cardiac indications. Cerebral infarction occurred in 5.7% of all ECMO-treated patients. Clinically diagnosed seizures occurred in 8.4% of all ECMO-treated patients. The ECMO Registry at the authors' institution revealed that 1898 patients were treated there. Intracranial hemorrhage was diagnosed in 81 patients (5.8%), and 3 of these patients were treated with craniotomy. Two of the patients were alive with minimal neurological impairment and normal school performance at 10 and 16 years of follow-up.Intracranial hemorrhage is a serious complication of ECMO treatment. While the surgical risk is substantial, there may be a role for surgical evacuation of hemorrhage in well-selected patients.

  View details for DOI 10.3171/2011.1.PEDS10443

  View details for Web of Science ID 000288726000004

  View details for PubMedID 21456903

• Long-Term Health Status in Benign External Hydrocephalus PEDIATRIC NEUROSURGERY Yew, A. Y., Maher, C. O., Muraszko, K. M., Garton, H. L. 2011; 47 (1): 1-6

  Abstract

  Benign external hydrocephalus (BEH) is characterized by excess cerebrospinal fluid in the frontal subarachnoid spaces in infants evaluated for macrocephaly. We sought to describe the natural history of this disorder, specifically its clinical presentation, disease course and long-term health status impact using the validated, disease-specific Hydrocephalus Outcome Questionnaire (HOQ).An inception cohort of children >5 and <18 years old, with a history of BEH was assembled by ICD-9 and a key word search of medical and radiology records. Review confirmed the diagnosis of BEH, excluded major medical comorbidities and assessed presentation, radiographic features and head size/growth velocity. The HOQ was administered by mail.We identified 99 patients, 5-12 years old (55% males). Twenty were born prematurely, 12 with <33 weeks gestation. Children presented at an average age of 9 ± 4.8 months (mean ± SD). The presenting complaint was macrocephaly in 65 cases. Other presenting findings were positional head shape deformity and torticollis; 10% had a family history of macrocephaly. Developmental delay was present in 21% of patients (4% verbal, 20% gross motor, 4% fine motor delay). Four patients had small subdural hematomas, none with suspicion of a non-accidental trauma. During clinical reassessment over a mean follow-up of 13 months, the average head percentile was stable and none of the patients developed new subdural hematomas. Gross motor delay resolved in 15/20 and fine motor delay in 4/4 patients. Verbal delay resolved in 2/4 patients, but interestingly, was newly detected in 6 other children. None of the patients required cerebrospinal fluid shunting. The response rate to the HOQ was 25% (median age 7 years, 74% females). The average overall HOQ score was 0.75 ± 0.24 versus 0.68 ± 0.19 for a previously published cohort of shunted hydrocephalic children.BEH patients in this series generally saw resolution of presenting motor developmental delays; however, new verbal delays were detected in a non-trivial number of patients. Quality of life measurements suggest some reduction in health status, but less so than is seen with shunted hydrocephalus.

  View details for DOI 10.1159/000322357

  View details for Web of Science ID 000294947900001

  View details for PubMedID 21778677

• The effectiveness of ventriculocystocisternostomy for suprasellar arachnoid cysts Clinical article JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O., Goumnerova, L. 2011; 7 (1): 64-72

  Abstract

  The aim of this study was to report the long-term outcomes of patients receiving endoscopic ventriculocystocisternostomy (VCC) for suprasellar arachnoid cysts (SACs), and to analyze all published reports on outcomes of ventriculocystostomy (VC) versus VCC to compare the effectiveness of the 2 techniques.Eleven consecutive patients with previously untreated SACs were surgically treated using endoscopic VCC. Another 2 patients were treated with VCC following ventriculoperitoneal shunt placement. Clinical imaging data were recorded. An analysis was performed of all published patient outcomes following endoscopic VC or VCC for an SAC.Developmental delay and progressive macrocephaly were the most common preoperative symptoms. At a mean clinical follow-up interval of 63 months, 10 of 11 patients undergoing primary VCC did not require reoperation. An analysis of the literature suggests that VCC may be more effective than VC. Of the 44 reported patients that underwent VC as a first treatment, 7 (16%) required reoperation, and 7 (8%) of 86 patients who underwent VCC as a first treatment required reoperation. When VC or VCC was performed following a prior surgical procedure, 4 of 11 patients undergoing VC had a treatment failure requiring reoperation. In contrast, only 2 of the 17 reported cases of VCC following a prior procedure required further treatment. The difference in reoperation rates following either primary or secondary VC was significantly higher than following primary or secondary VCC (p = 0.04).The authors conclude that VCC is an effective and durable treatment for symptomatic SACs in most cases.

  View details for DOI 10.3171/2010.10.PEDS10356

  View details for Web of Science ID 000285669600014

  View details for PubMedID 21194289

• Harvey Cushing's experience with cranial deformity NEUROSURGICAL FOCUS Maher, C. O., Buchman, S. R., O'Hara, E., Cohen-Gadol, A. A. 2010; 29 (6): E6

  Abstract

  Surgery for cranial deformity was associated with significant surgical morbidity during the early part of the 20th century. For this reason, Harvey Cushing was initially not in favor of surgical treatment of craniosynostosis. Later in his career, Cushing began to operate on these children, although it never became a major focus of his practice. Several examples of his patients with cranial deformity are presented, and his limited role in the development of this field is discussed.

  View details for DOI 10.3171/2010.9.FOCUS10191

  View details for Web of Science ID 000285648900007

  View details for PubMedID 21121720

• Local and regional flap closure in myelomeningocele repair: a 15-year review CHILDS NERVOUS SYSTEM Lien, S. C., Maher, C. O., Garton, H. L., Kasten, S. J., Muraszko, K. M., Buchman, S. R. 2010; 26 (8): 1091-1095

  Abstract

  A trend in large myelomeningocele defect repair involves soft tissue closure with muscle and fascial flap techniques to provide a durable, protective, and tension-free soft tissue covering. We propose that composite tissue closure yields superior outcomes regardless of defect size.We present a retrospective review of our 15-year, single-institution experience using this approach. Our study includes 45 consecutive patients treated using combinations of muscle and fascia flaps for primary closure of a myelomeningocele defect.Lumbosacral fascia closures were used in 18 cases (40%) with paraspinous muscle closure and 12 cases (27%) without paraspinous closure. Fascial closure with bony pedicle periosteum and gluteal muscle and fascial closure were used in four cases (9%) each. Other techniques included latissimus dorsi flaps and combinations of these techniques. Postoperatively, none of our patients experienced a cerebrospinal fluid leak, and only one patient required reoperation for skin flap necrosis.Objective measures show that universal application of flap techniques may lead to better outcomes for soft tissue closure during myelomeningocele repair.

  View details for DOI 10.1007/s00381-010-1099-9

  View details for Web of Science ID 000280060900018

  View details for PubMedID 20195618

• Pediatric and Inherited Neurovascular Diseases NEUROSURGERY CLINICS OF NORTH AMERICA Vanaman, M. J., Hervey-Jumper, S. L., Maher, C. O. 2010; 21 (3): 427-+

  Abstract

  Pediatric and inherited neurovascular syndromes have diverse presentations and treatments. Although many of these diseases are uncommon, they must be included in the differential diagnosis for children with strokes or hemorrhages. In neurosurgical practice, familial cavernous malformations, hereditary hemorrhagic telangiectasia (HHT), and moyamoya are the most frequently encountered of these diseases. In this article, we will discuss familial cavernomas and HHT, as well as more unusual entities such as PHACE(S) syndrome, Klippel-Trenaunay syndrome, Wyburn-Mason syndrome, sinus pericranii, radiation-induced vasculopathy, and blue rubber bleb nevus (BRBN) syndrome. Moyamoya disease is covered in several other articles in this volume.

  View details for DOI 10.1016/j.nec.2010.03.001

  View details for Web of Science ID 000279583700003

  View details for PubMedID 20561493

• Spinal Cord Vascular Malformations in Children NEUROSURGERY CLINICS OF NORTH AMERICA Song, D., Garton, H. L., Fahim, D. K., Maher, C. O. 2010; 21 (3): 503-+

  Abstract

  Spinal vascular malformations comprise a diverse group of abnormalities, including arteriovenous malformations (AVMs), cavernous malformations, dural arteriovenous fistulas (AVFs), and capillary telangiectasias. These conditions each have distinct causes, presentations, radiologic appearances, and natural histories. This article explores the presentation, natural history, investigation, and treatment of spinal AVMs, spinal AVFs, and spinal cavernous malformations.

  View details for DOI 10.1016/j.nec.2010.03.004

  View details for Web of Science ID 000279583700009

  View details for PubMedID 20561499

• Introduction to Pediatric Vascular Neurosurgery Preface NEUROSURGERY CLINICS OF NORTH AMERICA Klimo, P., Maher, C. O., Smith, E. R. 2010; 21 (3): XIII-XIV

  View details for DOI 10.1016/j.nec.2010.03.014

  View details for Web of Science ID 000279583700001

  View details for PubMedID 20561491

• Surgery for extratemporal nonlesional epilepsy in children: a meta-analysis CHILDS NERVOUS SYSTEM Ansari, S. F., Maher, C. O., Tubbs, R., Terry, C. L., Cohen-Gadol, A. A. 2010; 26 (7): 945-951

  Abstract

  Previous small studies have demonstrated that seizure outcomes following surgery for extratemporal lobe epilepsy (ETLE) in children are worse than those for temporal lobe epilepsy. We have conducted a meta-analysis of the available literature to better understand ETLE surgical outcomes in children.We searched PubMed (1990-2009) for appropriate studies using the following terms: ETLE, ETLE surgery, ETLE surgery outcome, frontal lobe epilepsy, occipital lobe epilepsy, and parietal lobe epilepsy. Our collected data included patient age at seizure onset and surgery, the cerebral lobe involved with epileptogenesis, MRI findings, predominant seizure semiology, intracranial monitoring use (electrode implantation), epileptic region histopathology, and postoperative seizure outcome. Statistical analysis was performed to determine associations among these variables and postoperative outcome.Ninety-five patients from 17 studies satisfied the inclusion criteria. Pathological findings (p = 0.039) and seizure type (p = 0.025) were significantly associated with outcome: A larger proportion of patients with cortical dysplasia and complex partial seizures experienced better outcomes. Age at surgery (p = 0.073) and the cerebral resection site (p = 0.059) were marginally associated with seizure outcome.This study confirms previous reports: Surgical outcomes for ETLE epilepsy are significantly worse than those for temporal lobe epilepsy. The reasons for this difference may include the diffuse nature of the pathology involved in ETLE, difficulty in localizing the seizure focus in young children, and involvement of "eloquent" nonresectable cortex in epileptogenesis. Because of the reporting variability among different epilepsy centers, more uniform protocols are necessary for fair evaluation and comparison of outcomes among the different centers.

  View details for DOI 10.1007/s00381-009-1056-7

  View details for Web of Science ID 000278577800014

  View details for PubMedID 20013124

• Prevalence and natural history of arachnoid cysts in children Clinical article JOURNAL OF NEUROSURGERY-PEDIATRICS Al-Holou, W. N., Yew, A. Y., Boomsaad, Z. E., Garton, H. L., Muraszko, K. M., Maher, C. O. 2010; 5 (6): 578-585

  Abstract

  Arachnoid cysts are a frequent finding on intracranial imaging in children. The prevalence and natural history of these cysts are not well defined. The authors studied a large consecutive series of children undergoing MR imaging to better define both the MR imaging-demonstrated prevalence and behavior of these lesions over time.The authors reviewed a consecutive series of 11,738 patients who were 18 years of age or younger and had undergone brain MR imaging at a single institution during an 11-year period. In the patients in whom intracranial arachnoid cysts were identified, clinical and demographic information was recorded and imaging characteristics, such as cyst size and location, were evaluated. Prevalence data were analyzed using univariate and multivariate logistic regression, linear regression, and ANOVA. All patients with sufficient data (repeat MR imaging studies as well as repeated clinical evaluation over at least 5 months) for a natural history analysis were identified. This group was assessed for any change in symptoms or imaging appearance during the follow-up interval.Three hundred nine arachnoid cysts (2.6% prevalence rate) were identified. There was an increased prevalence of arachnoid cysts in males (p < 0.000001). One hundred eleven patients met all criteria for inclusion in the natural history analysis. After a mean follow-up of 3.5 years, 11 arachnoid cysts increased in size, 13 decreased, and 87 remained stable. A younger age at presentation was significantly associated with cyst enlargement (p = 0.001) and the need for surgery (p = 0.05). No patient older than 4 years of age at the time of initial diagnosis had cyst enlargement, demonstrated new symptoms, or underwent surgical treatment.Arachnoid cysts are a common incidental finding on intracranial imaging in pediatric patients. An older age at the time of presentation is associated with a lack of clinical or imaging changes over time.

  View details for DOI 10.3171/2010.2.PEDS09464

  View details for Web of Science ID 000278024200008

  View details for PubMedID 20515330

• Cerebrospinal fluid leak with recurrent meningitis following tonsillectomy Case report JOURNAL OF NEUROSURGERY-PEDIATRICS Hervey-Jumper, S. L., Ghori, A. K., Quint, D. J., Marentette, L. J., Maher, C. O. 2010; 5 (3): 302-305

  Abstract

  The authors report an unusual case of bilateral large petrous apex cephaloceles in a 14-year-old boy with a history of recurrent meningitis. Although these lesions are rare and usually asymptomatic, surgical correction is recommended if they are associated with a persistent CSF leak. In this patient, the extensive bilateral cranial defects were not adequately treated by an intracranial approach alone. Repair of a defect in the posterior pharyngeal wall, the site of a prior tonsillectomy, ultimately resulted in repair of the CSF fistula.

  View details for DOI 10.3171/2009.10.PEDS09336

  View details for Web of Science ID 000275085800014

  View details for PubMedID 20192650

• The natural history of pineal cysts in children and young adults Clinical article JOURNAL OF NEUROSURGERY-PEDIATRICS Al-Holou, W. N., Maher, C. O., Muraszko, K. M., Garton, H. L. 2010; 5 (2): 162-166

  Abstract

  The authors reviewed their experience with pediatric pineal cysts to define the natural history and clinical relevance of this common intracranial finding.The authors identified all patients with pineal cysts who had been clinically evaluated at their institution over an 11.5-year interval and were < 25 years of age at the time of diagnosis. All inclusion criteria were met in 106 patients, and included repeated MR imaging as well as repeated clinical evaluation over at least a 6-month interval.The mean age at diagnosis was 11.7 +/- 7.2 years. Forty-two patients were male and 64 were female. On follow-up MR imaging evaluation at a mean interval of 3.0 years from the initial study, 98 pineal cysts had no increase in size and no change in imaging appearance. Six pineal cysts increased in size and 2 others had a change in imaging characteristics without associated growth. Younger age was associated with cyst change or growth on follow-up imaging (p = 0.02). The mean age of patients with cysts that changed or grew was 5.5 years, and the mean age of patients with stable pineal cysts was 12.2 years. Initial cyst size and appearance on MR imaging were not significant predictors of growth or change in imaging appearance at follow-up. Similarly, the patient's sex was not a significant predictor of growth or change in imaging characteristics.Follow-up imaging and neurosurgical evaluation may be considered optional in older children with pineal cysts.

  View details for DOI 10.3171/2009.9.PEDS09297

  View details for Web of Science ID 000274069100004

  View details for PubMedID 20121364

• Primary Diffuse Leptomeningeal Oligodendroglioma PEDIATRIC NEUROSURGERY Hervey-Jumper, S. L., Jumper, M., Blaivas, M., Parmar, H. A., Robertson, P. L., Maher, C. O. 2010; 46 (4): 326-328

  View details for DOI 10.1159/000317261

  View details for Web of Science ID 000289557500015

  View details for PubMedID 21196802

• Removal of Ventricular Shunts PEDIATRIC NEUROSURGERY Al-Holou, W. N., Sack, J. A., Garton, H. L., Muraszko, K. M., Maher, C. O. 2010; 46 (3): 172-176

  Abstract

  Although most patients with an implanted ventriculoperitoneal shunt device will require cerebrospinal fluid diversion over the course of their lifetime, there appears to be a small number of patients that are shunt independent and may benefit from shunt removal.We retrospectively analyzed 661 patients with hydrocephalus treated over a 10-year period at a single institution. In 10 patients, a systematic shunt weaning protocol was attempted before removal of the cerebrospinal fluid shunt.Ten patients underwent an attempt at shunt removal. Seven of these patients were successfully weaned and 3 were not. The indications to attempt shunt removal for the 7 patients that were successfully weaned were recurrent complications and infections requiring multiple shunt externalizations and revisions in 4 patients, asymptomatic shunt disconnection in 2 patients, and symptomatic overdrainage in 1 patient. None of the patients that were successfully weaned had a history of shunt failure resulting in ventriculomegaly. Two of the 3 patients who failed shunt weaning attempts had a history of shunt failure that resulted in ventriculomegaly.A small number of patients with shunted hydrocephalus may benefit from removal of their shunt.

  View details for DOI 10.1159/000321921

  View details for Web of Science ID 000284161200004

  View details for PubMedID 20962548

• Distal revision of ventriculoperitoneal shunts using a peel-away sheath Technical note JOURNAL OF NEUROSURGERY-PEDIATRICS Tubbs, R., Maher, C. O., Young, R. L., Cohen-Gadol, A. A. 2009; 4 (4): 402-405

  Abstract

  The authors describe a new technique for revision of an occluded distal ventriculoperitoneal shunt catheter that obviates the need for laparotomy or trocar insertion into the peritoneal cavity. The authors review their early experience with 34 patients suffering from a distal ventriculoperitoneal shunt failure and treated with this technique. There were no incidents of intraabdominal injury or wound complications. In 2 patients conversion to a minilaparotomy was required for safe placement of the shunt. Proper peritoneal placement was confirmed with abdominal radiographs in all cases. This technique has been safe and effective and may be considered an alternative to traditional laparotomy or laparoscopic methods.

  View details for DOI 10.3171/2009.5.PEDS09152

  View details for Web of Science ID 000270519400020

  View details for PubMedID 19795975

• Urological outcome following multiple repeat spinal cord untethering operations JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O., Bauer, S. B., Goumnerova, L., Proctor, M. R., Madsen, J. R., Scott, R. 2009; 4 (3): 275-279

  Abstract

  Patients who have undergone myelomeningocele or lipomyelomeningocele repair may present with symptomatic retethering of the spinal cord. The authors describe the results as well as the utility of urological testing in pediatric patients undergoing multiple repeat untethering operations.The authors reviewed the records of 13 patients with lipomyelomeningocele or myelomeningocele who underwent at least 2 untethering procedures after their initial repair and who had urodynamic testing within 6 months prior to and 6 months following each untethering operation. In each case, urological testing included a slow-fill cystometrogram and an external urethral sphincter electromyogram using a concentric needle electrode to analyze individual motor unit action potentials at rest, in response to sacral reflexes, and during bladder filling and emptying.New urinary symptoms were identified in 7 of 13 cases prior to surgery. Postoperative subjective improvement in urinary symptoms was noted in 5 of these 7 cases. Improvement in bladder function on urodynamic testing correlated with symptomatic improvement. Sphincter electromyography findings did not correlate with changes in preoperative symptoms or postoperative improvement.In patients undergoing multiple repeat spinal cord untethering operations, measuring bladder function is more useful than sphincter electromyographty when selecting candidates for surgery and for measuring surgical outcomes.

  View details for DOI 10.3171/2009.4.PEDS0952

  View details for Web of Science ID 000269223300014

  View details for PubMedID 19772414

• Prevalence of pineal cysts in children and young adults JOURNAL OF NEUROSURGERY-PEDIATRICS Al-Holou, W. N., Garton, H. L., Muraszko, K. M., Ibrahim, M., Maher, C. O. 2009; 4 (3): 230-236

  Abstract

  Pineal cysts are a frequent incidental finding on intracranial imaging. In adults, the prevalence of pineal cysts is estimated to be 1.1-4.3%. However, the prevalence is not well established in younger patients.The authors retrospectively reviewed a consecutive series of 14,516 patients 25 years of age and younger, who underwent brain MR imaging at a single institution over an 11-year period. In patients identified with pineal cysts, the authors analyzed the images according to cyst size, signal characteristics, enhancement pattern, and evidence of local mass effect. Patient characteristics including demographics and other intracranial diagnoses were collected in the pineal cyst population and compared with a randomly selected age- and sex-matched control patient population. The data were evaluated using univariate and multivariate logistic regression, linear regression, and ANOVA.The authors identified 288 pineal region cysts (2.0%). The prevalence of pineal cysts was higher in female (2.4%) than in male patients (1.5%; p < 0.001). Pineal cysts were identified in patients of all ages, with an increased prevalence found in older patients (p < 0.001). Pineal cyst size was similar for all age and sex groups.Pineal cysts are common in the pediatric population, with an increased prevalence in girls and in older patients.

  View details for DOI 10.3171/2009.4.PEDS0951

  View details for Web of Science ID 000269223300006

  View details for PubMedID 19772406

• The outcome of tethered cord release in secondary and multiple repeat tethered cord syndrome Clinical article Al-Holou, W. N., Muraszko, K. M., Garton, H. J., Buchman, S. R., Maher, C. O. AMER ASSOC NEUROLOGICAL SURGEONS. 2009: 28-36

  Abstract

  After primary repair of a myelomeningocele or a lipomyelomeningocele, patients can present with symptoms of secondary tethered cord syndrome (TCS). After surgical untethering, a small percentage of these patients can present with multiple repeat TCS. In patients presenting with secondary or multiple repeat TCS, the role as well the expected outcomes of surgical untethering are not well defined.Eighty-four patients who underwent spinal cord untethering after at least 1 primary repair were retrospectively evaluated using scaled and subjective outcome measures at short-term and long-term follow-up visits. Outcomes were analyzed for predictive measures using multivariate logistic regression.Surgical untethering was performed in 66 patients with myelomeningoceles and 18 patients with lipomyelomeningoceles. Fourteen patients underwent multiple repeat spinal cord untethering. Patients were followed up for an average of 6.2 years. Most patients had stability of function postoperatively. Motor function and weakness improved in 7 and 16% of patients at 6 months, respectively, and 6 and 19% of patients at long-term follow-up evaluation, respectively. Of the patients who presented with back pain, 75% had improvement in symptoms at 6 months postoperatively. Younger age at untethering was significantly associated with worse long-term neurological outcomes. The number of previous untethering procedures, original diagnosis, sex, anatomical level, and degree of untethering had no effect on surgical outcomes.Patients presenting with secondary or multiple repeat TCS may benefit from surgical untethering.

  View details for DOI 10.3171/2009.2.PEDS08339

  View details for Web of Science ID 000267384000011

  View details for PubMedID 19569907

• Tethered cord release Response JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O., Garton, H. J., Muraszko, K. M. 2009; 4 (1): 27

  View details for Web of Science ID 000267384000010

• Linear vein-based arteriovenous malformations in children Clinical article JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O., Scott, R. 2009; 4 (1): 12-16

  Abstract

  The authors reviewed the experience of a single surgeon in the surgical treatment of arteriovenous malformations (AVMs) in children, with specific attention to the angioarchitectural appearance of these lesions. Methods The authors performed a retrospective review of pediatric cases of AVM treated at a single institution over a 15-year period. Inclusion criteria consisted of pediatric age at time of treatment and resection of a pial AVM. The AVMs were considered linear-based if they had a single, centrally located, dominant vein with a linear configuration rather than the typical central nidus.Sixty-seven patients, ranging in age from 6 months to 17 years, underwent surgical treatment of an AVM between January 1, 1990, and December 30, 2005. In these patients, 31 AVMs (46%) had a distinct linear configuration that was centered on a dominant draining vein ("vein-based"). These AVMs presented with hemorrhage (61%), incidental findings on imaging (16%), or seizures (13%). In 4 cases, AVM recurrence was noted on angiographic follow-up after postoperative angiography showed no residual lesion. Recurrence was seen at 1 year in 2 cases, and at 3 and 11 years in 1 case each.A linear vein-based morphological pattern is common in pediatric AVMs and may recapitulate the embryological origins of the cerebral circulation. Surgical treatment in these cases can also be vein-based, through a narrow surgical corridor, which leads to minimal cortical disruption.

  View details for DOI 10.3171/2009.1.PEDS08329

  View details for Web of Science ID 000267384000006

  View details for PubMedID 19569903

• Linear vein-based arteriovenous malformations Response JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O., Scott, R. 2009; 4 (1): 11

  View details for Web of Science ID 000267384000005

• Nonaccidental head injury in children Historical vignette JOURNAL OF NEUROSURGERY-PEDIATRICS Al-Holou, W. N., O'Hara, E. A., Cohen-Gadol, A. A., Maher, C. O. 2009; 3 (6): 474-483

  Abstract

  Our current understanding of nonaccidental head injury in children is the result of decades of effort and the tireless work of numerous physicians. In 1860 Auguste Ambroise Tardieu, a French forensics expert, recognized important patterns of injury in children and identified nonaccidental trauma as the cause of these injuries. His work was ignored. In the years that followed, physicians continued to report these patterns of injury but were unable to identify the etiology. A fundamental misunderstanding of the usual cause of subdural hematoma (SDH) contributed to the confusion at that time. Early in the 20th century, neurosurgeons such as Wilfred Trotter recognized that SDHs were traumatic in origin. However, even Trotter's efforts to expose faults in the theories that SDHs primarily resulted from inflammatory or infectious processes were not accepted immediately. Eventually, the pattern of injuries in children was again recognized both by neurosurgeons, who began to identify an association between trauma-induced SDHs and retinal hemorrhages, and by radiologists, who began to note SDHs in conjunction with osseous lesions. Not until the 1950s and 1960s, however, did physicians begin to routinely identify nonaccidental trauma as the cause of these injuries. Following the recognition of child abuse, a pattern of injuries in conjunction with shaking was identified and is currently known as shaken baby syndrome. Since its identification, our understanding of this syndrome has been modified as a result of new medical research, legal challenges, and popular media forces.

  View details for DOI 10.3171/2009.1.PEDS08365

  View details for Web of Science ID 000266461100008

  View details for PubMedID 19485731

• Calling things what they are Response JOURNAL OF NEUROSURGERY-PEDIATRICS Maher, C. O. 2009; 3 (6): 473

  View details for Web of Science ID 000266461100007

• Secondary tethered cord syndrome in patients with myelomeningocele JOURNAL OF PEDIATRIC REHABILITATION MEDICINE Al-Holou, W. N., Garton, H. L., Muraszko, K. M., Maher, C. O. 2009; 2 (1): 29-36

  Abstract

  Myelomeningocele is associated with other neurological abnormalities, including hydrocephalus, Chiari II malformations, syringomyelia, and secondary tethered cord syndrome. Tethered cord syndrome occurs because of abnormal attachment of the spinal cord to the caudal dural sac, causing cord ischemia. Occasionally, symptoms of progressive neurological deterioration may occur and can significantly affect the long-term outcome of these patients. Proper management of patients with myelomeningocele requires long-term follow-up and evaluation of signs of neurological deterioration that suggest secondary tethered cord syndrome. Treatment of these patients may target symptoms, such as urological intervention for bladder dysfunction, or it may target the tethered cord itself. Recently, many studies have shown that tethered cord release can significantly improve symptoms in these patients.

  View details for DOI 10.3233/PRM-2009-0060

  View details for Web of Science ID 000448264800004

  View details for PubMedID 21791792

• Pediatric Neurosurgery Current Diagnosis and Treatment: Surgery Song , D., Maher , C., Muraszko , K. Doherty G McGraw Hill. 2009: 850-864
• Transvenous embolization of a high-flow, posttraumatic fistula between the posterior communicating artery and retroclival venous plexus JOURNAL OF NEUROSURGERY Gandhi, D., Ansari, S. A., Thompson, B., Maher, C. 2009; 110 (1): 106-108

  Abstract

  Traumatic injuries of the posterior communicating artery are distinctly rare. We report an unusual case of traumatic tear of the posterior communicating artery with fistulous communication to the adjacent, retroclival venous plexus. The fistula, and an accompanying large venous aneurysm, was completely occluded via transvenous embolization. The patency of the posterior communicating artery was preserved.

  View details for DOI 10.3171/2008.5.17577

  View details for Web of Science ID 000262016200019

  View details for PubMedID 18847345

• Recurrence of dysembryoplastic neuroepithelial tumor following resection PEDIATRIC NEUROSURGERY Maher, C. O., White, J., Scheithauer, B. W., Raffel, C. 2008; 44 (4): 333-336

  Abstract

  Dysembryoplastic neuroepithelial tumor (DNT) is an increasingly recognized surgically curable tumor that characteristically presents with seizures in children. We report a case of a patient who underwent resection of a histologically proven DNT at 6 years of age. The resection was thought to be total at the time of surgery, and this impression was confirmed on postoperative imaging. Following the initial resection, the patient underwent surveillance imaging at regular intervals. Six years following the initial surgery, surveillance imaging demonstrated an enlarging area of signal abnormality at the site of the prior resection. The patient underwent a second resection with pathological confirmation of DNT recurrence. Although recurrence of DNT following resection is rare, this case suggests that surveillance imaging may have a role in patients with DNT, even following resections that are thought to be complete.

  View details for DOI 10.1159/000138372

  View details for Web of Science ID 000258318800013

  View details for PubMedID 18552517

• Ophthalmic Segment Aneurysms Neurosurgical Operative Atlas 2E: Vascular Neurosurgery Day , A., Du , R., Maher , C. Macdonald RL Thieme. 2008: 7-13
• Vascular Malformations of the spinal cord Surgery of the Pediatric Spine Maher , C., Smith , E., Proctor , M., Scott , R. Kim DH, Betz RR, Huhn SL, Newton PO Thieme. 2008: 337-343
• Spinal disorders associated with skeletal dysplasias and syndromes NEUROSURGERY CLINICS OF NORTH AMERICA Song, D., Maher, C. O. 2007; 18 (3): 499-+

  Abstract

  Skeletal dysplasias are a heterogeneous group of disorders in which there is abnormal cartilage and bone formation, growth, and remodeling. There are more than 200 described skeletal dysplasias. Skeletal dysplasias can affect the spine in various ways, with attendant neurosurgical implications for diagnosis and treatment. Craniocervical junction abnormalities, atlantoaxial subluxation, and kyphoscoliotic deformity are among the common spinal problems that are found in certain skeletal dysplasias.

  View details for DOI 10.1016/j.nec.2007.05.004

  View details for Web of Science ID 000249069900006

  View details for PubMedID 17678751

• Outcome following multiple repeated spinal cord untethering operations JOURNAL OF NEUROSURGERY Maher, C. O., Goumnerova, L., Madsen, J. R., Proctor, M., Scott, R. 2007; 106 (6): 434-438

  Abstract

  Patients who have undergone prior myelomeningocele or lipomyelomeningocele repair may present with symptomatic retethering of the spinal cord. In some cases, symptomatic tethering may recur after previous untethering operations. The expected outcome following repeated untethering in a patient after two or more prior untethering operations is not well described.The authors examined surgical indications, techniques, and outcomes for 30 repeated untethering operations in 22 patients who had undergone a previous repair of the primary spinal disorder and at least two subsequent untethering operations. The mean age at repeated untethering was 12.3 years. Presenting symptoms were pain (70%), weakness (70%), urinary symptoms (57%), and sensory changes (27%). The mean duration of symptoms was 7.5 months, and a longer symptomatic interval correlated with an increased number of prior operations. Total circumferential untethering was accomplished in 11 cases (37%). Postoperative symptomatic improvement was noted most often for pain (81%), and less often for urinary symptoms (53%) and weakness (48%). Complications included postoperative cerebrospinal fluid leakage or pseudomeningocele and new postoperative lower-extremity dysesthesia in five cases (17%). An increasing number of prior untethering operations was associated with a worse result for pain relief and a greater chance of significant morbidity.Multiple repeated untethering operations offer symptomatic relief to well-selected patients with this condition.

  View details for DOI 10.3171/ped.2007.106.6.434

  View details for Web of Science ID 000246973000003

  View details for PubMedID 17566398

• Very low pressure hydrocephalus - Report of two cases JOURNAL OF NEUROSURGERY Clarke, M. J., Maher, C. O., Nothdurft, G., Meyer, F. 2006; 105 (3): 475-478

  Abstract

  Low-pressure hydrocephalus is an extremely rare condition. Authors of the few previous reports on this subject have suggested that symptoms are gradual in onset and successfully treated. In this report the authors presented two unique cases of very low pressure hydrocephalus in which the patients experienced rapid deterioration requiring negative-pressure cerebrospinal fluid drainage to achieve the best possible neurological function; outcomes in both patients ultimately were poor. The constellation of findings suggests that this may be a distinct clinical entity.

  View details for DOI 10.3171/jns.2006.105.3.475

  View details for Web of Science ID 000239934200025

  View details for PubMedID 16961147

• Lumbar intramedullary spinal schistosomiasis presenting as progressive paraparesis: case report. Neurosurgery Kim, A. H., Maher, C. O., Smith, E. R. 2006; 58 (5): E996

  Abstract

  OBJECTIVE AND IMPORTANCE: Blood fluke infection or schistosomiasis affects up to 300 million people worldwide. Although infection of the hepatic and urogenital systems commonly occurs, central nervous system involvement is rare. When presenting in the spinal cord, schistosomiasis can be difficult to diagnose because it can present as mass lesion or transverse myelitis. We describe a patient with lumbar intramedullary spinal schistosomiasis who presented to a tertiary medical center in the United States and discuss the diagnosis and treatment of this rare disease.CLINICAL PRESENTATION: A 25-year-old Brazilian man presented with progressive, subacute, bilateral lower extremity motor and sensory deficits and disturbances in bladder function. Magnetic resonance imaging revealed a diffusely enhancing mass expanding the region of the conus medullaris.INTERVENTION: Laboratory investigation disclosed serum and cerebrospinal fluid eosinophilia. Ultimately, cerebrospinal fluid serology demonstrated the presence of Schistosoma mansoni. The patient was treated with praziquantel and steroids and made a marked recovery.CONCLUSION: The clinical and radiographic manifestations of spinal schistosomiasis can mimic those of intra-axial spinal tumors and transverse myelitis. To avoid unnecessary surgery or delay in treatment, the clinician must have knowledge of this type of presentation. The increasing volume of international travel and high prevalence of the disease worldwide increases the possibility that the practicing neurosurgeon in the United States may encounter this rare but treatable disease.

  View details for DOI 10.1227/01.NEU.0000210223.25400.C7

  View details for PubMedID 16639309

• Pediatric neurosurgery. Progress in neurological surgery Maher, C. O., Cohen-Gadol, A. A., Raffel, C. 2006; 19: 97-106

  Abstract

  Randomized controlled trials of neurosurgical procedures involving children have been organized infrequently; as a consequence, the majority of pediatric neurosurgical practice is not supported by class I data. Furthermore, many trials that have been reported suffer from serious methodological shortcomings such as insufficient power and poor statistical analysis. Finally, several trials of neurosurgical techniques that are frequently performed on children have either excluded children from participation or include an insufficient number of children to draw strong conclusions. Despite these shortcomings, pediatric neurosurgery, like all fields in medicine, is gradually moving towards a more stringent evidence-based medicine standard. This chapter will attempt to summarize the recent progress that has been made in this area.

  View details for DOI 10.1159/000095185

  View details for PubMedID 17033149

• Pediatric Neurosurgery Guiding Neurosurgery by Evidence Maher , C., Cohen-Gadol , A., Raffel , C. Pollock BE, ed Karger, Basel. 2006: pp97-106
• Central Nervous System Tumors Oncology: An evidence based approach Rao , R., Brown , P., Giannini , C., Maher , C., Meyer , F., Galanis , E., Erickson , B., Buckner , J. Chang AE, Ganz PA, Hayes DF, Kinsella TJ, Pass HI, Schiller JH, Stone RM, Strecher VJ Springer Verlag. 2006: 487-505
• Cushing's experience with the surgical treatment of spinal dysraphism JOURNAL OF NEUROSURGERY Cohen-Gadol, A. A., Nahed, B. V., Voorhees, Maher, C. O., Spencer, D. D. 2005; 102 (4): 441-444

  Abstract

  Although Harvey Cushing is best known for his role in developing surgical treatments for tumors of the central nervous system, he performed diverse neurosurgical procedures throughout his career, both at The Johns Hopkins Hospital (1886--1912) and at the Peter Bent Brigham Hospital (1912--1932). His unique and innovative approach to the treatment of myelomeningoceles associated with hydrocephalus, displayed early in his career, is characteristic of his attempts to circumvent the technical limitations of his time in the management of neurosurgical problems. In this report, the authors discuss the evolution of Cushing's technique in the treatment of myelomeningoceles through two illustrative patient records.

  View details for DOI 10.3171/ped.2005.102.4.0441

  View details for Web of Science ID 000229249600020

  View details for PubMedID 15926402

• Transorbital penetrating brainstem injury in a child - Case report JOURNAL OF NEUROSURGERY Jacob, J. T., Cohen-Gadol, A. A., Maher, C. O., Meyer, F. B. 2005; 102 (3): 350-352

  Abstract

  The authors present the unusual case of a 9-year-old girl who sustained injury to her brainstem as a result of the orbital penetration of a metal projectile (nail) into the juxtamedullary region. This case and others reported in the literature associate this type of injury with relatively minor complications. Thorough imaging of the intracranial contents and surgical removal of the projectile is recommended.

  View details for DOI 10.3171/ped.2005.102.3.0350

  View details for Web of Science ID 000228646600020

  View details for PubMedID 15881766

• Primitive Neuroectodermal Tumors Cancer and the Nervous System Raffel , C., Maher , C. Schiff D, O'Neill BP McGraw-Hill. 2005: 415-430
• Surgical treatment of pediatric cerebral aneurysms Pediatric Neurovascular Disease: Surgical and Endovascular Management Maher , C., Meyer , F. Alexander MJ, Spetzler RF Thieme. 2005: 83-89
• Neurosurgical treatment of brain tumors in children PEDIATRIC CLINICS OF NORTH AMERICA Maher, C. O., Raffel, C. 2004; 51 (2): 327-+

  Abstract

  Primary brain tumors are the most common solid neoplasms of childhood. The diagnosis of brain tumors in the general pediatric population remains challenging. Nevertheless, it is clear that refinements in imaging, surgical technique, and adjunctive therapies have led to longer survival and an improving quality of life in children with brain tumors.

  View details for DOI 10.1016/S0031-3955(03)00206-2

  View details for Web of Science ID 000221096000005

  View details for PubMedID 15062674

• The Unstable Spine after Trauma Tough Calls in Acute Neurology Cohen-Gadol, A., Maher , C., Krauss , W. Rabinstein AA, Wijdicks EFM Elsevier. 2004: 309- 318
• Medulloblastoma Textbook of Neuro-Oncology Maher , C., Raffel , C. Berger MS ans Brem H Elsevier. 2004
• Evaluation of a novel propylene oxide-treated collagen material as a dural substitute JOURNAL OF NEUROSURGERY Maher, C. O., Anderson, R. E., McClelland, R. L., Link, M. J. 2003; 99 (6): 1070-1076

  Abstract

  The authors evaluated a new non-cross-linked, propylene oxide-treated, acellular collagen matrix for use as a dural substitute in rabbits. They then compared this material to a commonly used dural substitute as well as to native dura mater used during primary closure.Forty-six rabbits were randomly assigned to eight groups of five or six rabbits each. These groups differed according to the type of closure material that was used during surgery (native dura, control dural substitute, or experimental dural substitute) and the duration of convalescence. At the end of the experiment, the tightness of the duraplasty was assessed in each live rabbit by continuous infusion of fluid into the cistema magna until leakage was detected. The animals were killed and each specimen was sectioned and studied histologically. The authors found that the experimental dural substitute was safe in animals for this application, that it held sutures well, and that a watertight closure was usually achieved. There were fewer adhesions between the experimental material and neural tissue was less likely to adhere to the cranium than the control graft. Histological examination showed that the experimental material had slightly more spindle cells and vascularity than the control graft.The experimental graft material has several features that make it an attractive candidate for use as a dural substitute.

  View details for Web of Science ID 000187111700019

  View details for PubMedID 14705736

• Interleukin-1β and adverse effects on cerebral blood flow during long-term global hypoperfusion JOURNAL OF NEUROSURGERY Maher, C. O., Anderson, R. E., Martin, H. S., McClelland, R. L., Meyer, F. B. 2003; 99 (5): 907-912

  Abstract

  The effects of interleukin (IL)-1beta on the cerebral vasculature are complex and incompletely understood. Many pathophysiological states in which inflammatory cascades have been implicated also have varying degrees of cerebral hypoperfusion. The purpose of this investigation was to examine the long-term effects of this proinflammatory cytokine and its antagonist on cerebral blood flow (CBF) following global cerebral hypoperfusion.Sprague-Dawley rats were randomly assigned to 12 groups and given continuous intracerebroventricular (ICV) infusions of IL-1beta, the IL-1 receptor antagonist (IL-1ra), or saline vehicle (control). Global cerebral hypoperfusion was produced by occlusion of both carotid arteries and one vertebral artery. Cerebral blood flow was measured at baseline and again after initiation of the infusions by performing a 133Xe clearance study. Prolonged ICV administration of IL-1beta resulted in a significant decrease in CBF compared with that in controls. Prolonged administration of the antagonist IL-1ra resulted in significant increases in CBF compared with that in both IL-1beta-treated animals and controls.This experiment demonstrates that long-term treatment with the proinflammatory cytokine IL-1beta adversely affects CBF.

  View details for DOI 10.3171/jns.2003.99.5.0907

  View details for Web of Science ID 000186237400019

  View details for PubMedID 14609172

• Cortical resection for epilepsy in children with linear sebaceous nevus syndrome PEDIATRIC NEUROSURGERY Maher, C. O., Cohen-Gadol, A. A., Raffel, C. 2003; 39 (3): 129-135

  Abstract

  Linear sebaceous nevus syndrome (LSNS) is a rare neurocutaneous syndrome that is associated with seizures and mental retardation. The cortical abnormalities that are associated with this syndrome include focal cortical dysplasia, partial hemimegalencephaly and holohemispheric hemimegalencephaly. Few reports have addressed the utility of cortical resections for epilepsy treatment in the setting of LSNS. We report 3 children with this syndrome who underwent extensive cortical resections and experienced significant improvement in seizure frequency. Our results support the utility of extensive cortical resections for children with this condition.

  View details for DOI 10.1159/000071649

  View details for Web of Science ID 000184775000003

  View details for PubMedID 12876391

• Arteriovenous malformation in the trigeminal nerve - Case report JOURNAL OF NEUROSURGERY Maher, C. O., Atkinson, J. L., Lane, J. I. 2003; 98 (4): 908-912

  Abstract

  The authors report on an arteriovenous malformation (AVM) within the trigeminal nerve in an otherwise healthy 76-year-old man who presented with the sudden onset of headache and ataxia. The AVM was totally resected via a lateral suboccipital approach to the cerebellopontine angle. Dural arteriovenous fistulas and AVMs of the dorsal root entry zone and adjacent brainstem that compress the trigeminal nerve have been previously described. To the authors' knowledge, this is the first reported case of an angiographically, surgically, and pathologically proven AVM arising from within the trigeminal nerve itself.

  View details for DOI 10.3171/jns.2003.98.4.0908

  View details for Web of Science ID 000181922400028

  View details for PubMedID 12691421

• Surgical treatment of fibrous dysplasia of the skull in children PEDIATRIC NEUROSURGERY Maher, C. O., Friedman, J. A., Meyer, F. B., Lynch, J. J., Unni, K., Raffel, C. 2002; 37 (2): 87-92

  Abstract

  We evaluate the role of surgery in the treatment of fibrous dysplasia of the skull in children.We identified 48 consecutive cases of fibrous dysplasia of the skull that were surgically treated at a single institution over a 23-year interval. The 28 patients that initially presented during the first two decades of life were selected for further analysis. Presenting symptoms, signs, surgical treatment, surgical outcome and the state of the disease at the extended follow-up interval were recorded.Fibrous dysplasia of the skull in children most often involved the frontal, sphenoid and ethmoid bones. Most patients presented with facial asymmetry or proptosis. A gross total resection was achieved in 7 patients, subtotal resection in 17 patients, and 4 patients underwent biopsy alone. Over the follow-up interval, 7 patients had symptomatic progression of subtotally resected fibrous dysplasia and 3 patients had asymptomatic progression. The extent of resection was correlated with recurrence risk.In order to prevent progression of disease, an attempt at gross total resection is indicated in cases of fibrous dysplasia of the skull in childhood where the risk of neurologic morbidity is low and cosmetic results will be acceptable.

  View details for DOI 10.1159/000065110

  View details for Web of Science ID 000177305000005

  View details for PubMedID 12145517

• Intraoperative lidocaine injection into the carotid sinus during endarterectomy JOURNAL OF NEUROSURGERY Maher, C. O., Wetjen, N. M., Friedman, J. A., Meyer, F. B. 2002; 97 (1): 80-83

  Abstract

  Many surgeons inject a local anesthetic agent into the carotid sinus before carotid endarterectomy in an attempt to ameliorate perioperative hemodynamic instability. The purpose of this study is to analyze the effect of carotid sinus injection with lidocaine on perioperative hemodynamics and complications.The authors prospectively studied 92 patients in whom 100 consecutive carotid endarterectomies were performed by a single surgeon (eight procedures were bilateral). Patients were randomly assigned to one of two groups, in which either 0.5 ml of 1% lidocaine was injected into the carotid sinus nerve or no injection of lidocaine was administered before the arteriotomy. All patients were treated postoperatively according to a standard endarterectomy protocol. There were no significant differences between the two groups in the incidence of hypertension, hypotension, or the use of vasoactive medications in the operating room following restoration of carotid artery (CA) blood flow, in the recovery room, or in the intensive care unit.Injection of lidocaine into the carotid sinus at the time of endarterectomy is not associated with a significant improvement in any hemodynamic factor, from the time of restoration of CA blood flow to postoperative Day 1.

  View details for DOI 10.3171/jns.2002.97.1.0080

  View details for Web of Science ID 000176665000012

  View details for PubMedID 12134936

• Frontal lobe epilepsy: diagnosis and surgical treatment NEUROSURGICAL REVIEW Wetjen, N. M., Cohen-Gadol, A. A., Maher, C. O., Marsh, W. R., Meyer, F. B., Cascino, G. D. 2002; 25 (3): 119-138

  Abstract

  Frontal lobe epilepsy has been better understood during the past two decades with the advent of technologies with improved localizing capabilities. Major technological advances in the ability to delineate structural and functional brain regions have led to a resurgence of interest in epilepsy surgery. Neuroimaging modalities have broadened the scope of what are now considered surgically remediable syndromes. In the following article, we attempt to review the current concepts regarding diagnosis and surgical management of frontal lobe epilepsy.

  View details for DOI 10.1007/s101430100174

  View details for Web of Science ID 000176735200001

  View details for PubMedID 12135227

• Use of cerebrospinal fluid flow rates measured by phase-contrast MR to predict outcome of ventriculoperitoneal shunting for idiopathic normal-pressure hydrocephalus MAYO CLINIC PROCEEDINGS Dixon, G. R., Friedman, J. A., Luetmer, P. H., Quast, L. M., McClelland, R. L., Petersen, R. C., Maher, C. O., Ebersold, M. J. 2002; 77 (6): 509-514

  Abstract

  To determine whether favorable clinical response and magnitude of improvement are associated with increased aqueductal cerebrospinal fluid (CSF) flow rates in patients who undergo ventriculoperitoneal shunting (VPS) for idiopathic normal-pressure hydrocephalus (NPH).Between January 1995 and June 2000, 49 patients (14 men and 35 women; mean age, 72.9 years; range, 54-88 years) underwent magnetic resonance quantification of aqueductal CSF flow followed by VPS for presumed idiopathic NPH at the Mayo Clinic, Rochester, Minn. Logistic regression models for the odds of any improvement in score as a function of aqueductal CSF flow and separate models for any improvement in gait, incontinence, cognition, and total score were constructed.Forty-two patients (86%) had improvement in gait at postoperative follow-up (mean, 10 months). Of the 32 patients with incontinence, 27 (69%) improved. Of the 36 patients with cognitive impairment, 16 (44%) improved. In univariate and fully adjusted models, increased CSF flow through the aqueduct was not significantly associated with improvement or the magnitude of improvement in gait, cognition, or incontinence. Thirty-six patients underwent high-volume lumbar puncture preoperatively, of whom 5 (14%) had no response. The aqueductal CSF flow rates of these 5 patients were significantly higher than those of the patients who improved after lumbar puncture. Postoperative complications occurred in 15 patients. The aqueductal CSF flow rates in these 15 patients were not significantly different from those of patients who experienced no complications.Among patients who underwent VPS for the treatment of NPH, measurement of CSF flow through the cerebral aqueduct did not reliably predict which patients would improve after shunting or the magnitude of improvement.

  View details for DOI 10.4065/77.6.509

  View details for Web of Science ID 000176018900003

  View details for PubMedID 12059119

• Neuromuscular choristoma of the sciatic nerve - Case report JOURNAL OF NEUROSURGERY Maher, C. O., Spinner, R. J., Giannini, C., Scheithauer, B. W., Crum, B. A. 2002; 96 (6): 1123-1126

  Abstract

  The authors report the findings of a neuromuscular choristoma of the sciatic nerve in an otherwise healthy 18-year-old man who presented with sensorimotor symptoms and deformities of the right leg and foot. Only a few cases of this rare tumor, also known as "neuromuscular hamartoma" or "benign triton tumor," have been reported in the surgical literature. The authors discuss the clinical presentation, radiological findings, pathological diagnosis, and surgical rationale for this case and review the associated literature.

  View details for DOI 10.3171/jns.2002.96.6.1123

  View details for Web of Science ID 000176026900029

  View details for PubMedID 12066915

• Spontaneous CSF leaks: Underlying disorder of connective tissue NEUROLOGY Mokri, B., Maher, C. O., Sencakova, D. 2002; 58 (5): 814-816

  Abstract

  Of 58 consecutive patients with spontaneous CSF leaks, nine exhibited features of connective tissue disorder. One had Marfan's syndrome. Five additional patients had hyperflexible joints, of whom four had arachnodactyly, four were tall and slender, two had hyperextensible skin, and one had a strong family history of abdominal aorta aneurysms. Retinal detachment at a young age was noted in two. One patient had bilateral carotid dissections. A dural weakness may predispose patients to spontaneous CSF leak.

  View details for DOI 10.1212/WNL.58.5.814

  View details for Web of Science ID 000174301300024

  View details for PubMedID 11889250

• Spontaneous disc space infections in adults SURGICAL NEUROLOGY Friedman, J. A., Maher, C. O., Quast, L. M., McClelland, R. L., Ebersold, M. J. 2002; 57 (2): 81-86

  Abstract

  Spontaneous discitis typically affects children; much less is known about the disease in adults. We examined the clinical characteristics and the role of surgery in spontaneous infectious discitis in adults.Twenty-nine consecutive adult patients (16 men, 13 women) with spontaneous infectious discitis were treated by a single surgeon (MJE) over a 5-year period. These patients were compared to 19 consecutive patients with postoperative discitis over the same time period. Mean follow-up was 2.4 years.The average age of patients with spontaneous discitis was 69.0 years. Eleven of these patients (38%) were diabetic and 9 (31%) had a known concurrent infection. Infections occurred at cervical (10%), thoracic (34%), and lumbar interspaces (59%), and at multiple disc spaces in eight cases (28%). Ten patients (34%) had an elevated serum leukocyte count and 21 patients (72%) had an elevated erythrocyte sedimentation rate. While Gram-positive infection was most common, a broad spectrum of microbes was isolated. All patients were treated with i.v. antibiotics for a mean duration of 6 weeks. Four patients required surgical fusion; the rest were treated with external immobilization. At follow-up, 21 patients (72%) were symptom-free, 3 patients (10%) had ongoing disease, and 5 patients (17%) had died of unrelated causes. Compared to patients with postoperative discitis treated over the same time period, spontaneous discitis in adults affected older patients and required a broader spectrum of antibiotic coverage. Outcomes were similar between the two groups.While spontaneous discitis has predominantly been reported in children, the disease also affects older adults. Spontaneous discitis in adults is associated with advanced age, diabetes mellitus, and systemic infection. Elevated serum leukocyte count lacks diagnostic sensitivity. A high cure rate is achieved with antibiotics and external immobilization. Surgical treatment is rarely required.

  View details for DOI 10.1016/S0090-3019(01)00681-4

  View details for Web of Science ID 000174578900001

  View details for PubMedID 11904193

• Surgical procedures for nonatherosclerotic disorders of the extracranial carotid artery Textbook of Neurological Surgery: Principles and Practice Maher , C. Batjer HH and Loftus CM Lippincott Williams and Wilkins. 2002: 2270- 2279
• Posterior fossa tumors in children Textbook of Neurological Surgery: Principles and Practice Maher , C., Friedman , J., Raffel , C. Batjer HH and Loftus CM Lippincott Williams and Wilkins. 2002: 985-998
• Compelling reasons to screen brain in HHT - Response STROKE Maher, C. O., Piepgras, D. G., Brown, R. D., Friedman, J. A., Pollock, B. E. 2001; 32 (12): 2958

  View details for Web of Science ID 000172599500052

• Remote cerebellar hemorrhage after supratentorial surgery NEUROSURGERY Friedman, J. A., Piepgras, D. G., Duke, D. A., McClelland, R. L., Bechtle, P. S., Maher, C. O., Morita, A., Perkins, W. J., Parisi, J. E., Brown, R. D. 2001; 49 (6): 1327-1340

  Abstract

  Remote cerebellar hemorrhage (RCH) is an infrequent and poorly understood complication of supratentorial neurosurgical procedures. We retrospectively compared 42 patients who experienced RCH with a case-matched control cohort, to delineate risk factors associated with the occurrence of this complication.Between 1988 and 2000, 42 patients experienced RCH after supratentorial neurosurgical procedures at our institution. Diagnoses were made on the basis of postoperative computed tomographic or magnetic resonance imaging findings in all cases. The medical records for these patients were reviewed and compared with those for a control cohort of 43 patients, matched for age, sex, surgical lesion, and type of craniotomy, who were treated during the same period.RCH most commonly occurred after frontotemporal craniotomies for unruptured aneurysm repair or temporal lobectomy and was frequently an incidental finding on postoperative computed tomographic scans. However, some cases of RCH were associated with significant morbidity, and two patients died. Preoperative aspirin use and elevated intraoperative systolic blood pressure were significantly associated with RCH (P = 0.026 and P = 0.036, respectively). Pathological findings for two cases demonstrated hemorrhagic infarctions in both.RCH most commonly follows supratentorial neurosurgical procedures, performed with the patient in the supine position, that involve opening of cerebrospinal fluid cisterns or the ventricular system (such as unruptured aneurysm repair or temporal lobectomy). Preoperative aspirin use and moderately elevated intraoperative systolic blood pressure are potentially modifiable risk factors associated with the development of RCH. Although RCH can cause death or major morbidity, most cases are asymptomatic or exhibit a benign course. Cerebellar "sag" as a result of cerebrospinal fluid hypovolemia, causing transient occlusion of superior bridging veins within the posterior fossa and consequent hemorrhagic venous infarction, is the most likely pathophysiological cause of RCH.

  View details for DOI 10.1097/00006123-200112000-00008

  View details for Web of Science ID 000172474500013

  View details for PubMedID 11846932

• Fatal progression of posttraumatic dural arteriovenous fistulas refractory to multimodal therapy - Case report JOURNAL OF NEUROSURGERY Friedman, J. A., Meyer, F. B., Nichols, D. A., Coffey, R. J., Hopkins, N., Maher, C. O., Meissner, I. D., Pollock, B. E. 2001; 94 (5): 831-835

  Abstract

  The authors report the case of a man who suffered from progressive, disseminated posttraumatic dural arteriovenous fistulas (DAVFs) resulting in death, despite aggressive endovascular, surgical, and radiosurgical treatment. This 31-year-old man was struck on the head while playing basketball. Two weeks later a soft, pulsatile mass developed at his vertex, and the man began to experience pulsatile tinnitus and progressive headaches. Magnetic resonance imaging and subsequent angiography revealed multiple AVFs in the scalp, calvaria, and dura, with drainage into the superior sagittal sinus. The patient was treated initially with transarterial embolization in five stages, followed by vertex craniotomy and surgical resection of the AVFs. However, multiple additional DAVFs developed over the bilateral convexities, the falx, and the tentorium. Subsequent treatment entailed 15 stages of transarterial embolization; seven stages of transvenous embolization, including complete occlusion of the sagittal sinus and partial occlusion of the straight sinus; three stages of stereotactic radiosurgery; and a second craniotomy with aggressive disconnection of the DAVFs. Unfortunately, the fistulas continued to progress, resulting in diffuse venous hypertension, multiple intracerebral hemorrhages in both hemispheres, and, ultimately, death nearly 5 years after the initial trauma. Endovascular, surgical, and radiosurgical treatments are successful in curing most patients with DAVFs. The failure of multimodal therapy and the fulminant progression and disseminated nature of this patient's disease are unique.

  View details for DOI 10.3171/jns.2001.94.5.0831

  View details for Web of Science ID 000168524600022

  View details for PubMedID 11354419

• Ischemic complications of surgery for anterior choroidal artery aneurysms JOURNAL OF NEUROSURGERY Friedman, J. A., Pichelmann, M. A., Piepgras, D. G., Atkinson, J. L., Maher, C. O., Meyer, F. B., Hansen, K. K. 2001; 94 (4): 565-572

  Abstract

  Anterior choroidal artery (AChA) aneurysms account for 4% of all intracranial aneurysms. The surgical approach is similar to that for other supraclinoid carotid artery lesions, but surgery may involve a higher risk of debilitating ischemic complications because of the critical territory supplied by the AChA.Between 1968 and 1999, 51 AChA aneurysms in 50 patients were treated using craniotomy and clipping at the Mayo Clinic. There were 22 men (44%) and 28 women (56%) whose average age was 53 years (range 27-79 years). Twenty-four AChA aneurysms (47%) had hemorrhaged; nine patients (18%) had subarachnoid hemorrhage from another aneurysm. Three AChA aneurysms (6%) were associated with symptoms other than rupture. Forty-one patients (82%) achieved a Glasgow Outcome Scale (GOS) score of 4 or 5 at long-term follow up. The surgical mortality rate was 4%, and major surgical morbidity (GOS < or = 3) was 10%. Eight patients (16%) had clinically and computerized tomography-demonstrated AChA territory infarcts. Five of these strokes manifested in a delayed fashion 6 to 36 hours after the operation, and progressed from mild to complete deficit over hours. In 41 patients the aneurysm arose from the internal carotid artery adjacent to the AChA, and in nine patients the aneurysm arose directly from the origin of the AChA itself; four of these nine patients had postoperative infarction.Surgical treatment of AChA aneurysms involves a significant risk of debilitating ischemic complications. Most postoperative strokes occur in a delayed fashion, offering a potential therapeutic window. Patients with aneurysms arising from the AChA itself have an extremely high risk for postoperative stroke.

  View details for DOI 10.3171/jns.2001.94.4.0565

  View details for Web of Science ID 000167862300004

  View details for PubMedID 11302654

• Cerebrovascular manifestations in 321 cases of hereditary hemorrhagic telangiectasia STROKE Maher, C. O., Piepgras, D. G., Brown, R. D., Friedman, J. A., Pollock, B. E. 2001; 32 (4): 877-882

  Abstract

  Patients with hereditary hemorrhagic telangiectasia (HHT) are at risk for developing cerebral vascular malformations and pulmonary arteriovenous fistulae. We assessed the risk of neurological dysfunction from these malformations and fistulae.Three hundred twenty-one consecutive patients with HHT seen at a single institution over a 20-year period were studied. Any evidence of prior neurological symptoms or presence of an intracranial vascular malformation was recorded. All cases of possible cerebral arteriovenous malformation were confirmed by conventional arteriography.Twelve patients (3.7%) had a history of cerebral vascular malformations. Ten patients had arteriovenous malformations, 1 had a dural arteriovenous fistula, and 1 had a cavernous malformation. Seven patients (2.1%) presented with intracranial hemorrhage, 2 presented with seizures alone, and 3 were discovered incidentally. The average age at the time of symptomatic intracranial hemorrhage was 25.4 years. All patients with a history of intracranial hemorrhage were classified as Rankin grade I or II at a mean follow-up interval of 6.0 years. A history of cerebral infarction or transient ischemic attack was found in 29.6% of patients with HHT and a pulmonary arteriovenous fistula.The risk of intracranial hemorrhage is low among people with HHT. Furthermore, a majority of these patients have a good functional outcome after hemorrhage. The data do not suggest a compelling indication for routine screening of patients with HHT for asymptomatic cerebral vascular malformations. By comparison, pulmonary arteriovenous fistulae are a much more frequent cause of neurological symptoms in this population.

  View details for DOI 10.1161/01.STR.32.4.877

  View details for Web of Science ID 000167951300013

  View details for PubMedID 11283386

• Refractory idiopathic intracranial hypertension treated with stereotactically planned ventriculoperitoneal shunt placement. Neurosurgical focus Maher, C. O., Garrity, J. A., Meyer, F. B. 2001; 10 (2): E1

  Abstract

  Ventriculoperitoneal (VP) shunts have not been widely used for idiopathic intracranial hypertension (IIH) because of the difficulty of placing a shunt into normal or small-sized ventricles. The authors report their experience with stereotactic placement of VP shunts for IIH.The authors reviewed the clinical records of all patients in whom stereotaxis was used to guide the placement of a VP shunt for IIH at their institution. All shunts were placed using stereotactic guidance to target the frontal horn of the lateral ventricle. Patients were contacted at a mean postoperative interval of 15.1 months. No patients were lost to follow up. The authors identified 13 patients who underwent placement of a stereotactically guided VP shunt for IIH over a 6-year period. A trial of either acetazolamide or steroid therapy had failed in all patients. Prior surgical treatments included optic nerve sheath fenestrations in seven patients and cerebrospinal fluid diversionary procedures, other than stereotactic VP shunt procedures, in nine patients. Twelve patients reported excellent or good durable symptomatic relief at the time of follow up. No patient suffered progression of visual deficits. Four patients experienced persistent headaches following the procedure. Three patients required a revision of the VP shunt for technical failure.Stereotactically guided VP shunt placement is an effective and durable treatment option in many cases of IIH that are refractory to more traditional medical and surgical approaches.

  View details for DOI 10.3171/foc.2001.10.2.2

  View details for PubMedID 16749748

• Radiation induced vascular injury after stereotactic radiosurgery for trigeminal neuralgia: Case report SURGICAL NEUROLOGY Maher, C. O., Pollock, B. E. 2000; 54 (2): 189-193

  Abstract

  Stereotactic radiosurgery is increasingly used for the treatment of medically unresponsive trigeminal neuralgia.We present the case of a 69-year-old man with trigeminal neuralgia who underwent stereotactic radiosurgery after a failed balloon compression procedure. The radiosurgery also failed to provide the patient with any significant pain relief, and microvascular decompression of the trigeminal nerve was performed 10 months later. At operation, two adjacent veins and the superior cerebellar artery were noted to have focal changes consistent with atheromatous disease.We postulate that the recent radiation exposure resulted in the observed vascular injury. As a result, patients having trigeminal neuralgia radiosurgery need to be followed carefully for possible delayed ischemic events secondary to radiation-induced vascular injury.

  View details for DOI 10.1016/S0090-3019(00)00266-4

  View details for Web of Science ID 000165283500035

  View details for PubMedID 11077103

• Surgical treatment of spontaneous spinal cerebrospinal fluid leaks. Neurosurgical focus Maher, C. O., Meyer, F. B., Mokri, B. 2000; 9 (1): e7

  Abstract

  Spontaneous spinal cerebrospinal fluid (CSF) leaks are an increasingly recognized cause of intracranial hypotension. In this report the authors review the indications for surgery, surgical techniques, and surgery-related outcomes for these lesions. The major presenting symptoms include postural headaches, nausea, vomiting, and diplopia. Often, there is no history of traumatic injury. The most common cranial magnetic resonance (MR) imaging features include pachymeningeal gadolinium enhancement and sagging of the brain. On spinal MR images, diverticula are frequently noted. In cases in which symptoms are severe and refractory to less invasive measures, surgical intervention is indicated. Tears in the dura or leaking diverticula that are identified as the sources of the CSF leak often can be ligated or repaired. When a source of CSF egress is not found intraoperatively, packing the epidural space with blood-soaked Gelfoam or muscle at the appropriate level can lead to relief of symptoms. Occasionally the dural defect is large, irregular, or has attenuated borders that may not be possible to repair with sutures. These may be repaired by packing the defect with muscle or blood-soaked Gelfoam. Indications for and outcomes of surgery in patients with this condition will become more defined as surgeons gain experience with these procedures.

  View details for DOI 10.3171/foc.2000.9.1.7

  View details for PubMedID 16859268

• Early vasculopathy following radiation in a child with medulloblastoma PEDIATRIC NEUROSURGERY Maher, C. O., Raffel, C. 2000; 32 (5): 255-258

  Abstract

  A child with severe radiation vasculopathy 15 months following radiation therapy for medulloblastoma is reported. The patient underwent surgical resection of a posterior fossa medulloblastoma, followed by chemotherapy and radiation therapy. He was treated with 55 Gy to the craniospinal axis. Fifteen months later, the patient presented with a subacute neurologic deterioration from multiple ischemic events that resulted from severe radiation vascular injury. We compare and contrast this case to similar case reports in the literature.

  View details for DOI 10.1159/000028947

  View details for Web of Science ID 000089123200007

  View details for PubMedID 10965272

• Surgical treatment of nonatherosclerotic lesions of the extracranial carotid artery. Neurosurgery clinics of North America Maher, C. O., Meyer, F. B. 2000; 11 (2): 309-22

  Abstract

  Nonatherosclerotic disorders of the extracranial carotid artery, such as dissections, aneurysms, and carotid body tumors, are diverse in their causes, presentations, and modes of treatment. The surgical treatment of these lesions often will require a higher exposure of the extracranial carotid than is typical for a carotid endarterectomy. The prevention of perioperative ischemic injury assumes a major role in determining the surgical strategy for treating these lesions. This article offers a brief description of several of these disorders, a review of the general surgical approach to the high cervical artery, and a brief description of lesion-specific surgical techniques.

  View details for PubMedID 10733847

• Lateral exit-zone stenosis and lumbar radiculopathy JOURNAL OF NEUROSURGERY Maher, C. O., Henderson, F. C. 1999; 90 (1): 52-58

  Abstract

  Hypertrophy of the superior facet of the inferior vertebra, resulting in a compression of the nerve root at the lateral foraminal exit, is a recognized cause of radicular symptoms, particularly in patients in whom previous lumbar spine surgery has failed. The lesion-specific presenting symptoms, imaging findings, and surgical treatment of this lesion, however, have received little attention. The authors prospectively studied a series of eight consecutive patients, in whom a diagnosis of lumbar stenosis at the lateral foraminal exit had been made, to elucidate the common presenting signs and symptoms of this disorder, as well as to evaluate the success of the operative treatment.The eight patients were selected from a group of 250 consecutive patients who presented to a tertiary-care hospital and in whom a diagnosis of long-standing lumbar radiculopathy had been made. In all cases the diagnosis was confirmed by imaging studies and by intraoperative findings. The authors performed decompressive procedures on the nerve root via a medial facet-sparing approach.The authors conclude that this lesion presents with characteristic physical findings and on imaging studies that distinguish it from other causes of radiculopathy, and they propose a lesion-specific, facet-sparing surgical technique that has yielded excellent results.

  View details for DOI 10.3171/spi.1999.90.1.0052

  View details for Web of Science ID 000078774400009

  View details for PubMedID 10413126

• Results of a thyroid monitoring survey carried out on workers exposed to 125I in São Paulo, Brazil. Health physics Bartolini, P., Ribela, M. T., Araujo, E. A. 1988; 55 (3): 511-5

  Abstract

  The thyroids of 30 workers performing routine 125I labelling in several laboratories of the city of São Paulo have been monitored about once every 2-3 mo from November 1985 to October 1986. Twenty-five of them presented a significant radioactivity (in our detection system greater than 62 Bq), but none reached the maximum permissible thyroid burden. The maximum measured thyroid contamination is 24 kBq (650 nCi). The uptakes were determined by comparison with a standard curve obtained by placing various calibrated standard sources of 125I in a thyroid neck phantom. The paper also describes the set up of quality controlled counting conditions, with high sensitivity, precision, accuracy and stable detector efficiency, by adaptation of an old equipment to this purpose. Calculated 125I effective half-lives for five individuals ranged between 31.7 and 47.0 d, the average being 39.4 +/- 6.1 d.

  View details for DOI 10.1097/00004032-198809000-00001

  View details for PubMedID 3170204