All Publications

  • CDC42BPA::BRAF represents a novel fusion in desmoplastic infantile ganglioglioma/desmoplastic infantile astrocytoma. Neuro-oncology advances Barros Guinle, M. I., Nirschl, J. J., Xing, Y. L., Nettnin, E. A., Arana, S., Feng, Z. P., Nasajpour, E., Pronina, A., Garcia, C. A., Grant, G. A., Vogel, H., Yeom, K. W., Prolo, L. M., Petritsch, C. K. 2024; 6 (1): vdae050

    View details for DOI 10.1093/noajnl/vdae050

    View details for PubMedID 38741773

    View details for PubMedCentralID PMC11089409

  • Expanding eligibility for intracranial electroencephalography using Dexmedetomidine Hydrochloride in children with behavioral dyscontrol. Epilepsy & behavior : E&B Johnstone, T., Isabel Barros Guinle, M., Grant, G. A., Porter, B. E. 2023; 150: 109541


    Invasive intracranial electroencephalography (IEEG) is advantageous for identifying epileptogenic foci in pediatric patients with medically intractable epilepsy. Patients with behavioral challenges due to autism, intellectual disabilities, and hyperactivity have greater difficulty tolerating prolonged IEEG recording and risk injuring themselves or others. There is a need for therapies that increase the safety of IEEG but do not interfere with IEEG recording or prolong hospitalization. Dexmedetomidine Hydrochloride's (DH) use has been reported to improve safety in patients with behavioral challenges during routine surface EEG recording but has not been characterized during IEEG. Here we evaluated DH administration in pediatric patients undergoing IEEG to assess its safety and impact on the IEEG recordings.A retrospective review identified all pediatric patients undergoing IEEG between January 2016 and September 2022. Patient demographics, DH administration, DH dose, hospital duration, and IEEG seizure data were analyzed. The number of seizures recorded for each patient was divided by the days each patient was monitored with IEEG. The total number of seizures, as well as seizures per day, were compared between DH and non-DH patients via summary statistics, multivariable linear regression, and univariate analysis. Other data were compared across groups with univariate statistics.Eighty-four pediatric patients met the inclusion criteria. Eighteen (21.4 %) received DH treatment during their IEEG recording. There were no statistical differences between the DH and non-DH groups' demographic data, length of hospital stays, or seizure burden. Non-DH patients had a median age of 12.0 years (interquartile range: 7.25-15.00), while DH-receiving patients had a median age of 8.0 years old (interquartile range: 3.00-13.50) (p = 0.07). The non-DH cohort was 57.6 % male, and the DH cohort was 50.0 % male (p = 0.76). The median length of IEEG recordings was 5.0 days (interquartile range: 4.00-6.25) for DH patients versus 6.0 days (interquartile range: 4.00-8.00) for non-DH patients (p = 0.25). Median total seizures recorded in the non-DH group was 8.0 (interquartile range: 5.00-13.25) versus 15.0 in the DH group (interquartile range: 5.00-22.25) (p = 0.33). Median total seizures per day of IEEG monitoring were comparable across groups: 1.50 (interquartile range: 0.65-3.17) for non-DH patients compared to 2.83 (interquartile range: 0.89-4.35) (p = 0.25) for those who received DH. Lastly, non-DH patients were hospitalized for a median of 8.0 days (interquartile range: 6.00-11.25), while DH patients had a median length of stay of 7.00 days (interquartile range: 5.00-8.25) (p = 0.27). No adverse events were reported because of DH administration.Administration of DH was not associated with adverse events. Additionally, the frequency of seizures captured on the IEEG, as well as the duration of hospitalization, were not significantly different between patients receiving and not receiving DH during IEEG. Incorporating DH into the management of patients with behavioral dyscontrol and intractable epilepsy may expand the use of IEEG to patients who previously could not tolerate it, improve safety, and preserve epileptic activity during the recording period.

    View details for DOI 10.1016/j.yebeh.2023.109541

    View details for PubMedID 38035536

  • Approach, complications, and outcomes for 37 consecutive pediatric patients undergoing laser ablation for medically refractory epilepsy at Stanford Children's Health. Journal of neurosurgery. Pediatrics Barros Guinle, M. I., Johnstone, T., Li, D., Kaur, H., Porter, B. E., Grant, G. A. 2023: 1-11


    OBJECTIVE: The objective of this study was to better understand the safety and efficacy of laser interstitial thermal therapy (LITT) for children with medically refractory epilepsy.METHODS: Thirty-seven consecutive pediatric epilepsy patients at a single pediatric center who underwent LITT ablation of epileptogenic foci between May 2017 and December 2021 were retrospectively reviewed. Patient demographics, medication use, seizure frequency, prior surgical interventions, procedural details, and pre- and postoperative seizure history were analyzed.RESULTS: Thirty-seven pediatric patients (24 male, 13 female) with severe medically refractory epilepsy were included; all underwent stereo-electroencephalography (SEEG) prior to LITT. The SEEG electrode placement was based on the preoperative workup and tailored to each patient by the epileptologist and neurosurgeons working together to identify the epileptic network and hopefully quiet borders. Seizure onset was at a mean age of 2.70 ± 2.82 years (range 0.25-12 years), and the mean age at the time of LITT was 9.46 ± 5.08 years (range 2.41-17.86 years). Epilepsy was lesional in 23 patients (18 tuberous sclerosis, 4 focal cortical dysplasia, 1 gliosis) and nonlesional in 14. Eighteen patients had prior surgical interventions including open resections (n = 13: 11 single and 2 multiple), LITT (n = 4), or both (n = 1). LITT targeted a region adjacent to the previous target in 5 cases. The median number of lasers placed during the procedure was 3 (range 1-5). Complications occurred in 14 (37.8%) cases, only 3 (8.11%) of which resulted in a permanent deficit: 1 venous hemorrhage requiring evacuation following laser ablation, 1 aseptic meningitis, 2 immediate postoperative seizures, and 10 neurological deficits (7 transient and 3 permanent). Postoperatively, 22 (59.5%) patients were seizure free at the last follow-up (median follow-up 18.35 months, range 7.40-48.76 months), and the median modified Engel class was I (Engel class I in 22 patients, Engel class II in 2, Engel class III in 2, and Engel class IV in 11). Patients having tried a greater number of antiseizure medications before LITT were less likely to achieve seizure improvement (p = 0.046) or freedom (p = 0.017). Seizure improvement following LITT was associated with a shorter duration of epilepsy prior to LITT (p = 0.044), although postoperative seizure freedom was not associated with a shorter epilepsy duration (p = 0.667). Caregivers reported postoperative neurocognitive improvement in 17 (45.9%) patients.CONCLUSIONS: In this large single-institution cohort of pediatric patients with medically refractory seizures due to various etiologies, LITT was a relatively safe and effective surgical approach for seizure reduction and seizure freedom at 1 year of follow-up.

    View details for DOI 10.3171/2023.8.PEDS23158

    View details for PubMedID 37922561

  • The Role of Stress, Trauma, and Negative Affect in Alcohol Misuse and Alcohol Use Disorder in Women. Alcohol research : current reviews Guinle, M. I., Sinha, R. 2020; 40 (2): 05


    Recent evidence indicates that the United States is facing a public health crisis of alcohol misuse and alcohol use disorder (AUD), which has been fueled in part by dramatic rises in binge and heavy drinking and prevalence of AUD in women. Historically, alcohol misuse and AUD have been more prevalent in men than in women. However, recent evidence on data from the past decade shows increases in AUD prevalence rates that are associated with substantially higher binge and heavy drinking and AUD prevalence in women compared to men. This paper first addresses the key roles of stress, trauma, childhood maltreatment, negative affect, and mood and anxiety disorders; sex differences in the presentation of these psychosocial and psychological factors; and their contributions to alcohol misuse, escalation to binge and heavy drinking, and transition to AUD in women. Also examined are potential central and peripheral biological mechanisms by which stressors and traumatic experiences, as well as chronic stress states-including depression and anxiety-may facilitate differential pathways to alcohol misuse, escalation, and transition to AUD in women. Finally, this paper discusses major gaps in the literature on sex differences in these areas as well as the need for greater research on sex-specific pathways to alcohol misuse and transition to AUD, so as to support a more comprehensive understanding of AUD etiology and for the development of new strategies for prevention and treatment of alcohol misuse and AUD in women.

    View details for DOI 10.35946/arcr.v40.2.05

    View details for PubMedID 32832310

    View details for PubMedCentralID PMC7431322

  • Neurosurgical Outcomes Among Non-English Speakers: A Systematic Review and a Framework for Future Research. World neurosurgery Ruiz Colon, G. D., Barros Guinle, M. I., Wu, A., Grant, G. A., Prolo, L. M. 2024


    OBJECTIVE: In 2019, 22% of adults in the United States reported speaking a language other than English at home, representing 52% growth since 2000. This diversity in languages - and resulting possible communication barriers - represents a potential challenge to effective care. In this manuscript, we summarize clinical outcomes and healthcare utilization patterns of adult and pediatric neurosurgical patients who are non-English primary language speakers (NEPLS).METHODS: We systematically queried five databases from inception through October 2022. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to identify studies for inclusion. The Newcastle-Ottawa Scale was used to assess the quality of studies. Additionally, a retrospective chart review was conducted to assess differences in postoperative communication patterns in a cohort of English and Spanish speaking patients with craniosynostosis at our institution.RESULTS: Our search yielded 442 abstracts; ten were included in the final cohort. Outcomes for 973 unique NEPLS with a neurosurgical condition were included; Spanish was the most represented language. Delivery and timing of surgical treatment was the most frequently reported metric; 75% of studies demonstrated a statistically significant delay in time to surgery or decreased likelihood for NEPLS to receive surgical treatment. Length of stay (LOS) was reported in three studies; all demonstrated that NEPLS had longer LOS.CONCLUSION: There is a paucity of literature reporting outcomes among NEPLS. It is critical to examine NEPLS patients' outcomes and experiences, as language barriers are potentially modifiable demographic factors. We present a framework that demonstrates opportunities for further research to improve quality of care.

    View details for DOI 10.1016/j.wneu.2024.02.068

    View details for PubMedID 38387790

  • Response Letter to the Editor: "Expanding eligibility for intracranial electroencephalography using dexmedetomidine hydrochloride in children with behavioral dyscontrol". Epilepsy & behavior : E&B Johnstone, T., Guinle, M. I., Grant, G. A., Porter, B. E. 2024; 153: 109657

    View details for DOI 10.1016/j.yebeh.2024.109657

    View details for PubMedID 38368786

  • Getting What You Pay For: Impact of Copayments on Physical Therapy and Opioid Initiation, Timing, and Continuation for Newly Diagnosed Low Back Pain. The spine journal : official journal of the North American Spine Society Jin, M. C., Jensen, M., Barros Guinle, M. I., Ren, A., Zhou, Z., Zygourakis, C. C., Desai, A. M., Veeravagu, A., Ratliff, J. K. 2024


    Physical therapy (PT) is an important component of low back pain (LBP) management. Despite established guidelines, heterogeneity in medical management remains common.We sought to understand how copayments impact timing and utilization of PT in newly diagnosed LBP.The IBM Watson Health MarketScan claims database was utilized in a longitudinal setting.Adult patients with LBP.The primary outcomes-of-interest were timing and overall utilization of PT services. Additional outcomes-of-interest included timing of opioid prescribing.Actual and inferred copayments based on non-PCP visit claims were used to evaluate the relationship between PT copayment and incidence of PT initiation. Multivariable regression models were used to evaluate factors influencing PT usage.Overall, 2,467,389 patients were included. PT initiation, among those with at ≥1 PT service during the year after LBP diagnosis (30.6%), occurred at a median of 8 days post-diagnosis (IQR 1-55). Among those with at least one PT encounter, incidence of subsequent PT visits was significantly lower for those with high initial PT copayments. High initial PT copayments, while inversely correlated with PT utilization, were directly correlated with subsequent opioid use (0.77 prescriptions/patient [$0 PT copayment] vs 1.07 prescriptions/patient [$50-74 PT copayment]; 1.15 prescriptions/patient [$75+ PT copayment]). Among patients with known opioid and PT copayments, higher PT copayments were correlated with faster opioid use while higher opioid copayments were correlated with faster PT use (Spearman p < 0.05). For multivariable whole-cohort analyses, incidence of PT initiation among patients with inferred copayments in the 50-75th and 75th-100th percentiles was significantly lower than those below the 50th percentile (HR=0.893 [95%CI 0.887-0.899] and HR=0.905 [95%CI 0.899-0.912], respectively).Higher PT copayments correlated with reduced PT utilization; higher PT copayments and lower opioid copayments were independent contributors to delayed PT initiation and higher opioid use. In patients covered by plans charging high PT copayments, opioid use was significantly higher. Co-pays may impact long-term adherence to PT.

    View details for DOI 10.1016/j.spinee.2024.01.008

    View details for PubMedID 38262499

  • Equipping doctors to save lives when resources are scarce Barros Guinle, M., Hansen, J. Center for Innovation in Global Health. 2024
  • Bridging Borders for Newborns: How an International Collaboration Aims to Reduce Deadly Brain Bleeds in Brazilian Babies Barros Guinle, M. Center for Innovation in Global Health. 2024
  • Review: therapeutic approaches for circadian modulation of the glioma microenvironment. Frontiers in oncology Nettnin, E. A., Nguyen, T., Arana, S., Barros Guinle, M. I., Garcia, C. A., Gibson, E. M., Prolo, L. M. 2023; 13: 1295030


    High-grade gliomas are malignant brain tumors that are characteristically hard to treat because of their nature; they grow quickly and invasively through the brain tissue and develop chemoradiation resistance in adults. There is also a distinct lack of targeted treatment options in the pediatric population for this tumor type to date. Several approaches to overcome therapeutic resistance have been explored, including targeted therapy to growth pathways (ie. EGFR and VEGF inhibitors), epigenetic modulators, and immunotherapies such as Chimeric Antigen Receptor T-cell and vaccine therapies. One new promising approach relies on the timing of chemotherapy administration based on intrinsic circadian rhythms. Recent work in glioblastoma has demonstrated temporal variations in chemosensitivity and, thus, improved survival based on treatment time of day. This may be due to intrinsic rhythms of the glioma cells, permeability of the blood brain barrier to chemotherapy agents, the tumor immune microenvironment, or another unknown mechanism. We review the literature to discuss chronotherapeutic approaches to high-grade glioma treatment, circadian regulation of the immune system and tumor microenvironment in gliomas. We further discuss how these two areas may be combined to temporally regulate and/or improve the effectiveness of immunotherapies.

    View details for DOI 10.3389/fonc.2023.1295030

    View details for PubMedID 38173841

    View details for PubMedCentralID PMC10762863

  • CHEK2 mutations in pediatric brain tumors. Neuro-oncology advances Tlais, D., Barros Guinle, M. I., Wheeler, J. R., Prolo, L. M., Vogel, H., Partap, S. 2023; 5 (1): vdad038

    View details for DOI 10.1093/noajnl/vdad038

    View details for PubMedID 37207118

    View details for PubMedCentralID PMC10191190

  • Pediatric Epilepsy Outcomes After Laser Ablation: An Institutional Cohort Analysis Li, D., Guinle, M., Johnstone, T., Kaur, H., Porter, B., Grant, G. A. LIPPINCOTT WILLIAMS & WILKINS. 2023: 37
  • Opioid usage in lumbar disc herniation patients with nonsurgical, early, and late surgical treatments. World neurosurgery Zhou, Z., Jin, M. C., Jensen, M. R., Barros Guinle, M. I., Ren, A., Agarwal, A. A., Leaston, J., Ratliff, J. K. 2023


    Assess opioid usage in surgical and non-surgical patients with lumbar disc herniation receiving different treatment approaches and timing.Individuals with newly diagnosed lumbar intervertebral disc without myelopathy were queried from Optum Clinformatics DataMart. Patients were categorized into 3 cohorts: nonsurgical, early surgery, and late surgery. Early surgery cohort patients had surgery within 30-days post-diagnosis; late surgery cohort patients had surgery after 30 days but before 1-year post-diagnosis. The index date was defined as the diagnosis date for nonsurgical patients, and the initial surgery date for surgical patients. The primary outcome was the average daily opioid morphine milligram equivalent (MME) prescribed. Additional outcomes included the percentage of opioid-using patients and cumulative opioid burden.A total of 573,082 patients met inclusion criteria: 533,226 patients received nonsurgical treatments, 22,312 patients received early surgery, and 17,544 patients received late surgery. Both surgical cohorts experienced a "post-surgical hump" of opioid usage, which then sharply declined and gradually plateaued, with daily opioid MME consistently lower in the early as opposed to late surgery cohort. The early surgery cohort also consistently had a lower prevalence of opioid-using patients than the late surgery cohort. Patients receiving nonsurgical demonstrated the highest one-year post-index cumulative opioid burden, and the early surgery cohort consistently had lower cumulative opioid MME than the late surgery cohort.Early surgery in lumbar disc herniation patients is associated with lower long-term average daily MME, incidence of opioid use, and one-year cumulative MME burden compared to nonsurgical and late surgery treatment approaches.

    View details for DOI 10.1016/j.wneu.2023.02.029

    View details for PubMedID 36775237

  • Stanford Medicine Researchers Propose New Guidelines for Tuberculosis Prevention in Prisons Barros Guinle, M. Center for Innovation in Global Health. 2023


    Barros Guinle, Maria Isabel. “Stanford Medicine Researchers Propose New Guidelines for Tuberculosis Prevention in Prisons.” Global Health, 9 Oct. 2023,

  • Clinically relevant concurrent BRAF and MEK inhibition alters differentiation states and sensitizes BRAF V600E-mutated high-grade gliomas to immune checkpoint blockade Park, J., Grossauer, S., Wang, W., Xing, Y., Koeck, K., Garcia, C. A., Nasajpour, E., Wilson, C., Lancero, H., Harter, P. N., Filipski, K., Daynac, M., Meyer, L., Barros Guinle, M., Monje, M., Vogel, H., Lim, M., Prolo, L. M., Grant, G. A., Petritsch, C. K. bioRxiv. 2023
  • Getting into the rhythm and challenging my inherent fear of failure Barros Guinle, M. Swarthmore College Bulletin. 2023
  • CHEK2 mutations in pediatric brain tumors Neuro-Oncology Advances Tlais, D., Barros Guinle, M., Wheeler, J., Prolo, L. M., Vogel, H., Partap, S. 2023; 5 (1)

    View details for DOI 10.1093/noajnl/vdad038

  • Ballet and Medicine Barros Guinle, M. CLOSLER. 2023 ; Lifelong Learning in Clinical Experience
  • Health Care Resource Utilization in Management of Opioid-Naive Patients With Newly Diagnosed Neck Pain. JAMA network open Jin, M. C., Jensen, M., Zhou, Z., Rodrigues, A., Ren, A., Barros Guinle, M. I., Veeravagu, A., Zygourakis, C. C., Desai, A. M., Ratliff, J. K. 2022; 5 (7): e2222062


    Importance: Research has uncovered heterogeneity and inefficiencies in the management of idiopathic low back pain, but few studies have examined longitudinal care patterns following newly diagnosed neck pain.Objective: To understand health care utilization in patients with new-onset idiopathic neck pain.Design, Setting, and Participants: This cross-sectional study used nationally sourced longitudinal data from the IBM Watson Health MarketScan claims database (2007-2016). Participants included adult patients with newly diagnosed neck pain, no recent opioid use, and at least 1 year of continuous postdiagnosis follow-up. Exclusion criteria included prior or concomitant diagnosis of traumatic cervical disc dislocation, vertebral fractures, myelopathy, and/or cancer. Only patients with at least 1 year of prediagnosis lookback were included. Data analysis was performed from January 2021 to January 2022.Main Outcomes and Measures: The primary outcome of interest was 1-year postdiagnosis health care expenditures, including costs, opioid use, and health care service utilization. Early services were those received within 30 days of diagnosis. Multivariable regression models and regression-adjusted statistics were used.Results: In total, 679 030 patients (310 665 men [45.6%]) met the inclusion criteria, of whom 7858 (1.2%) underwent surgery within 1 year of diagnosis. The mean (SD) age was 44.62 (14.87) years among nonsurgical patients and 49.69 (9.53) years among surgical patients. Adjusting for demographics and comorbidities, 1-year regression-adjusted health care costs were $24 267.55 per surgical patient and $515.69 per nonsurgical patient. Across all health care services, $95 379 949 was accounted for by nonsurgical patients undergoing early imaging who did not receive any additional conservative therapy or epidural steroid injections, for a mean (SD) of $477.53 ($1375.60) per patient and median (IQR) of $120.60 ($20.70-$452.37) per patient. On average, patients not undergoing surgery, physical therapy, chiropractic manipulative therapy, or epidural steroid injection, who underwent either early advanced imaging (magnetic resonance imaging or computed tomography) or both early advanced and radiographic imaging, accumulated significantly elevated health care costs ($850.69 and $1181.67, respectively). Early conservative therapy was independently associated with 24.8% (95% CI, 23.5%-26.2%) lower health care costs.Conclusions and Relevance: In this cross-sectional study, early imaging without subsequent intervention was associated with significantly increased health care spending among patients with newly diagnosed idiopathic neck pain. Early conservative therapy was associated with lower costs, even with increased frequency of therapeutic services, and may have reduced long-term care inefficiency.

    View details for DOI 10.1001/jamanetworkopen.2022.22062

    View details for PubMedID 35816312

  • Stress Interacts with Heart Rate Variability to Predict Child Dysregulation in Parents with Obesity Fogelman, N., Schwartz, J., Guinle, M., Lartigue, S., Jastreboff, A., Silverman, W., Sinha, R. WILEY. 2021: 165-166
  • Individuals Higher in Eating Restraint Show Heightened Physiological Arousal to Food Images Journal of Food Research Barros Guinle, M., Yudien, M. A., Norris, C. J. 2021

    View details for DOI 10.5539/jfr.v10n3p11

  • Connective Core Structures in Cognitive Networks: The Role of Hubs ENTROPY Baltazar, C., Barros Guinle, M., Caron, C., Amaro, E., Machado, B. 2019; 21 (10)

    View details for DOI 10.3390/e21100961

    View details for Web of Science ID 000495094000043