Dr. Church graduated summa cum laude from Northwestern University with degrees in psychology and music composition. He earned his medical doctorate at the University of Pennsylvania where he was a Twenty-first Century Scholar. He completed his neurological surgery residency at Penn State where he also completed a neuroendovascular fellowship in 2016. He was neurosurgery registrar at Sir Charles Gairdner Hospital in Perth, Australia 2016-17 and chief resident at Penn State 2017-18. He is currently cerebrovascular neurosurgery fellow at Stanford Medicine. His clinical and research interests include cerebrovascular and endovascular neurosurgery, evidence based medicine, and medical ethics. He has numerous publications and awards including Phi Beta Kappa 2003 and Alpha Omega Alpha 2013.
Clinical Instructor, Neurosurgery
Number needed to treat for stroke thrombectomy based on a systematic review and meta-analysis.
Clinical neurology and neurosurgery
2017; 156: 83-88
The positive results of recent clinical trials examining endovascular treatment of acute stroke were the culmination of nearly two decades of studies of endovascular stroke treatment. We systematically reviewed this body of work, evaluated the strength of evidence, and performed a meta-analysis to define the clinical impact of these investigations. Terms were entered into search engines in a systematic fashion. Articles were reviewed independently by study authors, graded for level of evidence, and combined in a meta-analysis. The overall body of evidence was evaluated using GRADE criteria. Our search yielded 948 articles. Twenty-five met predefined inclusion criteria. We identified 12 grade I, 1 grade II, 5 grade III, and 7 grade IV studies (κ=0.86). Meta-analysis for independence at 90days showed a benefit of endovascular treatment (grade I studies OR 1.58 [1.20-2.07]). When limiting the analysis to studies using stent retriever, the OR increased to 2.44 (1.77-3.36). The number needed to treat (NNT) was 8. Endovascular treatment was not associated with increased symptomatic intracranial hemorrhage, and forgoing endovascular treatment was associated with death at 90 days. The quality of evidence according to GRADE criteria was "moderate." In summary, we found impressive evidence for a benefit of endovascular treatment of acute stroke, particularly when using stent retriever devices. Our meta-analysis is unique in that it includes all studies related to this topic and defines the clinical impact of the data, providing NNT. We show that thrombectomy is among the most effective stroke treatments currently available.
View details for DOI 10.1016/j.clineuro.2017.03.005
View details for PubMedID 28359980
- Journal Club: Outpatient Cervical and Lumbar Spine Surgery Is Feasible and Safe: A Consecutive Single Center Series of 1449 Patients NEUROSURGERY 2016; 79 (5): 765-767
Association of the Extent of Resection With Survival in Glioblastoma A Systematic Review and Meta-analysis
2016; 2 (11): 1460-1469
Glioblastoma multiforme (GBM) remains almost invariably fatal despite optimal surgical and medical therapy. The association between the extent of tumor resection (EOR) and outcome remains undefined, notwithstanding many relevant studies.To determine whether greater EOR is associated with improved 1- and 2-year overall survival and 6-month and 1-year progression-free survival in patients with GBM.Pubmed, CINAHL, and Web of Science (January 1, 1966, to December 1, 2015) were systematically reviewed with librarian guidance. Additional articles were included after consultation with experts and evaluation of bibliographies. Articles were collected from January 15 to December 1, 2015.Studies of adult patients with newly diagnosed supratentorial GBM comparing various EOR and presenting objective overall or progression-free survival data were included. Pediatric studies were excluded.Data were extracted from the text of articles or the Kaplan-Meier curves independently by investigators who were blinded to each other's results. Data were analyzed to assess mortality after gross total resection (GTR), subtotal resection (STR), and biopsy. The body of evidence was evaluated according to Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria and PRISMA guidelines.Relative risk (RR) for mortality at 1 and 2 years and progression at 6 months and 1 year.The search produced 37 studies suitable for inclusion (41 117 unique patients). The meta-analysis revealed decreased mortality for GTR compared with STR at 1 year (RR, 0.62; 95% CI, 0.56-0.69; P < .001; number needed to treat [NNT], 9) and 2 years (RR, 0.84; 95% CI, 0.79-0.89; P < .001; NNT, 17). The 1-year risk for mortality for STR compared with biopsy was reduced significantly (RR, 0.85; 95% CI, 0.80-0.91; P < .001). The risk for mortality was similarly decreased for any resection compared with biopsy at 1 year (RR, 0.77; 95% CI, 0.71-0.84; P < .001; NNT, 21) and 2 years (RR, 0.94; 95% CI, 0.89-1.00; P = .04; NNT, 593). The likelihood of disease progression was decreased with GTR compared with STR at 6 months (RR, 0.72; 95% CI, 0.48-1.09; P = .12; NNT, 14) and 1 year (RR, 0.66; 95% CI, 0.43-0.99; P < .001; NNT, 26). The quality of the body of evidence by the GRADE criteria was moderate to low.This analysis represents the largest systematic review and only quantitative systematic review to date performed on this subject. Compared with STR, GTR substantially improves overall and progression-free survival, but the quality of the supporting evidence is moderate to low.
View details for DOI 10.1001/jamaoncol.2016.1373
View details for PubMedID 27310651
Long-term quality of life after posterior cervical foraminotomy for radiculopathy
CLINICAL NEUROLOGY AND NEUROSURGERY
2016; 142: 22-25
Cervical radiculopathy may cause symptoms and loss of function that can lead to a significant reduction in health related quality of life (HRQOL). As part of a comprehensive review of long-term outcomes, we examined HRQOL in a large cohort of patients undergoing posterior cervical foraminotomy (FOR) for radiculopathy.338 patients who underwent FOR between 1990 and 2009 participated in a telephone interview designed to measure symptomatic and functional improvements following surgery. We also administered the EQ-5D, a standardized tool for assessing HRQOL. We analyzed this data for associations between patient and treatment characteristics, improvements in symptoms and function, and HRQOL as measured by the EQ-5D.Mean follow-up was 10.0 years. The average EQ-5D at follow-up was 0.81±0.18, and improvements in pain, weakness and function as well as ability to return to work correlated with improved EQ-5D score (p<0.0001). There was no correlation between length of follow-up and EQ-5D score (p=0.980). Additionally, there was no difference between mean EQ-5D score for soft disc versus osteophyte pathology (0.84 versus 0.81, p=0.21).These data provide evidence that FOR for cervical radiculopathy is associated with improved HRQOL at long-term follow-up. The lack of correlation between length of follow-up and HRQOL suggests that FOR is a durable treatment option. Moreover, FOR is associated with improved HRQOL whether radiculopathy is due to soft disc or osteophyte pathology.
View details for DOI 10.1016/j.clineuro.2016.01.013
View details for Web of Science ID 000372677400004
Systematic Review and Meta-analysis of Chiropractic Care and Cervical Artery Dissection: No Evidence for Causation.
2016; 8 (2)
Case reports and case control studies have suggested an association between chiropractic neck manipulation and cervical artery dissection (CAD), but a causal relationship has not been established. We evaluated the evidence related to this topic by performing a systematic review and meta-analysis of published data on chiropractic manipulation and CAD.Search terms were entered into standard search engines in a systematic fashion. The articles were reviewed by study authors, graded independently for class of evidence, and combined in a meta-analysis. The total body of evidence was evaluated according to GRADE criteria.Our search yielded 253 articles. We identified two class II and four class III studies. There were no discrepancies among article ratings (i.e., kappa=1). The meta-analysis revealed a small association between chiropractic care and dissection (OR 1.74, 95% CI 1.26-2.41). The quality of the body of evidence according to GRADE criteria was "very low."The quality of the published literature on the relationship between chiropractic manipulation and CAD is very low. Our analysis shows a small association between chiropractic neck manipulation and cervical artery dissection. This relationship may be explained by the high risk of bias and confounding in the available studies, and in particular by the known association of neck pain with CAD and with chiropractic manipulation. There is no convincing evidence to support a causal link between chiropractic manipulation and CAD. Belief in a causal link may have significant negative consequences such as numerous episodes of litigation.
View details for DOI 10.7759/cureus.498
View details for PubMedID 27014532
View details for PubMedCentralID PMC4794386
- Journal Club: Neurosurgical Practice Liability: Relative Risk by Procedure Type NEUROSURGERY 2016; 78 (2): 306-308
Clinical and histopathological outcomes in patients with SCN1A mutations undergoing surgery for epilepsy
JOURNAL OF NEUROSURGERY-PEDIATRICS
2015; 16 (6): 668-674
Mutations in the sodium channel alpha 1 subunit gene (SCN1A) have been associated with a wide range of epilepsy phenotypes including Dravet syndrome. There currently exist few histopathological and surgical outcome reports in patients with this disease. In this case series, the authors describe the clinical features, surgical pathology, and outcomes in 6 patients with SCN1A mutations and refractory epilepsy who underwent focal cortical resection prior to uncovering the genetic basis of their epilepsy.Medical records of SCN1A mutation-positive children with treatment-resistant epilepsy who had undergone resective epilepsy surgery were reviewed retrospectively. Surgical pathology specimens were reviewed.All 6 patients identified carried diagnoses of intractable epilepsy with mixed seizure types. Age at surgery ranged from 18 months to 20 years. Seizures were refractory to surgery in every case. Surgical histopathology showed evidence of subtle cortical dysplasia in 4 of 6 patients, with more neurons in the molecular layer of the cortex and white matter.Cortical resection is unlikely to be beneficial in these children due to the genetic defect and the unexpected neuropathological finding of mild diffuse malformations of cortical development. Together, these findings suggest a diffuse pathophysiological mechanism of the patients' epilepsy which will not respond to focal resective surgery.
View details for DOI 10.3171/2015.5.PEDS14551
View details for Web of Science ID 000365372300008
View details for PubMedID 26339958
- Journal Club: The Impact of Body Mass Index on Hospital Stay and Complications After Spinal Fusion NEUROSURGERY 2014; 75 (5): 599-601
- Journal Club: National Variability in Intracranial Pressure Monitoring and Craniotomy for Children With Moderate to Severe Traumatic Brian Injury NEUROSURGERY 2014; 75 (2): 191-193
- Journal club: Magnetic resonance imaging-guided focused laser interstitial thermal therapy for intracranial lesions: single-institution series. Neurosurgery 2014; 74 (5): 562-564
- The epidemiology of admissions of nontraumatic subarachnoid hemorrhage in the United States. Neurosurgery 2014; 74 (2): 227-229
Cervical laminoforaminotomy for radiculopathy: Symptomatic and functional outcomes in a large cohort with long-term follow-up.
Surgical neurology international
2014; 5: S536-43
The efficacy and safety of cervical laminoforaminotomy (FOR) in the treatment of cervical radiculopathy has been demonstrated in several series with follow-up less than a decade. However, there is little data analyzing the relative effectiveness of FOR for radiculopathy due to soft disc versus osteophyte disease. In the present study, we review our experience with FOR in a single-center cohort, with long-term follow-up.We examined the charts of patients who underwent 1085 FORs between 1990 and 2009. A cohort of these patients participated in a telephone interview designed to assess improvement in symptoms and function.A total of 338 interviews were completed with a mean follow-up of 10 years. Approximately 90% of interviewees reported improved pain, weakness, or function following FOR. Ninety-three percent of patients were able to return to work after FOR. The overall complication rate was 3.3%, and the rate of recurrent radiculopathy requiring surgery was 6.2%. Soft disc subtypes compared to osteophyte disease by operative report were associated with improved symptoms (P < 0.05). The operative report of these pathologic subtypes was associated with the preoperative magnetic resonance imaging (MRI) interpretation (P < 0.001).These results suggest that FOR is a highly effective surgical treatment for cervical radiculopathy with a low incidence of complications. Radiculopathy due to soft disc subtypes may be associated with a better prognosis compared to osteophyte disease, although osteophyte disease remains an excellent indication for FOR.
View details for DOI 10.4103/2152-7806.148029
View details for PubMedID 25593773
View details for PubMedCentralID PMC4287901
- Journal Club: The Impact of Provider Volume on the Outcomes After Surgery for Lumbar Spinal Stenosis NEUROSURGERY 2013; 72 (2): E314-E317
Decision analysis of treatment options for vestibular schwannoma Clinical article
JOURNAL OF NEUROSURGERY
2011; 114 (2): 400-413
Widespread use of MR imaging has contributed to the more frequent diagnosis of vestibular schwannomas (VSs). These tumors represent 10% of primary adult intracranial neoplasms, and if they are symptomatic, they usually present with hearing loss and tinnitus. Currently, there are 3 treatment options for quality of life (QOL): wait and scan, microsurgery, and radiosurgery. In this paper, the authors' purpose is to determine which treatment modality yields the highest QOL at 5- and 10-year follow-up, considering the likelihood of recurrence and various complications.The MEDLINE, Embase, and Cochrane online databases were searched for English-language articles published between 1990 and June 2008, containing key words relating to VS. Data were pooled to calculate the prevalence of treatment complications, tumor recurrence, and QOL with various complications. For parameters in which incidence varied with time of follow-up, the authors used meta-regression to determine the mean prevalence rates at a specified length of follow-up. A decision-analytical model was constructed to compare 5- and 10-year outcomes for a patient with a unilateral tumor and partially intact hearing. The 3 treatment options, wait and scan, microsurgery, and radiosurgery, were compared.After screening more than 2500 abstracts, the authors ultimately included 113 articles in this analysis. Recurrence, complication rates, and onset of complication varied with the treatment chosen. The relative QOL at the 5-year follow-up was 0.898 of normal for wait and scan, 0.953 for microsurgery, and 0.97 for radiosurgery. These differences are significant (p < 0.0052). Data were too scarce at the 10-year follow-up to calculate significant differences between the microsurgery and radiosurgery strategies.At 5 years, patients treated with radiosurgery have an overall better QOL than those treated with either microsurgery or those investigated further with serial imaging. The authors found that the complications associated with wait-and-scan and microsurgery treatment strategies negatively impacted patient lives more than the complications from radiosurgery. One limitation of this study is that the 10-year follow-up data were too limited to analyze, and more studies are needed to determine if the authors' results are still consistent at 10 years.
View details for DOI 10.3171/2010.3.JNS091802
View details for Web of Science ID 000286548500021
View details for PubMedID 20397894
Development of and psychometric testing for the Brief Pain Inventory-Facial in patients with facial pain syndromes
JOURNAL OF NEUROSURGERY
2010; 113 (3): 516-523
Outcomes in clinical trials on trigeminal pain therapies require instruments with demonstrated reliability and validity. The authors evaluated the Brief Pain Inventory (BPI) in its existing form plus an additional 7 facial-specific items in patients referred to a single neurosurgeon for a diagnosis of facial pain. The complete 18-item instrument is referred to as the BPI-Facial.This study was a cross-sectional analysis of patients who completed the BPI-Facial. The diagnosis of classic versus atypical trigeminal neuralgia (TN) was made before analyzing the questionnaire results. A hypothesis-driven factor analysis was used to determine the principal components of the questionnaire. Item reliability and questionnaire validity were tested for these specific constructs.Data from 156 patients were analyzed, including 114 patients (73%) with classic and 42 (27%) with atypical TN. Using orthomax rotation factor analysis, 3 factors with an eigenvalue > 1.0 were identified-pain intensity, interference with general activities, and facial-specific pain interference-accounting for 97.6% of the observed item variance. Retention of the 3 factors was confirmed via a Cattell scree plot. Internal reliability was demonstrated by calculating Cronbach's alpha: 0.86 for pain intensity, 0.89 for interference with general activities, 0.95 for facial-specific pain interference, and 0.94 for the entire instrument. Initial validity of the BPI-Facial instrument was supported by the detection of statistically significant differences between patients with classic versus atypical pain. Patients with atypical TN rated their facial pain as more intense (atypical 6.24 vs classic 5.03, p = 0.013) and as having greater interference in general activities (atypical 6.94 vs classic 5.43, p = 0.0033). Both groups expressed high levels of facial-specific pain interference (atypical 6.34 vs classic 5.95, p = 0.527).The BPI-Facial is a rigorous measure of facial pain in patients with TN and appears to have sound psychometric properties and is responsive to differences between classic and atypical TN. Future studies must assess the instrument's test-retest reliability, validity in additional populations, and responsiveness with respect to changes in patient outcomes following neurosurgical interventions and medical therapies.
View details for DOI 10.3171/2010.1.JNS09669
View details for Web of Science ID 000281111100013
View details for PubMedID 20151778
Intracerebral microdialysis during deep brain stimulation surgery
JOURNAL OF NEUROSCIENCE METHODS
2010; 190 (1): 106-111
This report describes the use of microdialysis in conjunction with deep brain stimulation (DBS) surgery to assess extracellular levels of neurotransmitters within the human basal ganglia (BG). Electrical stimulation of the subthalamic nucleus (STN) is an efficacious treatment for advanced Parkinson's disease, yet the mechanisms of STN DBS remain poorly understood. Measurement of neurotransmitter levels within the BG may provide insight into mechanisms of DBS, but such an approach presents technical challenges.After microelectrode recordings confirmed location of STN, a custom microdialysis guide cannula was inserted. A CMA (Stockholm, Sweden) microdialysis probe was then positioned to the same depth as the microrecording electrode in STN or 2mm inferiorly to record in the substantia nigra. The catheter was perfused at a rate of 2.0 microL/min with a sterile mock CSF solution and samples of extracellular fluid were collected at regular intervals. Dialysate samples were analyzed using high-pressure liquid chromatography (HPLC) detection procedures for quantitation of glutamate, gamma-aminobutyric acid (GABA), and dopamine.Levels of neurotransmitters were reliably identified in dialysate samples using HPLC. By monitoring concentrations of glutamate, GABA and dopamine, we were able to demonstrate what seemed to be a steady state baseline within approximately 30 min.Microdialysis during DBS surgery is a feasible method for assessing levels of glutamate, GABA and dopamine within the human BG. Obtaining a steady state baseline of neurotransmitter levels appears feasible, thus making future studies of intraoperative microdialysis during DBS meaningful.
View details for DOI 10.1016/j.jneumeth.2010.04.013
View details for Web of Science ID 000279888800015
View details for PubMedID 20416339
SUBCUTANEOUS HEPARIN FOR PROPHYLAXIS OF VENOUS THROMBOEMBOLISM IN DEEP BRAIN STIMULATION SURGERY: EVIDENCE FROM A DECISION ANALYSIS
2009; 65 (2): 276-280
The addition of subcutaneous heparin (SQH) to mechanical prophylaxis for venous thromboembolism (VTE) involves a balance between the benefit of greater protection from VTE and the added risk of intracranial hemorrhage. There is evidence that the hemorrhage risk outweighs the benefits for patients undergoing craniotomy. We investigated the safety of SQH in patients undergoing deep brain stimulation (DBS) surgery.A retrospective analysis was performed of all patients with movement disorders (n = 254) undergoing DBS surgery at our institution from 2003 to 2007. Before September 2005, none of the patients undergoing DBS received SQH (non-SQH group) (n = 121). Thereafter, all patients were administered SQH perioperatively (SQH group) (n = 133). All patients wore graduated compression stockings and pneumatic compression boots postoperatively in bed. A postoperative brain magnetic resonance imaging scan was obtained on the day of surgery.Five (3.8%) of 133 SQH patients and 1 (0.8%) of 121 non-SQH patients developed asymptomatic intracranial hemorrhage. None of the SQH patients developed clinically significant VTE, whereas 3 (2.5%) non-SQH patients developed VTE (1 deep venous thrombosis, 2 pulmonary embolisms). Using a decision-analysis model, we have shown that the use of SQH plus mechanical prophylaxis together yielded outcomes at least as good as mechanical prophylaxis alone.Our findings suggest that SQH for VTE prophylaxis in patients with movement disorders undergoing DBS surgery is safe. SQH protects against VTE in this patient population and merits further investigation.
View details for DOI 10.1227/01.NEU.0000348297.92052.E0
View details for Web of Science ID 000268523200013
View details for PubMedID 19625905
Feasibility of an Operational Standardized Checklist for Movement Disorder Surgery A Pilot Study
STEREOTACTIC AND FUNCTIONAL NEUROSURGERY
2009; 87 (2): 94-100
Despite the clinical success of deep brain stimulation (DBS), it remains to be elucidated where within the work process the surgical result could diverge from the surgical plan. We sought to determine this. We implemented a standardized checklist to detect and remediate procedural errors. A consecutive series of 13 patients was studied. Revisions, explantations and thermal lesions were excluded. We tabulated the number and type of errors that could occur when implementing a surgical plan. Errors were categorized as minor or major. The elapsed time was also assessed. A mean of two errors per case were identified: 1.15 major errors/case and 0.85 minor errors per case. The total number of errors identified per case did not change significantly over the course of the series. Time to complete the checklist decreased monotonically from 4 min 5 s to 1 min 10 s. The checklist applied in this scenario is a useful tool to identify and remediate errors during DBS, adding minimal additional operative time and consistently identifying errors.
View details for DOI 10.1159/000202975
View details for Web of Science ID 000264025400004
View details for PubMedID 19223695