Pediatric glioma immune profiling identifies TIM3 as a therapeutic target in BRAF fusion pilocytic astrocytoma.

Despite being the leading cause of cancer-related childhood mortality, pediatric gliomas have been relatively understudied, and the repurposing of immunotherapies has not been successful. Whole-transcriptome sequencing, single-cell sequencing, and sequential multiplex immunofluorescence were used to identify an immunotherapeutic strategy that could be applied to multiple preclinical glioma models. MAPK-driven pediatric gliomas have a higher IFN signature relative to other molecular subgroups. Single-cell sequencing identified an activated and cytotoxic microglia (MG) population designated MG-Act in BRAF-fused, MAPK-activated pilocytic astrocytoma (PA), but not in high-grade gliomas or normal brain. T cell immunoglobulin and mucin domain 3 (TIM3) was expressed on MG-Act and on the myeloid cells lining the tumor vasculature but not normal brain vasculature. TIM3 expression became upregulated on immune cells in the PA microenvironment, and anti-TIM3 reprogrammed ex vivo immune cells from human PAs to a proinflammatory cytotoxic phenotype. In a genetically engineered murine model of MAPK-driven, low-grade gliomas, anti-TIM3 treatment increased median survival over IgG- and anti-PD-1-treated mice. Single-cell RNA-Seq data during the therapeutic window of anti-TIM3 revealed enrichment of the MG-Act population. The therapeutic activity of anti-TIM3 was abrogated in mice on the CX3CR1 MG-KO background. These data support the use of anti-TIM3 in clinical trials of pediatric low-grade, MAPK-driven gliomas.

Re-examining the classification of abdominal pseudocysts as surgical site infections through review of broad-range polymerase chain reaction results.

BACKGROUND: The Hydrocephalus Clinical Research Network-quality group (HCRNq) historically defined all abdominal pseudocysts associated with a ventriculoperitoneal shunt as a surgical site infection regardless of culture result. METHODS: We retrospectively reviewed broad-range polymerase chain reaction (BRPCR) results sent between January 2017 and July 2023 from abdominal pseudocyst fluid sent from hospitals around the country to a reference laboratory to help further characterize these collections. RESULTS: A total of 19 samples were tested via BRPCR between 1/2017 and 7/2023. Two (10.5 %) had organisms identified; one with Staphylococcus epidermidis and one with Candida parapsilosis. No fastidious organisms that would be expected to not grow with typical culture techniques were identified. CONCLUSIONS: Few abdominal pseudocysts had organisms identified by BRPCR, suggesting that not all pseudocysts are due to infectious causes. Consideration should be given to alternate causes of pseudocyst development when cultures are negative.

Experience in endoscope choice for neuroendoscopic lavage for intraventricular hemorrhage of prematurity: a systematic review.

OBJECTIVE: Intraventricular hemorrhage (IVH) of prematurity occurs in 20-38% of infants born < 28 weeks gestational age and 15% of infants born in 28-32 weeks gestational age. Treatment has evolved from conservative management and CSF diversion of temporizing and shunting procedures to include strategies aimed at primarily clearing intraventricular blood products. Neuroendoscopic lavage (NEL) aims to decrease the intraventricular blood burden under the same anesthetic as temporizing CSF diversion measures in cases of hydrocephalus from IVH of prematurity. Given the variety of neuroendoscopes, we sought to review the literature and practical considerations to help guide neuroendoscope selection when planning NEL. METHODS: We conducted a systematic review of the literature on neuroendoscopic lavage in IVH of prematurity to examine data on the choice of neuroendoscope and outcomes regarding shunt rate. We then collected manufacturer data on neuroendoscopic devices, including inflow and outflow mechanisms, working channel specifications, and tools compatible with the working channel. We paired this information with the advantages and disadvantages reported in the literature and observations from the experiences of pediatric neurosurgeons from several institutions to provide a pragmatic evaluation of international clinical experience with each neuroendoscope in NEL. RESULTS: Eight studies were identified; four neuroendoscopes have been used for NEL as reported in the literature. These include the Karl Storz Flexible Neuroendoscope, LOTTA® system, GAAB system, and Aesculap MINOP® system. The LOTTA® and MINOP® systems were similar in setup and instrument options. Positive neuroendoscope features for NEL include increased degrees of visualization, better visualization with the evolution of light and camera sources, the ability to sterilize with autoclave processes, balanced inflow and outflow mechanisms via separate channels, and a working channel. Neuroendoscope disadvantages for NEL may include special sterilization requirements, large outer diameter, and limitations in working channels. CONCLUSIONS: A neuroendoscope integrating continuous irrigation, characterized by measured inflow and outflow via separate channels and multiple associated instruments, appears to be the most commonly used technology in the literature. As neuroendoscopes evolve, maximizing clear visualization, adequate inflow, measured outflow, and large enough working channels for paired instrumentation while minimizing the footprint of the outer diameter will be most advantageous when applied for NEL in premature infants.

Examining barriers to care: a retrospective cohort analysis investigating the relationship between hospital volume and outcomes in pediatric patients with cerebral arteriovenous malformations.

OBJECTIVE: Comprehensive data on treatment patterns of pediatric cerebral arteriovenous malformations (AVMs) are lacking. The authors' aim was to examine national trends, assess the effect of hospital volume on outcomes, and identify variables associated with treatment at high-volume centers. METHODS: Pediatric AVM admissions (for ruptured and unruptured lesions) occurring in the US in 2016 and 2019 were identified using the Kids' Inpatient Database. Demographics, treatment methods, costs, and outcomes were recorded. The effect of hospital AVM volume on outcomes and factors associated with treatment at higher-volume hospitals were analyzed. RESULTS: Among 2752 AVM admissions identified, 730 (26.5%) patients underwent craniotomy, endovascular treatment, or a combination. High-volume (vs low-volume) centers saw lower proportions of Black (8.7% vs 12.9%, p < 0.001) and lowest-income quartile (20.7% vs 27.9%, p < 0.001) patients, but were more likely to provide endovascular intervention (19.5%) than low-volume institutions (13.7%) (p = 0.001). Patients treated at high-volume hospitals had insignificantly lower numbers of complications (mean 2.66 vs 4.17, p = 0.105) but significantly lower odds of nonroutine discharge (OR 0.18 [95% CI 0.06-0.53], p = 0.009) and death (OR 0.13 [95% CI 0.02-0.75], p = 0.023). Admissions at high-volume hospitals cost more than at low-volume hospitals, regardless of whether intervention was performed ($64,811 vs $48,677, p = 0.001) or not ($64,137 vs $33,779, p < 0.001). Multivariable analysis demonstrated that Hispanic children, patients who received AVM treatment, and those in higher-income quartiles had higher odds of treatment at high-volume hospitals. CONCLUSIONS: In this largest study of US pediatric cerebral AVM admissions to date, higher hospital volume correlated with several better outcomes, particularly when patients underwent intervention. Multivariable analysis demonstrated that higher income and Hispanic race were associated with treatment at high-volume centers, where endovascular care is more common. The findings highlight the fact that ensuring access to appropriate treatment of patients of all races and socioeconomic classes must be a focus.

A Well-Being Well-Check for Neurosurgery: Evidence-Based Suggestions for Our Specialty Based on a Systematic Review.

BACKGROUND: The path through neurosurgery is rigorous. Many neurosurgeons may experience burnout, depression, or suicide throughout training and practice. We review the literature to help foster a culture of awareness and self-care and arm trainees with coping skills to reduce burnout and, thus, suicidality during all phases of their medical careers. METHODS: A systematic search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using 4 databases. 7 studies were included. RESULTS: Overlying themes of interventions were to increase balance, mindfulness, and physical fitness. The most common interventions included in programs were educational and physical activity. We suggest a comprehensive wellness program emphasizing interventions from 4 wellness dimensions-physical, spiritual, mental, and emotional. CONCLUSIONS: Many neurosurgeons experience burnout, leading to a lack of satisfaction and early retirement; this necessitates a discipline-wide acknowledgment of endemic burnout among neurosurgeons. Systemic changes are needed to refine the training process and prioritize physician well-being- this cannot be left to chance.

Neurosurgery trainee well-being in a pediatric neurosurgery hospital: baseline data to motivate toward implementing change.

OBJECTIVE: The aim of this study was to obtain aggregated baseline pediatric neurosurgery well-being data at a tertiary care institution. METHODS: An institutional grant funded the completion of the Maslach Burnout Inventory (MBI) by 100% (n = 13) of the trainees during a 1-year period, including 1 pediatric neurosurgery fellow and 12 residents from 4 regional neurosurgery training programs. Aggregated and anonymized group results included frequency scores ranging from 0 (never) to 6 (every day). The mean ± SD group scores were compared to the general population of > 11,000 people in the human services professions. Burnout profiles were calculated on the basis of MBI scale scores by using established comparisons to standardized normal values. Burnout profile types include engaged, ineffective, overextended, disengaged, and burnout. RESULTS: The mean ± SD score for emotional exhaustion was 2.6 ± 1.1 for trainees compared with 2.3 ± 1.2 in the comparison population. The mean ± SD score for depersonalization was 1.6 ± 1 compared with 1.7 ± 1.2 in the comparison population. The mean ± SD score for personal accomplishment was 4.9 ± 0.7 compared with 4.3 ± 0.9 in the comparison population. Profiles were classified as engaged (n = 6), ineffective (n = 3), overextended (n = 3), and burnout (n = 1). CONCLUSIONS: Problematic profiles were present for more than half (7 [53.8%]) of pediatric neurosurgery trainees who cited higher emotional exhaustion than the general population of healthcare providers. Trainees scored lower in depersonalization and higher in personal accomplishment compared with the general population, which are both protective against burnout. Targeting factors that contribute to emotional exhaustion may have an impact on improving the overall well-being of pediatric neurosurgery trainees.

Machine learning models for predicting seizure outcome after MR-guided laser interstitial thermal therapy in children.

OBJECTIVE: MR-guided laser interstitial thermal therapy (MRgLITT) is associated with lower seizure-free outcome but better safety profile compared to open surgery. However, the predictors of seizure freedom following MRgLITT remain uncertain. This study aimed to use machine learning to predict seizure-free outcome following MRgLITT and to identify important predictors of seizure freedom in children with drug-resistant epilepsy. METHODS: This multicenter study included children treated with MRgLITT for drug-resistant epilepsy at 13 epilepsy centers. The authors used clinical data, diagnostic investigations, and ablation features to predict seizure-free outcome at 1 year post-MRgLITT. Patients from 12 centers formed the training cohort, and patients in the remaining center formed the testing cohort. Five machine learning algorithms were developed on the training data by using 10-fold cross-validation, and model performance was measured on the testing cohort. The models were developed and tested on the complete feature set. Subsequently, 3 feature selection methods were used to identify important predictors. The authors then assessed performance of the parsimonious models based on these important variables. RESULTS: This study included 268 patients who underwent MRgLITT, of whom 44.4% had achieved seizure freedom at 1 year post-MRgLITT. A gradient-boosting machine algorithm using the complete feature set yielded the highest area under the curve (AUC) on the testing set (AUC 0.67 [95% CI 0.50-0.82], sensitivity 0.71 [95% CI 0.47-0.88], and specificity 0.66 [95% CI 0.50-0.81]). Logistic regression, random forest, support vector machine, and neural network yielded lower AUCs (0.58-0.63) compared to the gradient-boosting machine but the findings were not statistically significant (all p > 0.05). The 3 feature selection methods identified video-EEG concordance, lesion size, preoperative seizure frequency, and number of antiseizure medications as good prognostic features for predicting seizure freedom. The parsimonious models based on important features identified by univariate feature selection slightly improved model performance compared to the complete feature set. CONCLUSIONS: Understanding the predictors of seizure freedom after MRgLITT will assist with prognostication.

Axenfeld-Rieger syndrome: A systematic review examining genetic, neurological, and neurovascular associations to inform screening.

Axenfeld-Rieger Syndrome (ARS) is comprised of a group of autosomal dominant disorders that are each characterized by anterior segment abnormalities of the eye. Mutations in the transcription factors FOXC1 or PITX2 are the most well-studied genetic manifestations of this syndrome. Due to the rarity this syndrome, ARS-associated neurological manifestations have not been well characterized. The purpose of this systematic review is to characterize and describe ARS neurologic manifestations that affect the cerebral vasculature and their early and late sequelae. PRISMA guidelines were followed; studies meeting inclusion criteria were analyzed for study design, evidence level, number of patients, patient age, whether the patients were related, genotype, ocular findings, and nervous system findings, specifically neurostructural and neurovascular manifestations. 63 studies met inclusion criteria, 60 (95%) were case studies or case series. The FOXC1 gene was most commonly found, followed by COL4A1, then PITX2. The most commonly described structural neurological findings were white matter abnormalities in 26 (41.3%) of studies, followed by Dandy-Walker Complex 12 (19%), and agenesis of the corpus callosum 11 (17%). Neurovascular findings were examined in 6 (9%) of studies, identifying stroke, cerebral small vessel disease (CSVD), tortuosity/dolichoectasia of arteries, among others, with no mention of moyamoya. This is the first systematic review investigating the genetic, neurological, and neurovascular associations with ARS. Structural neurological manifestations were common, yet often benign, perhaps limiting the utility of MRI screening. Neurovascular abnormalities, specifically stroke and CSVD, were identified in this population. Stroke risk was present in the presence and absence of cardiac comorbidities. These findings suggest a relationship between ARS and neurovascular findings; however, larger scale studies are necessary inform therapeutic decisions.

Rett Syndrome-Associated Scoliosis: Analysis of National Trends and Treatment Patterns of a Rare Indication for Posterior Instrumented Fusion.

STUDY DESIGN: Retrospective database cohort study. OBJECTIVE: To evaluate U.S. treatment trends and inpatient outcomes for children undergoing posterior spinal fusion (PSF) for Rett syndrome (RTT)-associated scoliosis (RAS). SUMMARY OF BACKGROUND DATA: RTT is a rare, sporadic neurodevelopmental disorder presenting in childhood with developmental regression, ataxia, and seizures. RAS occurs in 50% to 80% of cases of RTT, but little is known about the case volume and perioperative experience for children undergoing PSF. MATERIALS AND METHODS: Using the International Classification of Diseases Ninth and 10th revision codes in the national Kids' Inpatient Database, we identified children with RTT who underwent PSF from 2000 to 2019. Annual case volumes were analyzed. Clinical characteristics and outcomes were compared with those of a cohort of patients with neuromuscular scoliosis (NMS). RESULTS: Among 220 patients with RAS, 216 (98.2%) were females (mean age at surgery: 12.3±3.3 yr). Surgical case incidence steadily increased over 19 years, with more RAS admissions in the South (31.4%). Overall, patients with RAS demonstrated a higher mean Elixhauser Comorbidity Index score (2 vs . 1, P < 0.001) and had more perioperative complications (41.4% vs . 18%, P < 0.001) than patients with NMS. RTT diagnosis independently predicted higher odds of any complications (odds ratio: 1.98, P < 0.001) and increased length of stay (odds ratio: 1.18, P = 0.009) for admissions for PSF. CONCLUSIONS: Surgical treatment for RAS is rare but increased over a 19-year period. Cases appear to be clustering by region, with the highest proportion in the South. The higher Elixhauser Comorbidity Index in RAS patients predicted higher costs, longer hospital stays, more complications (particularly respiratory), and more nonroutine discharge disposition than in other patients with NMS. RTT was independently associated with higher odds of complications and longer length of stay. Because RAS cases appear to be increasing in number, future studies should emphasize methods to reduce morbidity and investigate deformity-specific metrics to help better understand this population.

Gaps in transitional care to adulthood for patients with cerebral palsy: a systematic review.

PURPOSE: The transition from pediatric to adult care can be complex and difficult to navigate for adolescents with cerebral palsy (CP). We aimed to assess the current state of transitional care for young persons with CP and delineate guidelines for best practice with opportunities for intervention. METHODS: A systematic review was conducted using PRISMA guidelines to search PubMed, Embase, and Scopus databases. Articles were screened for relevance via title and abstract prior to full-text review. RESULTS: Of 3151 resultant articles, 27 observational studies were included. Fourteen (52%) studies assessed clinical outcomes of patients with CP during and post-transition. Transition-associated poor outcomes included housing instability, unemployment, difficulty forming relationships, increased hospital admission rates, and decreased use of rehabilitation services. Factors associated with improved outcomes included family participation, promotion of self-efficacy, and meeting the adult team before transition. Nine (33%) studies conducted interviews with transition-age persons with CP. Key themes were a lack of transition preparedness, difficulty navigating the adult system, gaps in seamless care, and limited accessibility to specialists and environments suitable for patients with complex care needs. Four (15%) studies examined features of current transition services. Perceived barriers included poor communication within health service teams, limited adult providers accepting CP patients, and the lack of financial resources for specialized care. There was no standardized transition tool or approach. CONCLUSION: These findings underscore the importance of a planned transition process in optimizing long-term medical and psychosocial outcomes for persons with CP. Further research, including translational, team-based, and community-engaged research, are needed.

Your Brain on Reddit: Exploring Neurosurgical Concerns on a Popular Social Media Site.

OBJECTIVE: Social media has irreversibly impacted global interpersonal connectivity. This study aims to understand how information discussed in condition-specific communities, called "subreddits," on the major social media platform Reddit, can improve education by medical providers. METHODS: The top 50 Reddit posts in each subreddit's "hot" tab were retroactively screened from June 1, 2022. Posts written by those 18 and older who had the condition or were engaging in a better understanding of the condition were included in the analysis. In addition, posts were placed in 1 of 6 categories based on the redditors' primary questions: social advice, health advice, providing health education or suggesting equipment, personal experience/progress, researchers recruiting patients for research, or others. RESULTS: We identified 605 posts within 15 subreddits related to cranial neurosurgical topics including epilepsy, traumatic brain injury, stroke, brain tumors/cancer, seizures, hydrocephalus, cerebrospinal fluid leaks, Chiari malformations, aneurysms, pineal cysts, ataxia, and moyamoya. Asking for health advice was the most common form of information seeking across subreddits (53.6%), specifically treatment-related questions (41.0%). Redditors from r/epilepsy and r/seizures constituted 84.6% of nonsurgical treatment questions relating to antiepileptic dosing or side effects. CONCLUSIONS: Cranial neurosurgical disease can overwhelm patients, leaving them with unaddressed questions. Reddit provides anonymity and camaraderie within condition-specific communities not found at the doctor's office. The ease of access to an Internet community may encourage redditors to seek health information online.

Comparison of long-term survival with continued medical therapy, vagus nerve stimulation, and cranial epilepsy surgery in paediatric patients with drug-resistant epilepsy in the USA: an observational cohort study.

BACKGROUND: Long-term survival in paediatric epilepsy is incompletely characterised. A better understanding of treatment effects on mortality in paediatric patients with drug-resistant epilepsy is needed for health-care decision making. We aimed to compare the long-term survival rates associated with antiseizure medications only, antiseizure medications plus vagus nerve stimulation (VNS), and antiseizure medications plus cranial epilepsy surgery in paediatric patients with drug-resistant epilepsy using a large national administrative database in the USA. METHODS: In this observational cohort study, patients aged 0-17 years who were diagnosed with drug-resistant epilepsy using International Classificiaton of Diseases codes between Jan 1, 2004, and Dec 31, 2020, were identified from the Pediatric Health Information System, an administrative database that contains inpatient, emergency department, ambulatory, and observation unit encounter-level data from more than 49 children's hospitals in the USA. Patients treated with at least three types of antiseizure medications were included in the medical therapy cohort, those treated with antiseizure medications plus VNS were included in the VNS cohort, and those treated with antiseizure medications plus cranial epilepsy surgery were included in the surgery cohort. Participants were followed up until the date of their last clinical encounter, in-hospital death, or Dec 31, 2020. Inverse probability of treatment weighting (IPTW) was used to balance baseline demographics and clinical characteristics between treatment groups. The unconditional probabilities of survival were estimated by weighted Kaplan-Meier analysis. A weighted Cox proportional hazards model was used to investigate the association between risk of overall death and age, sex, geographical region, race and ethnicity, comorbidity, primary diagnosis, insurance, and treatment. FINDINGS: This study included 10 240 patients treated with antiseizure medications only, 5019 patients treated with antiseizure medications plus VNS, and 3033 patients treated with antiseizure medications plus cranial epilepsy surgery. The median age of paediatric patients was 7 years (IQR 4-12) in the medical therapy cohort, 9 years (6-13) in the VNS cohort, and 9 years (5-13) in the surgery cohort. The IPTW-adjusted probabilities of surviving beyond 10 years were 89·27% (95% CI 87·71-90·85) for the medical therapy cohort, 92·65% (90·62-94·72) for the VNS cohort, and 98·45% (97·53-99·38) for the surgery cohort. The difference in survival probabilities was significant (log-rank p<0·0001). Compared with the medical therapy cohort, the IPTW-adjusted hazard ratio for overall death was 0·60 (95% CI 0·50-0·74) for the VNS cohort and 0·19 (0·10-0·33) for the surgery cohort. INTERPRETATION: Paediatric patients with drug-resistant epilepsy who underwent cranial epilepsy surgery or VNS had a higher survival rate than those who received only medical treatment. These findings highlight the importance of a multidisciplinary comprehensive team approach to the treatment of epilepsy, which includes tailored evaluation and deployment of medical and surgical treatment options for patients with this challenging disease. FUNDING: None.

Challenges in defining surgical-site infections following hydrocephalus surgeries.

Multiple organizations track neurosurgical surgical-site infection (SSI) rates, but significant variation exists among reporting criteria. We report our center's experience with the variation in cases captured by 2 major definitions. Standardization could support improvement activities and SSI reduction.

Disability or Death: A Focused Review of Informed Consent in Pediatric Neurosurgery.

The management of pediatric neurosurgical disease often requires families to choose between long-term disability and premature death. This decision-making is codified by informed consent. In practice, decision-making is heavily weighted toward intervening to prevent death, often with less consideration of the realities of long-term disability. We analyze long-term disability in pediatric neurosurgical disease from the perspectives of patients, families, and society. We then present a pragmatic framework and conversational approach for addressing informed consent discussions when the outcome is expected to be death or disability. We performed a focused review of literature regarding informed consent in pediatric neurosurgery by searching PubMed and Google Scholar with search terms including "pediatric neurosurgery," "informed consent," and "disability." The literature was focused on patients with diagnoses including spina bifida, neuro-oncology, trauma, and hydrocephalus. Patient perspective elements were physical/mental disability, lack of autonomy, and role in community/society. The family perspective involves caregiver burden, emotional toll, and financial impact. Societal considerations include the availability of public resources for disabled children, large-scale financial cost, and impacts on global health. Practical conversational steps with patients/caregivers include opening the discussion, information provision and acknowledgement of uncertainty, assessment of understanding and clarifying questions, decision-making, and decision maintenance, all while remaining sensitive to the emotional burden commensurate with these decisions. The "death or disability" paradigm represents a common challenge to informed consent in pediatric neurosurgery. Patient, family, and societal factors that inform surrogate decisions vary and sometimes conflict. Pediatric neurosurgeons must use a comprehensive approach to address the informational and relational needs of caregivers during the informed consent process.

Morning glory disc anomaly and its implications in moyamoya arteriopathy: a retrospective case series.

OBJECTIVE: Morning glory disc anomaly (MGDA), a congenital abnormality of the optic nerve, may be associated with moyamoya arteriopathy, a cerebrovascular abnormality. In this study, the authors aimed to define the temporal evolution of cerebrovascular arteriopathy in patients with MGDA to characterize a rational strategy for screening and management over time. METHODS: The records of pediatric neurosurgical patients at two academic institutions were retrospectively reviewed to identify cases of cerebral arteriopathy and MGDA, including radiographic and clinical records documenting patient outcomes of medical and surgical management. RESULTS: Thirteen cases of moyamoya syndrome (MMS) associated with MGDA were identified in 13 children aged 0.6-17 years. The pattern of arteriopathy resembled that of non-MGDA MMS, with predominantly anterior circulation involvement. The arteriopathy lateralized with the MGDA, although 3 patients also had contralateral involvement. The overall group was followed for a median of 3.2 years. Radiological biomarkers of cerebral ischemia were applied to guide surgical decisions, and more than half of the patients (7 of 13) had evidence of stroke or progression on serial imaging. Nine patients underwent revascularization surgery, and 4 were managed medically. CONCLUSIONS: Cerebral arteriopathy observed in association with MGDA resembles MMS seen in patients without MGDA and is dynamic, with progression observed over months to years and an associated risk of cerebral ischemia that indicates a role for surgical revascularization. Radiological biomarkers may augment clinical data to identify candidates for revascularization surgery.

Flexible neuroendoscopy for endoscopic third ventriculostomy and fourth ventricular arachnoid cyst fenestration in an infant.

Arachnoid cysts of the fourth ventricle are rarely reported. Management options include CSF diversion, cyst fenestration, or cyst excision. Fenestration can be done via open microsurgical technique or endoscopically with or without simultaneous third ventriculostomy; and both rigid and flexible endoscopy have been used successfully. However, application of this treatment modality in pediatric patients is not well described. Therefore, to their knowledge, the authors report the first successful treatment of a fourth ventricular arachnoid cyst with a single frontal burr hole entry point for third ventriculostomy and fourth ventricular arachnoid cyst fenestration performed using flexible neuroendoscopy. The patient was a 13-month-old boy presenting with progressive macrocephaly. The authors review their technique, discuss special considerations when using this approach, and include an annotated intraoperative video for demonstration to help instruct and guide management. The authors demonstrate with an example that a single frontal burr hole entry point for flexible endoscopic third ventriculostomy and navigation through a dilated cerebral aqueduct for fourth ventricular arachnoid cyst fenestration is a viable treatment for symptomatic fourth ventricular arachnoid cysts in children.

Germline genetic mutations in pediatric cerebrovascular anomalies: a multidisciplinary approach to screening, testing, and management.

OBJECTIVE: Genetic alterations are increasingly recognized as etiologic factors linked to the pathogenesis and development of cerebrovascular anomalies. Their identification allows for advanced screening and targeted therapeutic approaches. The authors aimed to describe the role of a collaborative approach to care and genetic testing in pediatric patients with neurovascular anomalies, with the objectives of identifying what genetic testing recommendations were made, the yield of genetic testing, and the implications for familial screening and management at present and in the future. METHODS: The authors performed a descriptive retrospective cohort study examining pediatric patients genetically screened through the Pediatric Neurovascular Program of a single treatment center. Patients 18 years of age and younger with neurovascular anomalies, diagnosed radiographically or histopathologically, were evaluated for germline genetic testing. Patient demographic data and germline genetic testing and recommendation, clinical, treatment, and outcome data were collected and analyzed. RESULTS: Sixty patients were included; 29 (47.5%) were female. The mean age at consultation was 11.0 ± 4.9 years. Diagnoses included cerebral arteriovenous malformations (AVMs) (n = 23), cerebral cavernous malformations (n = 19), non-neurofibromatosis/non-sickle cell moyamoya (n = 8), diffuse cerebral proliferative angiopathy, and megalencephaly-capillary malformation. Of the 56 patients recommended to have genetic testing, 40 completed it. Genetic alterations were found in 13 (23%) patients. Four patients with AVMs had RASA1, GDF2, and ACVRL1 mutations. Four patients with cavernous malformations had Krit1 mutations. One with moyamoya disease had an RNF213 mutation. Three patients with megalencephaly-capillary malformation had PIK3CA mutations, and 1 patient with a cavernous sinus lesion had an MED12 mutation. The majority of AVM patients were treated surgically. Patients with diffuse cerebral proliferative angiopathy were treated medically with sirolimus. At-risk relatives of 3 patients positive for genetic anomalies had also been tested. CONCLUSIONS: This study demonstrates a role for exploring genetic alterations in the identification and treatment of pediatric neurovascular disease pathogenesis. Germline genetic mutations were found in almost one-quarter of the patients screened in this study, results that helped to identify medically targeted treatment modalities for some pediatric neurovascular patients. Insight into the genetic etiology of vascular anomalies may provide broader clinical implications for risk assessment, family screening, follow-up surveillance, and medical management.

Vagus nerve stimulator revision in pediatric epilepsy patients: a technical note and case series.

INTRODUCTION: Vagus nerve stimulation (VNS) is an adjunctive treatment in children with intractable epilepsy. When lead replacement becomes necessary, the old leads are often truncated and retained and new leads are implanted at a newly exposed segment of the nerve. Direct lead removal and replacement are infrequently described, with outcomes poorly characterized. We aimed to describe our experience with feasibility of VNS lead removal and replacement in pediatric patients. METHODS: Retrospective review examined 14 patients, at a single, tertiary-care, children's hospital, who underwent surgery to replace VNS leads, with complete removal of the existing lead from the vagus nerve and placement of a new lead on the same segment of the vagus nerve, via blunt and sharp dissection without use of electrocautery. Preoperative characteristics, stimulation parameters, and outcomes were collected. RESULTS: Mean age at initial VNS placement was 7.6 years (SD 3.5, range 4.5-13.4). Most common etiologies of epilepsy were genetic (5, 36%) and cryptogenic (4, 29%). Lead replacement was performed at a mean of 6.0 years (SD 3.8, range 2.1-11.7) following initial VNS placement. Reasons for revision included VNS lead breakage or malfunction. There were no perioperative complications, including surgical site infection, voice changes, dysphagia, or new deficits postoperatively. Stimulation parameters after replacement surgery at last follow-up were similar compared to preoperatively, with final stimulation parameters ranging from 0.25 mA higher to 1.5 mA lower to maintain baseline seizure control. The mean length of follow-up was 7.9 years (SD 3.5, range 3.1-13.7). CONCLUSION: Removal and replacement of VNS leads are feasible and can be safely performed in children. Further characterization of surgical technique, associated risk, impact on stimulation parameters, and long-term outcomes are needed to inform best practices in VNS revision.

Visual Outcomes After Treatment for Sporadic Optic Pathway Gliomas in Pediatric Patients: A Systematic Review.

OBJECTIVE: Optic pathway gliomas (OPGs) typically occur in the first decade of life and 40%-50% are not associated with neurofibromatosis 1 (NF1) (sporadic). Management strategies are often patient specific because of the variable and unpredictable course. No study has summarized the effect of treatment strategies on visual outcomes in the subset of pediatric patients with sporadic OPG. METHODS: We conducted a systematic review to determine the nature of visual outcomes in pediatric patients with sporadic, non-NF1-associated OPG using the PubMed, Embase, Scopus, Cochrane, and CINAHL Plus databases. Visual outcomes were categorized as improved, unchanged, or deteriorated. RESULTS: Of 1316 results, 31 articles were included. Treatment indications are unknown with full clinical detail. A total of 45.2% (14/31) reported deteriorated outcomes after treatment, 35.5% (11/31) no change, and 19.4% (6/31) improvement. Of radiotherapy studies, 50.0% (4/8) found no change, 37.5% (3/8) deterioration, and 12.5% (1/8) improvement. Of chemotherapy studies, 35.7% (5/14) each showed improvement and deterioration, whereas 28.6% (4/14) showed no change. Of surgical studies, 62.5% (5/8) indicated deterioration, and 37/5% (3/8) indicated no change. The singular study examining observation reported deterioration in visual outcomes. Factors associated with poor visual outcomes included signs and symptoms of visual decline at presentation, involvement of the intraorbital optic nerve, and intracranial hypertension requiring surgery. Causality cannot be determined from systematic review. CONCLUSIONS: Most studies showed that vision in pediatric patients with sporadic OPG is stable to poor after observation, chemotherapy, radiotherapy, or surgery. Chemotherapy may be associated with most favorable visual outcomes.