Intraoperative neuromonitoring potentials and evidence of preserved neuronal circuitry below the anatomical and functional level in patients with complex spinal dysraphism undergoing detethering reoperations.

OBJECTIVE: Spina bifida represents one of the most common birth defects, occurring in approximately 1-2 children per 1000 live births worldwide. The functional level of patients with spina bifida is highly variable and believed to be correlated with the anatomical level of the lesion. The variable clinical picture is well established, but the correlation with anatomical level and intraoperative neuromonitoring (IONM) data has not been investigated. Furthermore, the potential for preserving function beyond the apparent clinical level has also not been investigated. The objective of this research was to determine the presence and level of intraoperative transcranial motor evoked potential (tcMEP) and triggered electromyography (tEMG) responses, and the association of these responses with preoperative clinical function and radiographic data in pediatric cases of complex tethered cord release reoperations. METHODS: A single-center retrospective review of pediatric patients with complex spinal dysraphism undergoing detethering reoperations was conducted. Preoperative demographic and clinical data, including the radiographic and clinical level of dysraphism, were collected. IONM, including tcMEPs and tEMG responses, were obtained and compared with preoperative clinical data. Descriptive analysis was performed, by patient for demographics and by case for surgeries performed. RESULTS: In 100% of 21 cases of complex detethering reoperations, representing 20 patients, intraoperative tcMEPs could be generated at (4.8%) or below (95.2%) the level of clinical function. Compared with the preoperative clinical examination, 5 cases (23.8%) demonstrated tcMEP responses that were 1 level below the clinical function level, 11 cases (52.4%) were 2 levels below, and 4 cases (19.0%) were 3 levels below. Overall, 18 of 21 cases showed tEMG responses at or below the level of clinical function; of these, 7 cases (33%) were 1 level below and 3 (14%) were ≥ 2 levels below the clinical function level. CONCLUSIONS: The presence of positive stimulation potentials below the level of clinical function in patients with complex spinal dysraphism undergoing detethering reoperations indicates a degree of preserved neuronal connectivity. These findings suggest novel future treatment approaches for these patients, including using devices targeted to stimulation of these neurological pathways.

Deep Brain Stimulation of Bilateral Centromedian Thalamic Nuclei in Pediatric Patients with Lennox-Gastaut Syndrome: An Institutional Experience.

BACKGROUND: Surgical management of pediatric patients with nonlesional, drug-resistant epilepsy, including patients with Lennox-Gastaut syndrome (LGS), remains a challenge given the lack of resective targets in most patients and shows seizure freedom rates <50% at 5 years. The efficacy of deep brain stimulation (DBS) is less certain in children than in adults. This study examined clinical and seizure outcomes for pediatric patients with LGS undergoing DBS targeting of the centromedian thalamic nuclei (CMTN). METHODS: An institutional review board-approved retrospective analysis was performed of patients aged ≤19 years with clinical diagnosis of LGS undergoing bilateral DBS placement to the CMTN from 2020 to 2021 by a single surgeon. RESULTS: Four females and 2 males aged 6-19 years were identified. Before surgery, each child experienced at least 6 years of refractory seizures; 4 children had experienced seizures since infancy. All took antiseizure medications at the time of surgery. Five children had previous placement of a vagus nerve stimulator and 2 had a previous corpus callosotomy. The mean length of stay after DBS was 2 days. No children experienced adverse neurologic effects from implantation; the mean follow-up time was 16.3 months. Four patients had >60% reduction in seizure frequency after surgery, 1 patient experienced 10% reduction, and 1 patient showed no change. No children reported worsening seizure symptoms after surgery. CONCLUSIONS: Our study contributes to the sparse literature describing CMTN DBS for children with drug-resistant epilepsy from LGS. Our results suggest that CMTN DBS is a safe and effective therapeutic modality that should be considered as an alternative or adjuvant therapy for this challenging patient population. Further studies with larger patient populations are warranted.

A comparison of computed tomography angiography and digital subtraction angiography for the diagnosis of penetrating cerebrovascular injury: a prospective multicenter study.

OBJECTIVE: In this research, the authors sought to characterize the incidence and extent of cerebrovascular lesions after penetrating brain injury in a civilian population and to compare the diagnostic value of head computed tomography angiography (CTA) and digital subtraction angiography (DSA) in their diagnosis. METHODS: This was a prospective multicenter cohort study of patients with penetrating brain injury due to any mechanism presenting at two academic medical centers over a 3-year period (May 2020 to May 2023). All patients underwent both CTA and DSA. The sensitivity and specificity of CTA was calculated, with DSA considered the gold standard. The number of DSA studies needed to identify a lesion requiring treatment that had not been identified on CTA was also calculated. RESULTS: A total of 73 patients were included in the study, 33 of whom had at least 1 penetrating cerebrovascular injury, for an incidence of 45.2%. The injuries included 13 pseudoaneurysms, 11 major arterial occlusions, 9 dural venous sinus occlusions, 8 dural arteriovenous fistulas, and 6 carotid cavernous fistulas. The sensitivity of CTA was 36.4%, and the specificity was 85.0%. Overall, 5.6 DSA studies were needed to identify a lesion requiring treatment that had not been identified with CTA. CONCLUSIONS: Cerebrovascular injury is common after penetrating brain injury, and CTA alone is insufficient to diagnosis these injuries. Patients with penetrating brain injuries should routinely undergo DSA.

Neurosurgery Clerkships in United States Medical Schools: A Survey of Doctor of Medicine-Granting and Doctor of Osteopathic Medicine-Granting Schools.

OBJECTIVE: Exposure to neurosurgery is important for knowledge of neurosurgical conditions that physicians may encounter. The current status of neurosurgery nonsubinternship clerkships in the United States is unknown; this study determined the availability and format of non-subinternship neurosurgery clerkships in DO (Doctor of Osteopathic Medicine)-granting and MD (Doctor of Medicine)-granting U.S. medical schools. METHODS: Association of American Medical Colleges and American Association of Colleges of Osteopathic Medicine websites were used to obtain contact information for all U.S. medical schools. Respondents were asked whether their school offered a non-subinternship neurosurgery clerkship, if it was required, clerkship length, and whether the clerkship was embedded in another clerkship. Nonsubinternship clerkships/electives/selectives were defined as an exploratory neurosurgery rotation. For nonresponding schools, data were collected from school websites. RESULTS: Data were obtained for 180/199 U.S. medical schools; 142 (79%) provided neurosurgery non-subinternships, including 125/150 (83.3%) MD-granting and 17/30 (57%) DO-granting schools. Four MD-granting schools (2.8%) required the clerkship; 87/142 (61%) offered a stand-alone clerkship, 34/142 (24%) an embedded clerkship, and 21/142 (15%) offered both. In total, 200 clerkships were offered across 142 schools. Most were either >1-2 weeks or >3-4 weeks (69/200, 35% and 89/200, 45%, respectively). CONCLUSIONS: Most U.S. medical schools provide elective neurosurgery non-subinternships. Fewer, although still a majority, of DO-granting schools offer a neurosurgery non-subinternship compared with MD-granting schools.

Virtual Interviews in Neurosurgery Resident Selection: A Follow-up Report.

BACKGROUND: The 2021 U.S. neurosurgery residency match interviews were conducted virtually; we surveyed applicants and interviewers to determine satisfaction with that virtual interview process. Subsequently, we conducted a follow-up survey to determine satisfaction with the virtual interview process after the residency match for faculty interviewers and 2022 interns. METHODS: A 22-question online faculty survey was sent to 116 U.S. neurosurgery training programs. A 26-question survey was sent to these programs for distribution to their intern classes. Data were analyzed quantitatively, including mean Likert score. Open-ended questionnaire responses were reviewed to identify themes. RESULTS: Overall, 32 interns representing 20 programs and 73 faculty representing 62 programs responded. Most respondents agreed that virtual interviews were more convenient (86% faculty, 90% interns) and cost-effective (100% interns) than in-person interviews. Faculty respondents agreed or strongly agreed that virtual interviews were effective to evaluate applicants' competence as residents (44%); fewer faculty agreed or strongly agreed that virtual interviews were an effective way to evaluate candidates' fit in the program (27%). For interns, 44% agreed or strongly agreed that virtual interviews gave them a good sense of the program faculty; 75% agreed or strongly agreed they were satisfied with the process related to where they matched. CONCLUSIONS: Virtual interviews offer an advantage in terms of time and cost but potentially at the expense of adequate faculty assessment of candidates' "fit" within a program's culture. Despite this, interns undergoing an all-virtual interview process report high satisfaction with the results of the residency match.

Perioperative complications and secondary retethering after pediatric tethered cord release surgery.

OBJECTIVE: Tethered cord syndrome refers to a constellation of symptoms characterized by neurological, musculoskeletal, and urinary symptoms, caused by traction on the spinal cord, which can be secondary to various etiologies. Surgical management of simple tethered cord etiologies (e.g., fatty filum) typically consists of a single-level lumbar laminectomy, intradural exploration, and coagulation and sectioning of the filum. More complex etiologies such as lipomyelomeningoceles or scar formation after myelomeningocele repair involve complex dissection and dural reconstruction. The purpose of this study was to evaluate operative complications and long-term outcomes of secondary retethering related to pediatric tethered cord release (TCR) at a tertiary children's hospital. METHODS: Medical records of children who underwent surgery for TCR from July 2014 to March 2023 were retrospectively reviewed. Data collected included demographics, perioperative characteristics, surgical technique, and follow-up duration. Primary outcomes were 60-day postoperative complications and secondary retethering requiring repeat TCR surgery. Univariate and multivariate analyses were performed to identify risk factors associated with complications and secondary retethering. RESULTS: A total of 363 TCR surgeries (146 simple, 217 complex) in 340 patients were identified. The mean follow-up was 442.8 ± 662.2 days for simple TCRs and 733.9 ± 750.3 days for complex TCRs. The adjusted 60-day complication-free survival rate was 96.3% (95% CI 91.3%-98.4%) for simple TCRs and 88.7% (95% CI 82.3%-91.4%) for complex TCRs. Lower weight, shorter surgical times, and intensive care unit admission were associated with complications for simple TCRs. Soft-tissue drains increased complications for complex TCRs. The secondary retethering rates were 1.4% for simple TCRs and 11.9% for complex TCRs. The 1-, 3-, and 5-year progression-free survival rates in complex cases were 94.7% (95% CI 89.1%-97.4%), 77.7% (95% CI 67.3%-85.3%), and 62.6% (95% CI 46.5%-75.1%), respectively. Multivariate analysis revealed that prior detethering (OR 8.15, 95% CI 2.33-28.50; p = 0.001) and use of the operative laser (OR 10.43, 95% CI 1.36-80.26; p = 0.024) were independently associated with secondary retethering in complex cases. CONCLUSIONS: This is the largest series to date examining postoperative complications and long-term secondary retethering in TCR surgery. Simple TCR surgeries demonstrated safety, rare complications, and low secondary retethering rates. Complex TCR surgeries presented higher risks of complications and secondary retethering. Modifiable risk factors such as operative laser use influenced secondary retethering in complex cases.

Incidence and management of dural tears in full-endoscopic unilateral laminotomies for bilateral lumbar decompression.

PURPOSE: To report incidence of dural lacerations in lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) and to describe patient outcomes following a novel full-endoscopic bimanual durotomy repair. METHODS: Retrospective review of prospectively collected database including 5.5 years of single surgeon experience with LE-ULBD. Patients with no durotomy were compared with patients who experienced intraoperative durotomy, including demographics, ASA score, prior surgery, number of levels treated, procedure time, hospital length of stay (LOS), visual analogue scale, perioperative complications, revision surgeries, use of analgesics, and Oswestry Disability Index (ODI). RESULTS: In total, 13/174 patients (7.5%) undergoing LE-ULBD experienced intraoperative durotomy. No significant differences in demographic, clinical or operative variables were identified between the 2 groups. Sustaining a durotomy increased LOS (p = 0.0019); no differences in perioperative complications or rate of revision surgery were identified. There was no difference in minimally clinically important difference for ODI between groups (65.6% for no durotomy versus 55.6% for durotomy, p = 0.54). CONCLUSION: In this cohort, sustaining a durotomy increased LOS but, with accompanying intraoperative repair, did not significantly affect rate of complications, revision surgery or functional outcomes. Our method of bimanual endoscopic dural repair provides an effective approach for repair of dural lacerations in interlaminar ULBD cases.

Single-Electrode Deep Brain Stimulation of Bilateral Posterolateral Globus Pallidus Internus in Patients With Medically Resistant Lesch-Nyhan Syndrome.

Deep brain stimulation (DBS) targeting various locations within the globus pallidus internus (GPi) is emerging as a therapeutic option for patients with medically resistant Lesch-Nyhan syndrome. We report our institutional experience with single-electrode DBS in the bilateral posterolateral GPi as an effective method for reduction of both dystonia and self-injurious behavior. Two pediatric patients aged six and 14 years underwent implantation of bilateral singular DBS leads in the posterolateral GPi and were followed postoperatively through the programming process and symptomatic improvements. Caregivers reported that after DBS in the posterolateral GPi, these patients experienced decreased self-mutilation behavior and decreased dystonia.

A Comparison of Clinical Outcomes for Subependymal Giant Cell Astrocytomas Treated with Laser Interstitial Thermal Therapy, Open Surgical Resection, and mTOR Inhibitors.

INTRODUCTION: Subependymal giant cell astrocytoma (SEGA) is the most common CNS tumor in patients with tuberous sclerosis complex (TSC). Although these are benign, their proximity to the foramen of Monroe frequently causes obstructive hydrocephalus, a potentially fatal complication. Open surgical resection has been the mainstay of treatment; however, this can cause significant morbidity. The development of mTOR inhibitors has changed the treatment landscape, but there are limitations to their use. Laser interstitial thermal therapy (LITT) is an emerging treatment modality that has shown promise in treatment of a variety of intracranial lesions, including SEGAs. We present a single institution, retrospective study of patients treated for SEGAs with LITT, open resection, mTOR inhibitors, or a combination of these modalities. The primary study outcome was tumor volume at most recent follow-up compared with volume at treatment initiation. The secondary outcome was clinical complications associated with treatment modality. METHODS: Retrospective chart review was performed to identify patients with SEGAs treated at our institution from 2010 to 2021. Demographics, treatment information, and complications were collected from the medical record. Tumor volumes were calculated from imaging obtained at initiation of treatment and at most recent follow-up. Kruskal-Wallis nonparametric testing was used to assess differences in tumor volume and follow-up duration between groups. RESULTS: Four patients underwent LITT (3 with LITT only), three underwent open surgical resection, and four were treated with mTOR inhibitors only. Mean percent tumor volume reduction for each group was 48.6 ± 13.8, 90.7 ± 39.8, and 67.1 ± 17.2%, respectively. No statistically significant difference was identified comparing percent tumor volume reduction between the three groups (p = 0.0513). Additionally, there was no statistically significant difference in follow-up duration between groups (p = 0.223). Only 1 patient in our series required permanent CSF diversion and 4 discontinued or decreased the dose of mTOR inhibitor due to either cost or side effects. CONCLUSIONS: Our study suggests that LITT could be considered as a treatment option for SEGAs as it was effective in reducing tumor volume with very few complications. This modality is less invasive than open resection and may be an alternative for patients who are not candidates for mTOR inhibitors. We recommend an updated paradigm for SEGA treatment which includes LITT in select cases after consideration of patient-specific factors.

A Comparative Analysis of Depressive Symptoms Following Sports-Related Concussion in Youth Athletes Versus Their Age-Matched Non-concussed Counterparts.

Background and objective Athletics is the leading cause of pediatric concussion, and depression is a major comorbidity associated with concussion in the pediatric population. Prior studies have described the risk of depression after concussion in high school-, collegiate-, and elite-level athletes, but there is scarce data on younger athletes. Interpretation of existing research on the association of depression with concussions in youth athletes is complicated by diverse study designs, varying measures of depression, differing timelines for symptom development, and a lack of control groups. Furthermore, limited research exists on sex-related differences in the development of depressive symptoms following sports-related concussions (SRC) in younger athletes. This study used the Seattle Pediatric Concussion Research Collaborative (SPCRC) Data Repository to compare depressive symptoms between youth athletes at one month post-SRC and non-concussed age-matched controls by using a standardized measure of depressive symptoms: the Patient Health Questionnaire-9 (PHQ-9). The secondary goal was to compare PHQ-9 scores between males and females for both concussed and non-concussed groups. Methods This study entailed a secondary analysis of data collected as part of the SPCRC Data Repository. We conducted a retrospective subgroup analysis of PHQ-9 scores at one month post-concussion for concussed youth athletes. We compared the PHQ9 scores of concussed youth athletes with PHQ-9 scores collected at the time of enrollment for non-concussed youth athletes. Results After random age-matching, a cohort of 266 patients (133 in the concussed group and 133 in the non-concussed control group) was included in the final analysis. The mean age was 13.8 years (range: 5-18 years). For the concussed group, a history of SRC was associated with a higher mean total PHQ-9 score at one month post-concussion compared with the control group at the time of enrollment (6.14 ±5.46 versus 1.53 ±1.81, respectively, p<0.0001). All nine subdomains of the PHQ-9 showed significantly higher scores in the concussion group compared with the control group (p<0.0001). Significantly higher scores were observed when comparing mean total PHQ-9 scores for male athletes in the concussion group with male athletes in the control group (7.03 ±5.72 versus 1.59 ±1.66, p<0.0001) and for female athletes in the concussion group compared with female controls (5.28 ±5.10 versus 1.49 ±1.92, p<0.0001). No significant differences were observed between sexes for total PHQ-9 scores or PHQ-9 subscores. Conclusion At one month post concussion, youth with SRC demonstrated higher levels of depressive symptoms as measured by PHQ-9 compared with age-matched typically developing controls. No significant differences were identified in total PHQ-9 scores and subscores between male and female participants for either the concussion or control group. This study suggests that clinicians need to be vigilant and monitor for symptoms of depression in young athletes for at least one month post-concussion.

Full Endoscopic Ligamentum Flavum Sparing Unilateral Laminotomy for Bilateral Recess Decompression: Surgical Technique and Clinical Results.

OBJECTIVE: Interlaminar endoscopic spine surgery has been introduced and utilized for lumbar lateral recess decompression. We modified this technique and utilized it for bilateral lateral recess stenoses without significant central stenosis. Here we present the surgical details and clinical outcome of ligamentum flavum sparing unilateral laminotomy for bilateral recess decompression (ULBRD). METHODS: Prospectively collected registry for full-endoscopic surgeries was reviewed retrospectively. One hundred eighty-two consecutive cases from a single center between September 2015 and March 2021 were reviewed and 57 of them whom underwent ULBRD were enrolled for analysis. Basic patient demographic data, perioperative details, surgeryrelated complications, and clinical outcome were reviewed. The detailed surgical technique is presented as well. RESULTS: Among the 57 patients enrolled, 37 were males while the other 20 were females. The mean age was 58.53 ± 14.51 years, and a bimodal age distribution at the age of mid-fifties and mid-sixties or older was noted. The later age-peak was related to coexistence of degenerative scoliosis. The average operative time per lamina was 70.34 ± 20.51 minutes and mean length of stay was 0.56 ± 0.85 days. Four perioperative complications were reported (7.0%) and the overall reoperation rate at the index level within 1 year was 8.8%. The preoperative back/leg visual analogue scale scores and functional outcome scales including EuroQol-5 dimension questionnaire, Oswestry Disability Index presented significant improvement immediately after surgery and were maintained until final follow-up. CONCLUSION: ULBRD for bilateral lateral recess stenoses without significant central stenosis resulted in good clinical outcomes with acceptably low perioperative complications rates. Sufficient decompression was achieved with the central ligamentum flavum being preserved.

Prognostic Value of Hemorrhagic Brainstem Injury on Early Computed Tomography: A TRACK-TBI Study.

BACKGROUND: Traumatic brainstem injury has yet to be incorporated into widely used imaging classification systems for traumatic brain injury (TBI), and questions remain regarding prognostic implications for this TBI subgroup. To address this, retrospective data on patients from the multicenter prospective Transforming Research and Clinical Knowledge in TBI study were studied. METHODS: Patients with brainstem and cerebrum injury (BSI+) were matched by age, sex, and admission Glasgow Coma Scale (GCS) score to patients with cerebrum injuries only. All patients had an interpretable head computed tomography (CT) scan from the first 48 hours after injury and a 6-month Glasgow Outcome Scale Extended (GOSE) score. CT scans were reviewed for brainstem lesions and, when present, characterized by location, size, and type (traumatic axonal injury, contusion, or Duret hemorrhage). Clinical, demographic, and outcome data were then compared between the two groups. RESULTS: Mann-Whitney U-tests showed no significant difference in 6-month GOSE scores in patients with BSI+ (mean 2.7) compared with patients with similar but only cerebrum injuries (mean 3.9), although there is a trend (p = 0.10). However, subclassification by brainstem lesion type, traumatic axonal injury (mean 4.0) versus Duret hemorrhage or contusion (mean 1.4), did identify a proportion of BSI+ with significantly less favorable outcome (p = 0.002). The incorporation of brainstem lesion type (traumatic axonal injury vs. contusion/Duret), along with GCS into a multivariate logistic regression model of favorable outcome (GOSE score 4-8) did show a significant contribution to the prognostication of this brainstem injury subgroup (odds ratio 0.08, 95% confidence interval 0.00-0.67, p = 0.01). CONCLUSIONS: These findings suggest two groups of patients with brainstem injuries may exist with divergent recovery potential after TBI. These data support the notion that newer CT imaging classification systems may augment traditional clinical measures, such as GCS in identifying those patients with TBI and brainstem injuries that stand a higher chance of favorable outcome.

Re-examining decompressive craniectomy medial margin distance from midline as a metric for calculating the risk of post-traumatic hydrocephalus.

Decompressive craniectomy (DC) is a life-saving procedure in severe traumatic brain injury, but is associated with higher rates of post-traumatic hydrocephalus (PTH). The relationship between the medial craniectomy margin's proximity to midline and frequency of developing PTH is controversial. The primary study objective was to determine whether average medial craniectomy margin distance from midline was closer to midline in patients who developed PTH after DC for severe TBI compared to patients that did not. The secondary objective was to determine if a threshold distance from midline could be identified, at which the risk of developing PTH increased if the DC was performed closer to midline than this threshold. A retrospective review was performed of 380 patients undergoing DC at a single institution between March 2004 and November 2014. Clinical, operative and demographic variables were collected, including age, sex, DC parameters and occurrence of PTH. Statistical analysis compared mean axial craniectomy margin distance from midline in patients with versus without PTH. Distances from midline were tested as potential thresholds. No significant difference was identified in mean axial craniectomy margin distance from midline in patients developing PTH compared with patients with no PTH (n = 24, 12.8 mm versus n = 356, 16.6 mm respectively, p = 0.086). No significant cutoff distance from midline was identified (n = 212, p = 0.201). This study, the largest to date, was unable to identify a threshold with sufficient discrimination to support clinical recommendations in terms of DC margins with regard to midline, including thresholds reportedly significant in previously published research.

Early Effects of COVID-19 Pandemic on Neurosurgical Training in the United States: A Case Volume Analysis of 8 Programs.

OBJECTIVE: To determine the impact of the 2019 novel coronavirus disease (COVID-19) pandemic on operative case volume in 8 U.S. neurosurgical residency training programs in early 2020 and to survey these programs regarding training activities during this period. METHODS: A retrospective review was conducted of monthly operative case volumes and types for 8 residency programs for 2019 and January through April 2020. Cases were grouped as elective cranial, elective spine, and nonelective emergent cases. Programs were surveyed regarding residents' perceptions of the impact of COVID-19 on surgical training, didactics, and research participation. Data were analyzed for individual programs and pooled across programs. RESULTS: Across programs, the 2019 monthly mean ± SD case volume was 211 ± 82; 2020 mean ± SD case volumes for January, February, March, and April were 228 ± 93, 214 ± 84, 180 ± 73, and 107 ± 45. Compared with 2019, March and April 2020 mean cases declined 15% (P = 0.003) and 49% (P = 0.002), respectively. COVID-19 affected surgical case volume for all programs; 75% reported didactics negatively affected, and 90% reported COVID-19 resulted in increased research time. Several neurosurgery residents required COVID-19 testing; however, to our knowledge, only 1 resident from the participating programs tested positive. CONCLUSIONS: This study documents a significant reduction in operative volume in 8 neurosurgery residency training programs in early 2020. During this time, neurosurgery residents engaged in online didactics and research-related activities, reporting increased research productivity. Residency programs should collect data to determine the educational impact of the COVID-19 pandemic on residents' operative case volumes, identify deficiencies, and develop plans to mitigate any effects.

Expansile duraplasty and obex exploration compared with bone-only decompression for Chiari malformation type I in children: retrospective review of outcomes and complications.

OBJECTIVE: While a select population of pediatric patients with Chiari malformation type I (CM-I) remain asymptomatic, some patients present with tussive headaches, neurological deficits, progressive scoliosis, and other debilitating symptoms that necessitate surgical intervention. Surgery entails a variety of strategies to restore normal CSF flow, including increasing the posterior fossa volume via bone decompression only, or bone decompression with duraplasty, with or without obex exploration. The indications for duraplasty and obex exploration following bone decompression remain controversial. The objective of this study was to describe an institutional series of pediatric patients undergoing surgery for CM-I, performed by a single neurosurgeon. For patients presenting with a syrinx, the authors compared outcomes following bone-only decompression with duraplasty only and with duraplasty including obex exploration. Clinical outcomes evaluated included resolution of syrinx, scoliosis, presenting symptoms, and surgical complications. METHODS: A retrospective review was conducted of the medical records of 276 consecutive pediatric patients with CM-I operated on at a single institution between 2001 and 2015 by the senior author. Imaging findings of tonsillar descent, associated syrinx (syringomyelia or syringobulbia), basilar invagination, and clinical assessment of CM-I-attributable symptoms and scoliosis were recorded. In patients presenting with a syrinx, clinical outcomes, including syrinx resolution, symptom resolution, and impact on scoliosis progression, were compared for three surgical groups: bone-only/posterior fossa decompression (PFD), PFD with duraplasty (PFDwD), and PFD with duraplasty and obex exploration (PFDwDO). RESULTS: PFD was performed in 25% of patients (69/276), PFDwD in 18% of patients (50/276), and PFDwDO in 57% of patients (157/276). The mean follow-up was 35 ± 35 months. Nearly half of the patients (132/276, 48%) had a syrinx. In patients presenting with a syrinx, PFDwDO was associated with a significantly higher likelihood of syrinx resolution relative to PFD only (HR 2.65, p = 0.028) and a significant difference in time to symptom resolution (HR 2.68, p = 0.033). Scoliosis outcomes did not differ among treatment groups (p = 0.275). Complications were not significantly higher when any duraplasty (PFDwD or PFDwDO) was performed following bone decompression (p > 0.99). CONCLUSIONS: In this series of pediatric patients with CM-I, patients presenting with a syrinx who underwent expansile duraplasty with obex exploration had a significantly greater likelihood of syrinx and symptom resolution, without increased risk of CSF-related complications, compared to those who underwent bone-only decompression.

Teaching the Emergency Neurologic Life Support Course at Two Major Hospitals in Phnom Penh, Cambodia.

OBJECTIVE: To determine the effect of offering a subset of the Emergency Neurological Life Support (ENLS) course modules on provider knowledge and self-reported confidence in acute management of neurocritically ill patients in a low-middle income country (LMIC). METHODS: Eight ENLS modules were provided by in-person lecture using English to Khmer translated slides and a medical translator to physicians and nurses of 2 hospitals in Phnom Penh, Cambodia in May 2019. Providers included emergency, neurology, neurologic surgery, and general intensive care. Demographics, pre- and postcourse knowledge of ENLS content areas, and pre- and postcourse confidence in managing neurocritically ill patients were assessed. Data were pooled across both hospitals for analysis. RESULTS: A total of 57 health care providers were approached for participation: 52 (25 physicians, 27 nurses) participated; 45 completed all study instruments. Pre- and postcourse knowledge scores showed no significant differences between providers. Postcourse, 37/45 (82.2%) participants reported that the content had prepared them for acute management of neurocritically ill patients. Satisfaction with module content ranged from 77.8%-80.0% per module. For the 8 modules, a majority of participants agreed that course material had provided them with knowledge and skills to provide acute care for patients' neurologic emergencies (68.4%-88.6%). CONCLUSIONS: Provision of ENLS course module content increased LMIC provider self-reported knowledge and confidence in acute management of neurocritically ill patients immediately postcourse. Tailoring ENLS course presentation to a particular LMIC setting warrants additional investigation, as does the effect of ENLS course training on neurocritically ill patient outcomes in the LMIC setting.

Evaluating angioarchitectural characteristics of glial and metastatic brain tumors with conventional magnetic resonance imaging.

Primary and metastatic brain tumors can overlap in traditional imaging features detected on preoperative conventional magnetic resonance imaging (MRI). The research objective was to determine whether morphological vascular characteristics present in routine preoperative imaging using traditional MRI sequences are predictive of primary versus metastatic brain tumors; secondarily to determine association of conventional and vascular-related imaging parameters with intraoperative blood loss, pathological invasion, and World Health Organization (WHO) tumor grade. A retrospective review analyzed 100 consecutive intracranial tumor surgeries, 50 WHO grade II-IV gliomas and 50 intracranial metastases. Two blinded expert readers independently evaluated preoperative MRIs, obtained via standard morphological imaging sequences, for adjacent or intra-tumoral arterial aneurysm, peritumoral venous ectasia, prominence, or engorgement ("aberrant peritumoral vessels"), and prominent intra-tumoral flow voids. Multivariate analysis was performed to develop models predictive of glioma and glioblastoma (GBM). Aberrant peritumoral vessels and prominent intra-tumoral flow voids were statistically significant predictors of glioma in univariate analyses (p = 0.048, p = 0.001, respectively) and when combined in multivariate analysis (OR = 5.23, p = 0.001), particularly for GBM (OR = 9.08, p < 0.001). Multivariate modeling identified prominent intra-tumoral flow voids and FLAIR invasion as the strongest combined predictors of gliomas and GBM. Aberrant peritumoral vessels and larger tumor volume predicted higher intraoperative blood loss in all analyses. No vascular-related parameters predicted pathological invasion on multivariate analysis. Aberrant peritumoral vessels and prominent intra-tumoral flow voids were predictive of gliomas, specifically GBM. These vascular characteristics, evaluated on routine clinical preoperative MRI imaging, may aid in distinguishinggliomafrom brainmetastases andmay predict intraoperative blood loss.

Tobacco use, immunosuppressive, chronic pain, and psychiatric conditions are prevalent in women with symptomatic mesh complications undergoing mesh removal surgery.

Purpose: To identify demographic and clinical characteristics of patients with symptomatic pelvic floor mesh complications who underwent mesh removal at our academic medical center. The secondary goal was to determine patient-reported outcomes after mesh removal. Materials and Methods: We conducted a retrospective review of consecutive patients from 2011-2016 undergoing removal of mesh graft for treatment of symptomatic mesh-related complications. Patient demographics, comorbidities, symptoms, and mesh factors were evaluated. Outcomes after explant were determined by the Patient Global Impression of Improvement and a Likert satisfaction scale. Results: One hundred fifty-six symptomatic patients underwent complete or partial pelvic floor mesh removal during the study period. Mid-urethral slings comprised 86% of explanted mesh grafts. Mesh exposure or erosion was identified in 72% of patients. Eighty-one percent of patients presented with pain, and 35% reported pain in the absence of exposure or erosion. Pre-operative comorbidities included psychiatric disease (54.5%), chronic pain (34.0%), irritable bowel syndrome (20.5%) and fibromyalgia (9.6%). Forty-three percent of patients reported current or past tobacco use. At mean follow-up of 14 months, 68% of responding patients reported improvement on the Patient Global Impression of Improvement after surgery. Conclusions: This research identified tobacco use, and psychiatric, immunosuppressive, and chronic pain conditions as prevalent in this cohort of patients undergoing mesh removal. Surgical removal can improve presenting symptoms, including for patients with pain in the absence of other indications.

Anti-PD-L1 antibody direct activation of macrophages contributes to a radiation-induced abscopal response in glioblastoma.

BACKGROUND: Most glioblastomas recur near prior radiation treatment sites. Future clinical success will require achieving and optimizing an "abscopal effect," whereby unirradiated neoplastic cells outside treatment sites are recognized and attacked by the immune system. Radiation combined with anti-programmed cell death ligand 1 (PD-L1) demonstrated modest efficacy in phase II human glioblastoma clinical trials, but the mechanism and relevance of the abscopal effect during this response remain unknown. METHODS: We modified an immune-competent, genetically driven mouse glioma model (forced platelet derived growth factor [PDGF] expression + phosphatase and tensin homolog loss) where a portion of the tumor burden is irradiated (PDGF) and another unirradiated luciferase-expressing tumor (PDGF + luciferase) is used as a readout of the abscopal effect following systemic anti-PD-L1 immunotherapy. We assessed relevance of tumor neoepitope during the abscopal response by inducing expression of epidermal growth factor receptor variant III (EGFRvIII) (PDGF + EGFRvIII). Statistical tests were two-sided. RESULTS: Following radiation of one lesion, anti-PD-L1 immunotherapy enhanced the abscopal response to the unirradiated lesion. In PDGF-driven gliomas without tumor neoepitope (PDGF + luciferase, n = 8), the abscopal response occurred via anti-PD-L1 driven, extracellular signal-regulated kinase-mediated, bone marrow-derived macrophage phagocytosis of adjacent unirradiated tumor cells, with modest survival implications (median survival 41 days vs radiation alone 37.5 days, P = 0.03). In PDGF-driven gliomas with tumor neoepitope (PDGF + EGFRvIII, n = 8), anti-PD-L1 enhanced abscopal response was associated with macrophage and T-cell infiltration and increased survival benefit (median survival 36 days vs radiation alone 28 days, P = 0.001). CONCLUSION: Our results indicate that anti-PD-L1 immunotherapy enhances a radiation- induced abscopal response via canonical T-cell activation and direct macrophage activation in glioblastoma.