
Maria Isabel (Bel) Barros Guinle
MD Student, expected graduation Winter 2026
Other Tech - Graduate, SoM Office of Student Services
All Publications
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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
2023: 1-11
Abstract
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
- Clinically relevant concurrent BRAF and MEK inhibition alters differentiation states and sensitizes BRAF V600E-mutated high-grade gliomas to immune checkpoint blockade bioRxiv. 2023
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The Role of Stress, Trauma, and Negative Affect in Alcohol Misuse and Alcohol Use Disorder in Women.
Alcohol research : current reviews
2020; 40 (2): 05
Abstract
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
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Expanding eligibility for intracranial electroencephalography using Dexmedetomidine Hydrochloride in children with behavioral dyscontrol.
Epilepsy & behavior : E&B
2023; 150: 109541
Abstract
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
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CHEK2 mutations in pediatric brain tumors.
Neuro-oncology advances
2023; 5 (1): vdad038
View details for DOI 10.1093/noajnl/vdad038
View details for PubMedID 37207118
View details for PubMedCentralID PMC10191190
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Pediatric Epilepsy Outcomes After Laser Ablation: An Institutional Cohort Analysis
LIPPINCOTT WILLIAMS & WILKINS. 2023: 37
View details for Web of Science ID 001043164400047
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Opioid usage in lumbar disc herniation patients with nonsurgical, early, and late surgical treatments.
World neurosurgery
2023
Abstract
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
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Stanford Medicine Researchers Propose New Guidelines for Tuberculosis Prevention in Prisons
Center for Innovation in Global Health.
2023
Abstract
Barros Guinle, Maria Isabel. “Stanford Medicine Researchers Propose New Guidelines for Tuberculosis Prevention in Prisons.” Global Health, 9 Oct. 2023, globalhealth.stanford.edu/vulnerable-populations/stanford-medicine-researchers-propose-new-guidelines-for-tuberculosis-prevention-in-prisons.html/#.
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NOVEL VALIDATED PATIENT-DERIVED MODELS OF A RECTAL CANCER BRAIN METASTASIS
2023 SNO/ASCO Conference
2023
View details for DOI 10.1093/noajnl/vdad070.013 PMCID: PMC10402389
- Getting into the rhythm and challenging my inherent fear of failure Swarthmore College Bulletin. 2023
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CHEK2 mutations in pediatric brain tumors
Neuro-Oncology Advances
2023; 5 (1)
View details for DOI 10.1093/noajnl/vdad038
- Ballet and Medicine CLOSLER. 2023 ; Lifelong Learning in Clinical Experience
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Health Care Resource Utilization in Management of Opioid-Naive Patients With Newly Diagnosed Neck Pain.
JAMA network open
2022; 5 (7): e2222062
Abstract
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
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Stress Interacts with Heart Rate Variability to Predict Child Dysregulation in Parents with Obesity
WILEY. 2021: 165-166
View details for Web of Science ID 000727052100398
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Individuals Higher in Eating Restraint Show Heightened Physiological Arousal to Food Images
Journal of Food Research
2021
View details for DOI 10.5539/jfr.v10n3p11
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Connective Core Structures in Cognitive Networks: The Role of Hubs
ENTROPY
2019; 21 (10)
View details for DOI 10.3390/e21100961
View details for Web of Science ID 000495094000043
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VIEWING FOOD IMAGES GENERATES AROUSAL IN HIGH EATING RESTRAINT INDIVIDUALS: EVIDENCE FROM SELF-REPORTS AND SKIN CONDUCTANCE
WILEY. 2019: S126
View details for Web of Science ID 000494324000501