How modern treatments have modified the role of surgery in pediatric low-grade glioma.

Low-grade gliomas are the most common brain tumor of childhood, and complete resection offers a high likelihood of cure. However, in many instances, tumors may not be surgically accessible without substantial morbidity, particularly in regard to gliomas arising from the optic or hypothalamic regions, as well as the brainstem. When gross total resection is not feasible, alternative treatment strategies must be considered. While conventional chemotherapy and radiation therapy have long been the backbone of adjuvant therapy for low-grade glioma, emerging techniques and technologies are rapidly changing the landscape of care for patients with this disease. This article seeks to review the current and emerging modalities of treatment for pediatric low-grade glioma.

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.

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.

Review and update on pediatric ependymoma.

Since our last Special Annual Issue dedicated to the topic of ependymoma in 2009, critical advancements have been made in the understanding of this disease which is largely confined to childhood. In the era of molecular profiling, the prior classification of ependymoma based on histology has become largely irrelevant, with multiple new subtypes of this disease now being described in the newest 2021 WHO CNS Tumor Classification System. Despite our advancements in understanding the underlying biology of these tumors, the mainstays of treatment-gross total surgical resection followed by confocal radiation therapy-have continued to yield the best treatment results across multiple studies and centers. Here, we provide an update on our understanding of the advancements made in tumor biology, surgical, and oncologic management of this disease. As we move into an era of more personalized medicine, it is critical to reflect on our historical understanding of different disease entities, to better understand the future directions of our treatments.

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.

Fixed, Dilated, and Conversing-Unreactive Pupil With Preserved Consciousness Indicating Acutely Rising Intracranial Pressure due to Traumatic Intraparenchymal Contusions: Case Report and Review of the Literature.

Patients with fixed and dilated pupils (FDPs) due to rising intracranial pressure (ICP) typically experience a deterioration in consciousness. We describe an exceptional case of a patient with bifrontal contusions who developed worsening edema and a unilaterally FDP while maintaining consciousness and the ability to communicate. A 58-year-old man with history of hypertension and diabetes mellitus type II presented after being assaulted, with bifrontal contusions and right frontal intraparenchymal hemorrhage. On hospital day 8, his right pupil became fixed (NPi 0) and dilated (4.8 mm). The patient was drowsy, arousable to tactile stimuli, answering questions, oriented to place and time, following commands on his right side, maintaining Glasgow Coma Scale of 14 (E4, V5, M6). He described complete loss of vision and could not identify objects or count fingers. His gaze was dysconjugate with impaired vertical excursion and inability to fully abduct to the right side. Corneal reflexes were intact bilaterally. Hypertonic saline and mannitol produced no improvement in his pupillary exam. Head computed tomography showed worsening midline shift and interval increase in subfalcine herniation related to increased peri-hematoma edema. We performed an emergent right-sided decompressive hemicraniectomy with durotomy and duraplasty. His pupil became reactive 5 hours after surgery. While FDP without deterioration of consciousness has been described due to traumatic subdural and epidural hematomas, we report this unusual constellation as a sign of rising ICP and impeding herniation due to intraparenchymal contusions, highlighting that any pupillary change warrants prompt work-up and intervention.

Robot-assisted stereoelectroencephalography in young children: technical challenges and considerations.

Robot-assisted stereoelectroencephalography (sEEG) is frequently employed to localize epileptogenic zones in patients with medically refractory epilepsy (MRE). Its methodology is well described in adults, but less so in children. Given the limited information available on pediatric applications, the objective is to describe the unique technical challenges and considerations of sEEG in the pediatric population. In this report, we describe our institutional experience with the technical aspects of robot-assisted sEEG in an exclusively pediatric epilepsy surgery unit, focusing on pre-, intra-, and post-operative nuances that are particular to the pediatric population. The pediatric population presents several unique challenges in sEEG, including reduced skull thickness relative to adults, incomplete neurologic development, and often special behavioral considerations. Pre-operative selection of putative epileptogenic zones requires careful multidisciplinary decision-making. Intraoperative attention to nuances in positioning, clamp selection, registration, and electrode placement are necessary. Activity considerations and electrode migration and removal are key post-operative considerations. Robot-assisted sEEG is a valuable tool in the armamentarium of techniques to characterize MRE. However, special considerations must be given to the pediatric population to optimize safety and efficacy.

Endoscopic Spine Surgery in Athletes: Case Series and Review of Literature.

BACKGROUND: Degenerative spine disease is common in athletes and can progress to requiring surgical intervention. Traditional open surgical techniques necessitate prolonged recovery time and time away from play. Newly developed endoscopic surgical techniques may promote faster healing and recovery, and increased return to play. The goal of this paper is to summarize the current evidence in return to play after spine surgery and to present our series of 3 athletes who underwent endoscopic spine surgery. METHODS: A complete search of all PubMed indexed articles pertaining to spine surgery in athletes was conducted. This was supplemented by a 3-patient case series of our own endoscopic spine experience in athletes. RESULTS: There are no current widely accepted guidelines for return to play after spinal surgery. The best evidence available cites a return to play of 81% at 5.2-8.7 months after traditional open and minimally invasive surgery, and endoscopic surgery produces an average 88% return to play rate at 3 months. CONCLUSIONS: Although return to play can vary widely, case-based evidence as well as biomechanical principles support endoscopic spine surgery as a viable surgical modality for the treatment of spinal pathologies in athletes.

Resection of a recurrent pineal region teratoma via a posterior interhemispheric transcallosal approach.

The authors describe the unusual case of a 6-year-old boy presenting with decorticate posturing, diminished hearing, and an inability to open his eyes, despite being verbally responsive. He underwent a posterior interhemispheric transcallosal intervenous approach for resection of a pineal region mature teratoma, which recurred 2 years postoperatively. This video demonstrates his initial surgery and reresection, illustrating the value of this approach for more complex lesions that involve the internal cerebral veins (ICVs). At the time of recurrence, microsurgical dissection of the scarred interhemispheric fissure was required to facilitate removal of the multifocal recurrent teratoma, resulting in gross-total resection. The video can be found here: https://stream.cadmore.media/r10.3171/2021.4.FOCVID2134.

Pediatric abusive head trauma and stroke.

OBJECTIVE Despite established risk factors, abusive head trauma (AHT) continues to plague our communities. Cerebrovascular accident (CVA), depicted as areas of hypodensity on CT scans or diffusion restriction on MR images, is a well-known consequence of AHT, but its etiology remains elusive. The authors hypothesize that a CVA, in isolation or in conjunction with other intracranial injuries, compounds the severity of a child's injury, which in turn leads to greater health care utilization, including surgical services, and an increased risk of death. METHODS The authors conducted a retrospective observational study to evaluate data obtained in all children with AHT who presented to Le Bonheur Children's Hospital (LBCH) from January 2009 through August 2016. Demographic, hospital course, radiological, cost, and readmission information was collected. Children with one or more CVA were compared with those without a CVA. RESULTS The authors identified 282 children with AHT, of whom 79 (28%) had one or more CVA. Compared with individuals without a CVA, children with a stroke were of similar overall age (6 months), sex (61% male), and race (56% African-American) and had similar insurance status (81% public). Just under half of all children with a stroke (38/79, 48%) were between 1-6 months of age. Thirty-five stroke patients (44%) had a Grade II injury, and 44 (56%) had a Grade III injury. The majority of stroke cases were bilateral (78%), multifocal (85%), associated with an overlying subdural hematoma (86%), and were watershed/hypoperfusion in morphology (73%). Thirty-six children (46%) had a hemispheric stroke. There were a total of 48 neurosurgical procedures performed on 28 stroke patients. Overall median hospital length of stay (11 vs 3 days), total hospital charges ($13.8 vs $6.6 million), and mean charges per patient ($174,700 vs $32,500) were significantly higher in the stroke cohort as a whole, as well as by injury grade (II and III). Twenty children in the stroke cohort (25%) died as a direct result of their AHT, whereas only 2 children in the nonstroke cohort died (1%). There was a 30% readmission rate within the first 180-day postinjury period for patients in the stroke cohort, and of these, approximately 50% required additional neurosurgical intervention(s). CONCLUSIONS One or more strokes in a child with AHT indicate a particularly severe injury. These children have longer hospital stays, greater hospital charges, and a greater likelihood of needing a neurosurgical intervention (i.e., bedside procedure or surgery). Stroke is such an important predictor of health care utilization and outcome that it warrants a subcategory for both Grade II and Grade III injuries. It should be noted that the word "stroke" or "CVA" should not automatically imply arterial compromise in this population.

Abusive head trauma: an epidemiological and cost analysis.

OBJECTIVE Research on pediatric abusive head trauma (AHT) has largely focused on clinical presentation and management. The authors sought to review a single-institution experience from a public health perspective to gain a better understanding of the local population affected, determine overall incidence and seasonal trends, and provide details on the initial hospitalization, including extent of injuries, neurosurgical interventions, and hospital charges. METHODS All cases of AHT involving patients who presented to Le Bonheur Children's Hospital (LBCH) from 2009 through 2014 were identified. AHT was defined as skull fracture or intracranial hemorrhage in a child under the age of 5 years with a suspicious mechanism or evidence of other intentional injuries, such as retinal hemorrhages, old or new fractures, or soft-tissue bruising. Injuries were categorized as Grade I (skull fracture only), Grade II (intracranial hemorrhage or edema not requiring surgical intervention), or Grade III (intracranial hemorrhage requiring intervention or death due to brain injury). RESULTS Two hundred thirteen AHT cases were identified. The demographics of the study population are similar to those reported in the literature: the majority of the patients involved were 6 months of age or younger (55%), male (61%), African American (47%), and publicly insured (82%). One hundred one neurosurgical procedures were performed in 58 children, with the most common being bur hole placement for treatment of subdural collections (25%) and decompressive hemicraniectomy (22%). The annual incidence rate rose from 2009 (19.6 cases per 100,000 in the population under 5 years of age) to 2014 (47.4 cases per 100,000) and showed seasonal peaks in January, July, and October (6-year average single-month incidence, respectively, 24.7, 21.7, and 24.7 per 100,000). The total hospital charges were $13,014,584, with a median cost of $27,939. Treatment costs for children who required surgical intervention (i.e., those with Grade III) were up to 10 times those of children with less severe injuries. CONCLUSIONS In the authors' local population, victims of AHT are overwhelmingly infants, are more often male than female, and are disproportionately from lower socioeconomic ranks. The incidence is increasing and initial hospitalization charges are substantial and variable. The authors introduce a simple 3-tiered injury classification scheme that adequately stratifies length of hospital stay and cost.

Medulloblastoma Genotype Dictates Blood Brain Barrier Phenotype.

The childhood brain tumor, medulloblastoma, includes four subtypes with very different prognoses. Here, we show that paracrine signals driven by mutant ß-catenin in WNT-medulloblastoma, an essentially curable form of the disease, induce an aberrant fenestrated vasculature that permits the accumulation of high levels of intra-tumoral chemotherapy and a robust therapeutic response. In contrast, SHH-medulloblastoma, a less curable disease subtype, contains an intact blood brain barrier, rendering this tumor impermeable and resistant to chemotherapy. The medulloblastoma-endothelial cell paracrine axis can be manipulated in vivo, altering chemotherapy permeability and clinical response. Thus, medulloblastoma genotype dictates tumor vessel phenotype, explaining in part the disparate prognoses among medulloblastoma subtypes and suggesting an approach to enhance the chemoresponsiveness of other brain tumors.