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OBJECTIVEAlthough hemispherectomy is an effective treatment for children with intractable hemispheric epilepsy syndromes, as many as 40% of patients eventually develop seizure recurrence. The causes of seizure recurrence in these patients are incompletely understood. The authors sought to evaluate the efficacy of hemispherectomy at their center and determine whether contralateral MRI abnormalities can predict seizure recurrence.METHODSA retrospective review of consecutive hemispherectomies performed at Miami Children’s Hospital between January 2000 and June 2014 was performed. Time-to-event analysis was performed. The “event” was defined as any seizures following resective epilepsy surgery (not including seizures in the first postoperative week and auras). Several preoperative variables were analyzed to determine their suitability to predict seizure recurrence following surgery.RESULTSSixty-nine patients (44 boys) with a mean age of 8.2 ± 5.9 years (range 0.1–20.8 years) underwent 72 hemispherectomies; 67 of these were functional hemispherectomies, while another 5 were completion of a previous functional hemispherectomy (2 completions of functional hemispherectomies, 3 anatomical hemispherectomies). The duration of epilepsy was 5.8 ± 5.5 years with 66 cases (91.7%) having daily seizures. Etiology included stroke (n = 28), malformation of cortical development (n = 11), hemimegalencephaly (n = 11), encephalitis (n = 13), and other (n = 7). Engel class I outcome was achieved in 59 (86%) and 56 (81%) patients at 1 and 2 years of follow-up, respectively. The mean time to seizure recurrence was 33.5 ± 31.1 months. In univariate analyses, the absence of contralateral abnormalities on MRI (HR 4.09, 95% CI 1.41–11.89, p = 0.009) was associated with a longer duration of seizure freedom. The presence of contralateral MRI abnormalities was associated with contralateral ictal seizures on preoperative scalp EEG (p = 0.002). Fifteen patients experienced 20 complications (20/72, 27.8%), including the development of hydrocephalus necessitating CSF diversion in 9 cases (13%), hygroma in 1, hemispheric edema in 1, aseptic meningitis in 2, postoperative hemorrhage in 2, infection in 2, ischemic stroke in 2, and blood transfusion–contracted hepatitis C in 1 case.CONCLUSIONSPatients with bihemispheric abnormalities, as evidenced by contralateral MRI abnormalities, have a higher risk of earlier seizure recurrence following functional hemispherectomy.

BACKGROUND Malignant peripheral nerve sheath tumors (MPNST) are rare tumors found throughout the body, with their clinical course in children still to be completely understood. Correspondingly, this study aimed to determine survival outcomes and specific clinical predictors of survival in this demographic from a large national database. METHODS All MPNST patients aged ≤18 year in the U.S. National Cancer Database (NCDB) between 2005-2016 were retrospectively reviewed. Data were summarized and overall survival (OS) was modeled using Kaplan-Meier and Cox regression analyses. RESULTS A total of 251 pediatric MPNST cases were identified. Overall, mean age at diagnosis was 13.1 years (range, 1-18) with there being 132 (53%) females and 119 (47%) males. There were 84 (33%) MPNSTs located in extremities, 127 (51%) less than 1cm in size, and 22 (9%) have metastasis at diagnosis. In terms of treatment, surgery was pursued in 187 (74%) patients, chemotherapy in 116 (46%) patients, and radiation therapy in 129 (61%) patients. Five-year overall survival was estimated to be 52% (95% CI, 45-59%), and with median survival of 64 months (range, 36-136). Multivariate regression revealed older age (HR 1.10, P< 0.01), with metastases at time of diagnosis (HR 2.14, P=0.01), and biopsy only (HR 2.98, P< 0.01) all significantly and independently predicted shorter overall survival. Chemotherapy and radiation therapy were not statistically significant. CONCLUSIONS Pediatric MPNSTs are rare malignant entities, and only approximately half of patients will survive to five years. There remains a clear survival benefit in pursuing maximal safe resection in these patients. As such, judicious workup with meticulous surgical resection by an expert team should then be considered the standard of care for these tumors in children.

Purpose: Postoperative radiation therapy (RT) is commonly used for World Health Organization grade II-III intracranial ependymoma. Clinicians generally aim to begin RT ≤5 weeks after surgery, but postoperative recovery and need for second look surgery can delay the initiation of adjuvant therapy. On ACNS 0831, patients were required to enroll ≤8 weeks after initial surgery and begin adjuvant therapy within 3 weeks after enrollment. The purpose of this study was to determine the optimal timing of RT after surgery. Methods and Materials: The National Cancer Database was queried for patients (aged 1-39 years) with localized World Health Organization grade II-III intracranial ependymoma treated with surgery and postoperative RT. Overall survival (OS) curves were plotted based on RT timing (≤5 weeks, 5-8 weeks, and >8 weeks after surgery) and were compared by log-rank test. Factors associated with OS were identified by multivariate analysis. After 2009, complete data were available on whether patients underwent gross total resection or subtotal resection. Planned subset analysis was performed to examine the effect of RT timing on OS in patients with known extent of resection. Results: In the final analytical data set of 1043 patients, no difference in 3-year OS was observed in patients who initiated RT ≤5 weeks, 5 to 8 weeks, and >8 weeks after surgery (89.8% vs 89.1% vs 88.4%; P = .796). On multivariate analysis, grade III tumors (hazard ratio, 2.752; 95% confidence interval, 1.969-3.846, P < .001) and subtotal resection (hazard ratio, 2.253; 95% confidence interval, 1.405-3.611, P < .001) were significantly associated with reduced OS. Timing of RT, total RT dose, age, and other factors were not significant. These findings were affirmed in the subset of patients treated between 2010 and 2016, when extent of resection was routinely recorded. Conclusions: Delayed postoperative RT was not associated with inferior survival in patients with intracranial ependymoma. Delayed RT initiation may be acceptable in patients who require longer postoperative recovery or referral to an appropriate RT center, but should be minimized whenever practical.

BACKGROUND: H3 K27M-mutant diffuse midline glioma is a fatal malignancy with no proven medical therapies. The entity predominantly occurs in children and young adults. ONC201 is a small molecule selective antagonist of dopamine receptor D2/3 (DRD2/3) with an exceptional safety profile. Following up on a durable response in the first H3 K27M-mutant diffuse midline glioma patient who received ONC201 (NCT02525692), an expanded access program was initiated. METHODS: Patients with H3 K27M-mutant gliomas who received at least prior radiation were eligible. Patients with leptomeningeal spread were excluded. All patients received open-label ONC201 orally once every week. Safety, radiographic assessments, and overall survival were regularly assessed at least every 8 weeks by investigators. As of August 2018, a total of 18 patients with H3 K27M-mutant diffuse midline glioma or DIPG were enrolled to single patient expanded access ONC201 protocols. Among the 18 patients: seven adult (>20 years old) and seven pediatric (

OBJECTIVE Carotid body tumors (CBTs), extraadrenal paragangliomas, are extremely rare neoplasms in children that often require multimodal surgical treatment, including preoperative anesthesia workup, embolization, and resection. With only a few cases reported in the pediatric literature, treatment paradigms and surgical morbidity are loosely defined, especially when carotid artery infiltration is noted. Here, the authors report two cases of pediatric CBT and provide the results of a systematic review of the literature. METHODS The study was divided into two sections. First, the authors conducted a retrospective review of our series of pediatric CBT patients and screened for patients with evidence of a CBT over the last 10 years (2007–2017) at a single tertiary referral pediatric hospital. Second, they conducted a systematic review, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, of all reported cases of pediatric CBTs to determine the characteristics (tumor size, vascularity, symptomatology), treatment paradigms, and complications. RESULTS In the systematic review (n = 21 patients [includes 19 cases found in the literature and 2 from the authors’ series]), the mean age at diagnosis was 11.8 years. The most common presenting symptoms were palpable neck mass (62%), cranial nerve palsies (33%), cough or dysphagia (14%), and neck pain (19%). Metastasis occurred only in 5% of patients, and 19% of cases were recurrent lesions. Only 10% of patients presented with elevated catecholamines and associated sympathetic involvement. Preoperative embolization was utilized in 24% of patients (external carotid artery in 4 and external carotid artery and vertebral artery in 1). Cranial nerve palsies (cranial nerve VII [n = 1], IX [n = 1], X [n = 4], XI [n = 1], and XII [n = 3]) were the most common cause of surgical morbidity (33% of cases). The patients in the authors’ illustrative cases underwent preoperative embolization and balloon test occlusion followed by resection, and both patients suffered from transient Horner’s syndrome after embolization. CONCLUSIONS Surgical management of CBTs requires an extensive preoperative workup, anesthesia, and multimodal surgical management. Due to a potentially high rate of surgical morbidity and vascularity, balloon test occlusion with embolization may be necessary in select patients prior to resection. Careful thorough preoperative counseling is vital to preparing families for the intensive management of these children. ABBREVIATIONS BTO = balloon test occlusion; CBT = carotid body tumor; CN = cranial nerve; ECA = external carotid artery; ICA = internal carotid artery; MIBG = iodine-123-meta-iodobenzylguanidine; PRISMA = Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

PURPOSE/OBJECTIVE(S) Pediatric brain tumor patients are at high risk of developing neurocognitive deficits following treatment. The perihippocampal subventricular zone contains a niche of radiosensitive neural progenitor cells linked to memory development, and radiotherapy (RT) to this brain substructure has been associated with neurocognitive impairment in randomized trials. In this prospective study, 3D volumetric MRIs were obtained in pediatric brain tumor patients at baseline and during follow-up to measure volumetric changes in multiple brain substructures along with neurocognitive, endocrine, quality-of-life, and exploratory biomarker assessments. In this planned interim analysis, we model early outcomes for change in hippocampal volume at 6 months following RT. MATERIALS/METHODS As of 2/26/2021, 47 patients had enrolled on this prospective study and 36 had completed their 6-month follow-up assessments after fractionated intensity-modulated proton therapy (IMPT) for primary brain and skull base tumors. Left and right hippocampus volumes were independently measured on T1 sagittal precontrast MRI using automated software at baseline and 6-months after RT and were compared to manual physician contours. The relationship between mean hippocampus dose and change in volume was assessed by Pearson's correlation coefficient. The effect of mean hippocampus dose on change in volume was assessed for mean doses < 10 Gy and ≥10 Gy by t-test. A linear mixed-effects (LME) model was applied to evaluate other predictors associated with change in hippocampus volume, assuming random effects of subjects. Potential factors considered were age, gender, tumor location, focal vs. whole brain RT, prior craniotomy, and chemotherapy. RESULTS Mean hippocampus dose was strongly correlated with change in hippocampus volume at 6 months following RT (r = -0.727, 95% CI [-0.820 -0.596], P < 0.001). Hippocampus volumes and observed changes over time were similar between the software and physician-delineated contours. A significant reduction in hippocampus volume was observed for mean doses ≥10 Gy (mean Δ -10.8% ± 5.5%, P < 0.001), while no significant change in volume was observed for mean doses < 10 Gy (mean Δ +0.7% ± 3.9%). The LME model demonstrated that only mean hippocampus dose was significantly associated with change in hippocampus volume (P < 0.001). The final model predicted a -3.4% change in hippocampus volume for every 10 Gy increase in mean dose. Regression diagnostics showed no evidence of lack-of-fit and no patterns in residuals. CONCLUSION Change in hippocampus volume was correlated with hippocampus mean dose at 6 months following RT. A significant reduction in hippocampus volume was observed for mean doses ≥10 Gy compared to no significant change at mean doses < 10 Gy. Future analyses from this study will assess volume change in this and other brain substructures over time as a function of radiation dose and will correlate these findings with measured neurocognitive and other late effects.

Deep learning (DL) is a widely applied mathematical modeling technique. Classically, DL models utilize large volumes of training data, which are not available in many healthcare contexts. For patients with brain tumors, non-invasive diagnosis would represent a substantial clinical advance, potentially sparing patients from the risks associated with surgical intervention on the brain. Such an approach will depend upon highly accurate models built using the limited datasets that are available. Herein, we present a novel genetic algorithm (GA) that identifies optimal architecture parameters using feature embeddings from state-of-the-art image classification networks to identify the pediatric brain tumor, adamantinomatous craniopharyngioma (ACP). We optimized classification models for preoperative Computed Tomography (CT), Magnetic Resonance Imaging (MRI), and combined CT and MRI datasets with demonstrated test accuracies of 85.3%, 83.3%, and 87.8%, respectively. Notably, our GA improved baseline model performance by up to 38%. This work advances DL and its applications within healthcare by identifying optimized networks in small-scale data contexts. The proposed system is easily implementable and scalable for non-invasive computer-aided diagnosis, even for uncommon diseases.

Adamantinomatous craniopharyngioma (ACP) is a biologically benign but clinically aggressive lesion that has a significant impact on quality of life. The incidence of the disease has a bimodal distribution, with peaks occurring in children and older adults. Our group previously published the results of a transcriptome analysis of pediatric ACPs that identified several genes that were consistently overexpressed relative to other pediatric brain tumors and normal tissue. We now present the results of a transcriptome analysis comparing pediatric to adult ACP to identify biological differences between these groups that may provide novel therapeutic insights or support the assertion that potential therapies identified through the study of pediatric ACP may also have a role in adult ACP. Using our compiled transcriptome dataset of 27 pediatric and 9 adult ACPs, obtained through the Advancing Treatment for Pediatric Craniopharyngioma Consortium, we interrogated potential age-related transcriptional differences using several rigorous mathematical analyses. These included: canonical differential expression analysis; divisive, agglomerative, and probabilistic based hierarchical clustering; information theory based characterizations; and the deep learning approach, HD Spot. Our work indicates that there is no therapeutically relevant difference in ACP gene expression based on age. As such, potential therapeutic targets identified in pediatric ACP are also likely to have relvance for adult patients.

Additional file 1: Figure S1. Log fold change versus p-value for therapeutic targets across ACP age groups compared to GTEx normal pituitary dataset. Table S1. Dataset Demographics and CTNNB1 Mutation Status. Hyphen values indicate data not available. WT: Wild Type; Age at Dx: Age at Diagnosis.

OBJECTIVEDespite increasing adoption of endoscopic techniques for repair of nonsagittal single-suture craniosynostosis, the efficacy and safety of the procedure relative to established open approaches are unknown. In this systematic review the authors aimed to directly compare open surgical and endoscope-assisted techniques for the treatment of metopic, unilateral coronal, and lambdoid craniosynostosis, with an emphasis on quantitative reported outcomes.METHODSA literature search was performed in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant articles were identified from 3 electronic databases (MEDLINE, EMBASE, and CENTRAL [Cochrane Central Register of Controlled Trials]) from their inception to August 2017. The quality of methodology and bias risk were assessed using the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies.RESULTSOf 316 screened records, 7 studies were included in a qualitative synthesis of the evidence, of which none were eligible for meta-analysis. These reported on 111 unique patients with metopic, 65 with unilateral coronal, and 12 with lambdoid craniosynostosis. For all suture types, 100 (53%) children underwent endoscope-assisted craniosynostosis surgery and 32 (47%) patients underwent open repair. These studies all suggest that blood loss, transfusion rate, operating time, and length of hospital stay were superior for endoscopically treated children. Although potentially comparable or better cosmetic outcomes are reported, the paucity of evidence and considerable variability in outcomes preclude meaningful conclusions.CONCLUSIONSLimited data comparing open and endoscopic treatments for metopic, unilateral coronal, and lambdoid synostosis suggest a benefit for endoscopic techniques with respect to blood loss, transfusion, length of stay, and operating time. This report highlights shortcomings in evidence and gaps in knowledge regarding endoscopic repair of nonsagittal single-suture craniosynostosis, emphasizing the need for further matched-control studies.

BACKGROUND Diffuse leptomeningeal glioneuronal tumor (DLGNT), also known as oligodendrogliomatosis, is a rare neuro-oncologic condition along the neuraxis that remains poorly understood in children. We sought to describe our institutional experience and quantitively summarize the clinical survival and prognostic features of DLGNT in the pediatric population across the contemporary literature. METHODS We report four institutional cases of pediatric DLGNT diagnosed between 2000-2020 based on retrospective review of our records, and performed a comprehensive literature search for published cases from 2000 onwards to create an integrated cohort for analysis. Kaplan-Meier estimations, Fisher’s exact test, and logistic regression were utilized to interrogate the data. RESULTS Our overall integrated cohort consisted of 54 pediatric DLGNT patients, with 19 (35%) female and 35 (65%) male patients diagnosed at an average age of 6.4 years (range, 1.3-17 years) by means of surgical biopsy. Chemotherapy was used in 45 cases (83%), and mean follow-up time of 54 months (range, 3-204). Across the entire cohort, overall survival 1 month after diagnosis was 96% (95% CI 86-99%), and by 10 years was 69% (95% CI 49-82%). On multivariate analysis of complete data, chemotherapy treatment (HR=0.23, P=0.04) was statistically predictive of longer overall survival. When including limited data, longer duration of symptoms by presentation (HR=1.03, P=0.03) was statistically predictive of shorter overall survival. CONCLUSIONS This is the first quantitative study of pediatric DLGNT clinical course. More than 2-out-of-3 pediatric DLGNT patients survive beyond one decade. Chemotherapy is statistically associated with longer survival in DLGNT pediatric patients and should form the core of any treatment regimen in this setting. Early detection by means of judicious imaging and surgical biopsy for tissue diagnosis can lead to earlier treatment and likely superior outcomes.

PURPOSE/OBJECTIVES MRIs in pediatric and adult brain tumor patients (Age< 35) were prospectively collected at baseline and during follow-up to measure volumetric changes in multiple brain substructures with neurocognitive, laboratory, and quality-of-life assessments. In this planned interim analysis, we model early outcomes for change in hippocampal volume at 6 months following radiotherapy. MATERIALS AND METHODS As of 5/15/2021, 50 patients enrolled on this prospective study and 41 completed 6-month post-treatment assessments after fractionated intensity-modulated proton therapy. Left and right hippocampus volumes were independently measured on T1 sagittal precontrast MRI at baseline and 6-months after radiotherapy using both automated software and physician-delineated contours. The relationship between mean hippocampus dose and change in volume was assessed by Pearson’s correlation coefficient. A linear mixed-effects model was applied to evaluate other predictors associated with change in hippocampal volume, assuming random effects of subjects. RESULTS Mean hippocampus dose was strongly correlated with change in hippocampal volume at 6 months following radiotherapy (r=−0.727, 95% CI [-0.820,-0.596], p< 0.001). Changes in hippocampal volumes over time were similar between software and physician contours. Hippocampal volume was significantly reduced for mean doses ≥10 Gy (mean Δ -10.8% ± 5.5%, p< 0.001), while no significant volume change was observed with mean doses < 10 Gy (mean Δ +0.7% ± 3.9%). In the mixed-effects model, only mean hippocampus dose was significantly associated with hippocampal volume change (p< 0.001). The final model predicted a -3.4% change in hippocampal volume for every 10 Gy increase in mean dose. CONCLUSIONS Change in hippocampal volume was correlated with hippocampus mean dose at 6 months following radiotherapy. Future analyses will assess volume change in the hippocampus and other brain substructures over time as a function of radiation dose and correlate with measured neurocognitive and other effects.

Pediatric adamantinomatous craniopharyngioma (ACP) is a highly solid and cystic tumor, often causing substantial damage to critical neuroendocrine structures such as the hypothalamus, pituitary gland, and optic apparatus. Paracrine signaling mechanisms driving tumor behavior have been hypothesized, with IL-6R overexpression identified as a potential therapeutic target. To identify potential novel therapies, we characterized inflammatory and immunomodulatory factors in ACP cyst fluid and solid tumor components. Cytometric bead analysis revealed a highly pro-inflammatory cytokine pattern in fluid from ACP compared to fluids from another cystic pediatric brain tumor, pilocytic astrocytoma. Cytokines and chemokines with particularly elevated concentrations in ACPs were IL-6, CXCL1 (GRO), CXCL8 (IL-8) and the immunosuppressive cytokine IL-10. These data were concordant with solid tumor compartment transcriptomic data from a larger cohort of ACPs, other pediatric brain tumors and normal brain. The majority of receptors for these cytokines and chemokines were also over-expressed in ACPs. In addition to IL-10, the established immunosuppressive factor IDO-1 was overexpressed by ACPs at the mRNA and protein levels. These data indicate that ACP cyst fluids and solid tumor components are characterized by an inflammatory cytokine and chemokine expression pattern. Further study regarding selective cytokine blockade may inform novel therapeutic interventions.

METHODS Through the Advancing Treatment for Pediatric Craniopharyngioma (ATPC) consortium we accumulated preoperative MRIs and tumor RNA for 50 unique ACP patients. MRIs were assessed quantitatively for 28 different features and analyzed using Multiple Factor Analysis (MFA) and optimal clustering was determined via maximization of Bayesian Information Criterion (BIC). Following bulk RNAseq, differential expression and pathway enrichment were performed using standard methodologies (i.e., DESeq2 and GSEA). RESULTS MRI features were well represented in the first 3 dimensions of MFA (variance explained=67.32%); specifically tumor/cyst size, ventricular size, and cyst fluid diffusivity. Using this three-way axis, we identified 3 patient subgroups. Transcriptional differences between these subgroups indicated one group was enriched for DNA damage response and MYC related pathways, one group enriched for SHH, and one group enriched for WNT/β-catenin and EMT-related pathways. CONCLUSION This preliminary work suggests that there may be unique gene expression variants within ACP, which may be identified preoperatively using easily quantifiable MRI parameters. These radiogenomic signatures could provide prognostic information and/or guidance in the selection of antitumor therapies for children with ACP.

BACKGROUND Due to disease and/or treatment-related injury, such as hypothalamic, visual, and endocrine damage, quality of life (QoL) scores after childhood-onset Adamantinomatous Craniopharyngioma (ACP) are among the lowest of all pediatric brain tumors. Decision-making regarding management would be aided by more complete understanding of a patients likely QoL trajectory following intervention. METHODS We retrospectively analyzed caregiver and patient-reported QoL-instruments from the first 50 patients (ages 1–17 years at diagnosis) enrolled in the international Advancing Treatment for Pediatric Craniopharyngioma (ATPC) consortium. Surveys included 205 pediatric-relevant questions and were completed at diagnosis, and 1- and 12-months following diagnosis. Using Multiple Correspondence Analysis (MCA), these categorical QoL surveys were interrogated to identify time-dependent patient subgroups. Additionally, custom deep learning classifiers were developed using Google’s TensorFlow framework. RESULTS By representing QoL data in the reduced dimensionality of MCA-space, we identified QoL subgroups that either improved or declined over time. We assessed differential trends in QoL responses to identify variables that were subgroup specific (Kolmogorov-Smirnov p-value < 0.1; n=20). Additionally, our optimized deep learning classifier achieved a mean 5-fold cross-validation area under precision-recall curve score > 0.99 when classifying QoL subgroups at 12 month follow-up, using only baseline data. CONCLUSIONs This work demonstrates the existence of time-dependent QoL-based ACP subgroups that can be inferred at time-of-diagnosis via machine learning analyses of baseline survey responses. The ability to predict an ACP patient’s QoL trajectory affords caregivers valuable information that can be leveraged to maximize that patient’s psychosocial state and therefore improve overall therapy.

BACKGROUND Methotrexate has been used for intrathecal administration in leukemia as well as embryonal CNS tumors in children. Concerns about neurologic side effects including leukoencephalopathy, demyelination, and seizures have limited the use of methotrexate following exposure to focal radiation. OBJECTIVE To evaluate and determine safety of Intraventricular administration of Methotrexate in pediatric patients with recurrent malignant brain tumors along with systemic Topotecan and Cyclophosphamide after exposure to prior radiation therapy. DESIGN/METHOD: Patients with recurrent cerebellar embryonal tumors after standard treatment that included radiation were enrolled on this IRB approved phase 2 study. An Ommaya reservoir was inserted in the lateral ventricle and used to administer 4 daily doses of methotrexate (2 mg/dose) along with (Topotecan [0.75mg/m2/day] and Cyclophosphamide [250 mg/m2/day]). A neurological evaluation was performed at baseline and daily during the intraventricular administration of the Methotrexate, this evaluation was repeated prior to each subsequent cycle and at completion of the protocol. RESULTS Three patients (age range 3–20) received 2–3 cycles of intra-Ommaya Methotrexate and Topotecan/Cyclophosphamide. No MRI demyelination or white matter changes were seen after completion of the intraventricular Methotrexate therapy. None of the patients enrolled on this trial had adverse effects related to the therapy regimen received. Clinical neurological status was unchanged during the entire course of the treatment and upon completion of the scheduled therapy. CONCLUSION Intraventricular administration of daily low dose Methotrexate is well tolerated in children with recurrent embryonal CNS tumors who had prior exposure to radiation.

INTRODUCTION Postoperative radiotherapy is commonly given for WHO Grade 2–3 intracranial ependymoma. Clinicians generally aim to begin radiotherapy ≤5 weeks following surgery, but the optimal timing remains uncertain. METHODS The National Cancer Database was queried for patients (age ≤39 years) with localized WHO Grade 2–3 intracranial ependymoma treated with surgery and postoperative radiotherapy. Multivariable logistic regression was used to identify factors associated with delayed postoperative radiotherapy, defined as starting >8 weeks after surgery. Overall survival (OS) curves were plotted based on radiotherapy timing (≤5 weeks, 5–8 weeks, and >8 weeks after surgery) and compared by log-rank test. Multivariate analysis (MVA) was used to identify factors associated with OS. RESULTS In the final analytic set of 1,043 patients, age ≥21 years (OR 2.07, 95% CI 1.56–2.74) and WHO Grade 2 tumors (OR 1.41, 95% CI 1.08–1.85) were significantly associated with delayed time to adjuvant radiotherapy. No difference in 3-year OS was observed in patients who initiated radiotherapy ≤5 weeks, 5–8 weeks, and >8 weeks after surgery (89.8% vs. 89.1% vs. 88.4%; p= 0.796). On MVA, anaplastic histology (HR 2.414, 95% CI 1.784–3.268, p CONCLUSION Delayed postoperative radiotherapy was not associated with inferior survival in patients with intracranial ependymoma, suggesting delayed radiotherapy initiation may be considered in patients requiring longer postoperative recovery or referral to an appropriate radiotherapy center.

OBJECTIVEIn this systematic review and meta-analysis the authors aimed to directly compare open surgical and endoscope-assisted techniques for the treatment of sagittal craniosynostosis, focusing on the outcomes of blood loss, transfusion rate, length of stay, operating time, complication rate, cost, and cosmetic outcome.METHODSA literature search was performed in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant articles were identified from 3 electronic databases (MEDLINE, EMBASE, and CENTRAL [Cochrane Central Register of Controlled Trials]) from their inception to August 2017. The quality of methodology and bias risk were assessed using the Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies. Effect estimates between groups were calculated as standardized mean differences with 95% CIs. Random and fixed effects models were used to estimate the overall effect.RESULTSOf 316 screened records, 10 met the inclusion criteria, of which 3 were included in the meta-analysis. These studies reported on 303 patients treated endoscopically and 385 patients treated with open surgery. Endoscopic surgery was associated with lower estimated blood loss (p < 0.001), shorter length of stay (p < 0.001), and shorter operating time (p < 0.001). From the literature review of the 10 studies, transfusion rates for endoscopic procedures were consistently lower, with significant differences in 4 of 6 studies; the cost was lower, with differences ranging from $11,603 to $31,744 in 3 of 3 studies; and the cosmetic outcomes were equivocal (p > 0.05) in 3 of 3 studies. Finally, endoscopic techniques demonstrated complication rates similar to or lower than those of open surgery in 8 of 8 studies.CONCLUSIONSEndoscopic procedures are associated with lower estimated blood loss, operating time, and days in hospital. Future long-term prospective registries may establish advantages with respect to complications and cost, with equivalent cosmetic outcomes. Larger studies evaluating patient- or parent-reported satisfaction and optimal timing of intervention as well as heterogeneity in outcomes are indicated.

Sinusoidal obstruction syndrome (SOS) in the pediatric population is not limited to a well-defined group of patients who undergo autologous stem cell transplantation. We describe the clinical characteristics of five patients with history of medulloblastoma who developed SOS during treatment as per Head Start (HS) regimens. A chart review of 31 patients from 2006 to 2017 revealed that five patients (16.1%) developed SOS during the course of their therapy (2 patients were enrolled on HS IV). The median age at diagnosis was 2.5 years (range 2-5 years). All three patients diagnosed in the era of HSII/III developed SOS in transplant setting. The other 2 patients on HS IV developed SOS during the induction chemotherapy cycles. In the follow-up period, one patient developed metastatic disease 2 years after completion of therapy. Another patient died from pulmonary fibrosis 4 years post-transplant. Two patients developed fibronodular hyperplasia of the liver on further imaging. The dose of carboplatin for the 3 patients treated as per HSII/III was dosed by the AUC using the Calvert method. The remaining 2 patients had received the induction chemotherapy cycles (second and third) based on the square meter dose on the HS IV guidelines; one of them continued on the same regimen after the dose was adjusted to weight based in the subsequent cycles. Dose calculation based on the weight and age of young patients, particularity those who are under five should be taken into consideration in future studies. Long term consequences of severe SOS should be monitored.

Sickle cell disease (SCD) is an autosomal recessive hematological disorder, characterized by sickling of the red blood cells in response to a hypoxic stress and vaso-occlusive crises. It is associated with moyamoya-like changes on cerebral angiographic imaging in 43% of patients. Cerebral aneurysms, arteriovenous malformations, and dural arteriovenous fistulas (AVFs) have been described in association with SCD and moyamoya disease. However, the description of a pial AVF (pAVF) in a patient with SCD and/or moyamoya formation has not yet been reported. The authors present the case of a 15-year-old boy with SCD-associated moyamoya disease harboring a pAVF who developed a de novo venous aneurysm 8 months after undergoing indirect superficial temporal artery-middle cerebral artery (MCA) bypass that was complicated by bilateral ischemia of the MCA territory. The pAVF was successfully treated with transarterial embolization using Onyx. The authors describe the possible pathophysiological mechanisms and management strategies for this rare occurrence.

OBJECTIVEAlthough endoscopic third ventriculostomy (ETV) with choroid plexus cauterization (CPC) has gained increasing prominence in the management of hydrocephalus caused by intraventricular hemorrhage of prematurity, the rates of long-term shunt independence remain low. Furthermore, limited evidence is available to identify infants who might benefit from the procedure. The authors tested the hypothesis that elevated venous pressure that results from comorbid cardiac disease might predispose patients to ETV/CPC failure and shunt dependence.METHODSA retrospective analysis was performed on a consecutive series of 48 infants with hydrocephalus who underwent ETV/CPC and also underwent preoperative echocardiography between 2007 and 2014. Comorbid cardiac abnormalities that are known to result in elevated right heart pressure were reviewed. Associations between ETV/CPC success and the presence of pulmonary hypertension, right ventricular hypertrophy, left-to-right shunting, ventricular septal defect, or patent ductus arteriosus were determined using multivariate logistic regression analysis.RESULTSOf the 48 children who met the inclusion criteria, ETV/CPC failed in 31 (65%). In univariate analysis, no single echocardiogram abnormality was associated with shunt failure, but the presence of 2 or more concurrent echocardiogram abnormalities was associated with ETV/CPC failure (17 [85%] of 20 vs 14 [50%] of 28, respectively; p = 0.018). In multivariate logistic regression analysis, when the authors adjusted for the child’s ETV success score, the presence of 2 abnormalities remained independently associated with poor outcome (2 or more echocardiogram abnormalities, OR 0.13, 95% CI 0.01–0.7, p = 0.032; ETV success score, OR 1.1, 95% CI 1–1.2, p = 0.05).CONCLUSIONSIn this study, cardiac abnormalities were inversely associated with the success of ETV/CPC in infants with hydrocephalus of prematurity. ETV/CPC might not be as efficacious in patients with significant cardiac anomalies. These results provide a basis for future efforts to stratify surgical candidacy for ETV/CPC on the basis of comorbid abnormalities. Proper cardiac physiological pressure monitoring might help elucidate the relationship between cardiac abnormalities and hydrocephalus.

Cognard Type V dural arteriovenous fistulas (dAVFs) are a unique type of cranial vascular malformation characterized by congestion of the perimedullary venous system that may lead to devastating spinal cord pathology if left untreated. The authors present the first known case of a pediatric patient diagnosed with a Type V dAVF. A 14-year-old girl presented with a 3-week history of slowly progressive unilateral leg weakness that quickly progressed to bilateral leg paralysis, sphincter dysfunction, and complete sensory loss the day of her presentation. MRI revealed an extensive T2 signal change in the cervical spine and tortuous perimedullary veins along the entire length of the cord. An emergency cranial angiogram showed a Type V dAVF fed by the posterior meningeal artery with drainage into the perimedullary veins of the cervical spine. The fistula was not amenable to embolization because vascular access was difficult; therefore, the patient underwent urgent suboccipital craniotomy and ligation of the arterialized venous drainage from the fistula. The patient’s clinical course immediately reversed; she had a complete recovery over the course of a year, and she remains asymptomatic at the 2-year follow-up. This report adds to a growing body of evidence that describes the diverse and unpredictable nature of Type V dAVFs and highlights the need to obtain a cranial angiogram in pediatric patients with unexplained myelopathy and cervical cord T2 signal change on MRI.

BACKGROUND Pleomorphic xanthoastrocytoma (PXA) and anaplastic pleomorphic xanthoastrocytoma (APXA) are two types of rare astrocytomas in pediatrics. There is limited literature reporting their outcomes. METHODS A retrospective analysis of pediatric patients with diagnosis of PXA and APXA treated at Nicklaus Children’s Hospital was conducted using descriptive measures. RESULTS A chart review of patients with brain tumors from 2001 to 2019 revealed that 13 patients (median age 6 years, range 2–17 years) were diagnosed with non-metastatic PXA (n=12) and APXA (n=1). Six patients (46%) were male. Clinical presentation included seizures (n=8), headaches (n=2) cranial nerve palsies (n=2). Diagnostic imaging showed tumor in the temporal lobe (n=5), parietal lobe (n=2), temporoparietal lobe (n=2), frontal lobe (n=1), occipital lobe (n=1), others (n=2). BRAF V600E mutation were identified in three of five analyzed tumors including PXA (n=4) and APXA (n=1). Surgical intervention consisted of gross total resection (n=8) and near/subtotal resection (n=5). Ten patients (76%) required a second surgery (median 2; range 1–4) due to local recurrence. The median time to recurrence was 3 years (range 6 months - 7 years). Three patients (23%) had malignant transformation of PXA, which occurred three to eight years from the initial surgery; one of them also had extensive spinal metastasis. Focal radiation was given to six patients (46%) due to multiple recurrence (n=2), malignant transformation (n=3), APXA (n=1). At a median follow up of 8 years (range 3 to 20 years), eight patients remain alive, three patients had lost to follow up, two patients died from progressive disease. Long-term sequelae varied as follows; seizures (n=5), motor weakness (n=4), cranial nerve palsies (n=2), and learning disability (n=1). CONCLUSION PXA is associated with high local recurrence rate and uncommonly malignant transformation to APXA in pediatrics, which requires close follow-up due to unpredictable biological behavior of these tumors.

CR-11. PEDIATRIC ADAMANTINOMATOUS CRANIOPHARYNGIOMA CYST FLUID DEMONSTRATES A PRO-INFLAMMATORY MILIEU Andrew Donson2, Andrea Griesinger2, Vladimir Amani2, Richard C.E. Anderson4, Toba N. Niazi3, Michael H. Handler1,2, Nicholas K. Foreman1,2, and Todd C. Hankinson1,2; Children’s Hospital Colorado, Aurora, CO, USA; University of Colorado School of Medicine, Aurora, CO, USA; Nicklaus Children’s Hospital, Miami, FL, USA; Morgan Stanley Children’s Hospital of New York-Presbyterian, New York, NY, USA BACKGROUND: The cyst component of pediatric adamantinomatous craniopharyngioma (ACP) often exerts substantial mass effect, grows unpredictably, and is poorly responsive to radiation therapy. Current cyst-directed therapies mandate surgical intervention. An improved understanding of the drivers of ACP cyst growth may allow for the identification of systemic therapies that can control cyst expansion and improve tumor control and/or our ability to safely undertake radical tumor resection. METHODS: Milliplex cytokine expression analysis was used to compare the cytokine milieu of ACP cyst (n 1⁄4 5) to another common cyst generating pediatric brain tumor, Juvenile Pilocytic Astrocytoma (JPA, n 1⁄4 5). The ratio of cytokine levels in the 2 tumor types was compared. RESULTS: Compared to JPA cysts, all ACP specimens showed a highly pro-inflammatory cytokine pattern. Among the cytokines with elevated expression level ratios in ACP, relative to JPA, were IL-6 (353.9, p 1⁄4 1.23x10); IL-8 (57.6, p 1⁄4 0.04); IL-10 (35.5, p 1⁄4 0.003); TNF-a (8.21, p 1⁄4 0.01); and IL-1b (3.65, p 1⁄4 0.005). CONCLUSIONS: ACP cyst fluid appears to be characterized by a highly pro-inflammatory cytokine expression pattern. Understanding the cellular source of these cytokines and the efficacy of selective cytokine blockade may represent an opportunity for therapeutic intervention. Neuro-Oncology 18:iii18–iii23, 2016. doi:10.1093/neuonc/now068.11 #The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

INTRODUCTION: DIPG is uniformly fatal, with a median survival of 8–9 months. We report the first pediatric patient with H3-K27M mutated DIPG treated with conventional radiotherapy and the small molecule DRD2-antagonist ONC201, with a sustained radiographic and clinical response after 8 months of therapy. CASE: A 10-year-old female presented with House-Brackmann Grade IV facial palsy and unilateral hearing loss in 2/2017. MRI demonstrated a 2.3x2.1x2.7 cm medullopontine tumor. Stereotactic biopsy confirmed H3-K27M mutated diffuse midline glioma. She completed intensity-modulated radiotherapy (59.4 Gy/33 fractions) in 5/2017. MR imaging 1-month post-radiotherapy demonstrated reduction in tumor volume (2.0x1.9x2.7 cm) with persistent Grade IV facial palsy.The patient began oral ONC201 (500 mg weekly) as a single agent in 6/2017 on an IRB-approved compassionate use protocol with MRI every 2 months. ONC201 is a first-in-class DRD2-antagonist that crosses the blood-brain barrier and has shown efficacy in high grade glioma preclinical models through a p53-independent mechanism. Tumor volume sequentially decreased by 30.6, 33.2, and 41.9% over the next three MRIs, reaching 1.8x1.7x1.9 cm at 6 months from initiation of ONC201. Ipsilateral hearing was restored and the facial palsy improved to House-Brackmann Grade I by 16 weeks after starting ONC201. CONCLUSION: The patient remains clinically improved and without adverse events 8 months after starting ONC201 and 11 months from diagnosis. This case provides initial proof-of-concept for this novel agent targeting H3-K27M DIPG. Phase II trials are ongoing to evaluate the efficacy of ONC201 in adult and pediatric patients with H3-K27M gliomas.

Medulloblastomas are malignant brain tumors that arise by transformation of neural progenitor cells in the cerebellum in children. Treatment-related neurotoxicity has created a critical need to identify signaling molecules that can be targeted therapeutically to maximize tumor growth suppression and minimize collateral neurologic injury. In genetically engineered mice, activation of Sonic Hedgehog (Shh) signaling in neural stem cells in the developing cerebellum induces medulloblastomas. Hepatocyte growth factor (HGF) and its cell surface receptor c-Met are highly expressed in human medulloblastomas, and elevated levels of c-Met and HGF mRNA predict an unfavorable prognosis for patients. HGF is neuroprotective for cerebellar granule cells and promotes growth of human medulloblastoma cells in culture and in murine xenografts. We modeled the ability of HGF to induce medulloblastomas in mice using a version of the RCAS/tv-a system that allows gene transfer to cerebellar neural progenitors during their postnatal expansion phase when these cells are highly susceptible to transformation. Here, we report a high frequency of medulloblastoma formation in mice after postnatal expression of HGF in cooperation with Shh. Some tumors showed neurocytic differentiation similar to that in human nodular medulloblastomas with activated Shh signaling. Systemic administration of a monoclonal antibody against HGF prolonged survival of mice bearing Shh + HGF–induced medulloblastomas by stimulating apoptosis. These findings indicate a role for HGF in medulloblastoma initiation and growth and show efficacy of HGF-targeted therapy in a mouse model of endogenously arising tumors. [Cancer Res 2008;68(19):7838–45]

Background: Herpes simplex virus encephalitis (HSVE) is the most morbid clinical syndrome associated with the human herpes virus. Despite treatment with appropriate dosages of acyclovir, neurologic relapse of HSV infection have been reported after cranial surgery. Rarely, neurological deterioration due to postinfectious inflammatory response without demonstrable HSV reactivation may recur following cranial surgery. Case Description: We report a case of a 17-year-old girl who presented with a HSVE relapse on the 6 th postoperative day following resective surgery for medically refractory epilepsy and review the literature. Postinfectious inflammatory reaction may be the underlying mechanism in cases with no HSV identified on cerebrospinal fluid (CSF) or brain polymerase chain reaction (PCR), such as in the current case. Conclusion: HSVE must be suspected in patients with previous history of HSVE and postoperative fever associated with an altered state of consciousness and/or seizures. Considering the high mortality and morbidity rates associated with HSVE, an adequate prophylactic administration of acyclovir should be considered for patients with previous history of HSVE undergoing neurosurgical procedures, especially when surgery involves the site of a previous herpetic lesion.

BACKGROUND: Adamantinomatous Craniopharyngioma (ACP) is associated with considerable short and long-term morbidity. There are currently no well-established directed therapies. Recent studies demonstrated pro-inflammatory characteristics in both the solid and cyst compartments, but no data have examined whether immunosuppressive mechanisms are active in these tumors. METHODS: This study utilized a variety of platforms to examine immunosuppressive markers in cyst fluid and associated solid tumor components of ACP. Analyte levels in ACP were compared with other common pediatric brain tumors and normal tissue in order to identify immunosuppressive factors that were overexpressed in ACP. Cyst fluid and cells contained therein were analyzed using multiplex cytokine analysis and flow cytometry, respectively. A large transcriptomic database of ACP and other pediatric tumors and normal brain was queried for immunosuppressive gene expression. Immunohistochemistry was used to further validate gene expression data. RESULTS: ACP demonstrated highly elevated levels of IDO-1 (FC 9.43 versus all other tumor/tissue types, p=1.4x10-28), confirmed by IHC staining for IDO-1 in the epithelial tumor compartment. Elevated levels of IL-10 were demonstrated in cyst fluid and solid tumor compartments. Myeloid cells from the ACP cyst compartment demonstrated low levels of CD64 and HLA-DR expression, combined with high levels of CD163 expression. This pattern is most consistent with an immunosuppressive, pro-tumor milieu. Both CD4 and CD8(+) T-cells demonstrated positive staining for PD-1, most consistent with an exhausted phenotype. Consistent with this, PD-L1 mRNA was elevated in ACP tumor samples versus many other tumor types. CONCLUSIONS: Pediatric ACP is characterized by immunosuppressive factors in both the solid and cyst fluid compartments. This finding must be further considered within the context of the pro-inflammatory characteristics that have been previously described. It further raises the prospect of clinical translation through the application of available immune-directed therapies, in particular those that elicit therapeutic benefit through reversal of immunosuppression.

OBJECT Operations on tumors of the posteromedial temporal (PMT) region, that is, on those arising from the posterior parahippocampal, fusiform, and lingual gyri, are challenging to perform because of the deep-seated location of these tumors between critical cisternal neurovascular structures and the adjacent temporal and occipital cortexes. Traditional surgical approaches require temporal or occipital transgression, retraction, or venous sacrifice. These approaches may result in unintended complications that should be avoided. To avoid these complications, the supracerebellar-transtentorial (SCTT) approach to this region has been used as an effective alternative treatment in adult patients. The SCTT approach uses a sitting position that offers a direct route to the posterior fusiform and lingual gyri of the temporal lobe. The authors report the feasibility, safety, and efficacy of this approach, using a modified lateral park-bench position in a small cohort of pediatric patients. METHODS The authors carried out a retrospective case review of 5 consecutive patients undergoing a paramedian SCTT approach between 2009 and 2014 at the authors' institution. RESULTS The SCTT approach in the park-bench position was used in 3 boys and 2 girls with a mean age of 7.8 years (range 13 months to 16 years). All patients presented with a seizure disorder related to a tumor in a PMT region involving the parahippocampal and fusiform gyri of the left (n = 3) or right (n = 2) temporal lobe. No procedure-related complications were observed. Gross-total resection and control of seizures were achieved in all cases. Tumor classes and types included 1 Grade II astrocytoma, 1 pleomorphic xanthoastrocytoma, 1 ganglioglioma, and 2 glioneural tumors. None of the tumors had recurred by the mean follow-up of 22 months (range 1–48 months). Outcomes of epileptic seizures were excellent, with seizure symptoms in all 5 patients scoring in Engel Class IA. CONCLUSIONS The SCTT approach represents a viable option when resecting tumors in this region, providing a reasonable working corridor and low morbidity. The authors' experience in a cohort of pediatric patients demonstrates that complete resection of the lesions in this location is feasible and is safe when involving an approach that involves using a park-bench lateral positioning.

Synovial cysts are uncommon pathological entities in patients with cervical degenerative spinal disease, and there are only a few reports in the literature. Treatment typically involves decompression; however, biomechanical data indicate that laminectomies in the cervical spine also result in cervical instability, specifically within the cervicothoracic junction, supporting the use of fusion as well. The authors describe the use of fusion with decompression in the treatment of 3 patients with cervicothoracic synovial cysts that presented in an acute fashion with associated myelopathy and neurological decline, and they review the diagnostic elements, histopathology, and treatment of these cysts. All 3 of the patients did well with decompression via a posterior approach with a single-level instrumented fusion from C-7 to T-1. Each patient regained complete neurological function and had no residual neurological deficits. These results are promising, although the sample size of 3 cases is too small to make any conclusive evaluations. Future studies incorporating Class I and Class II data are imperative to make firm conclusions regarding general management of this rare entity.

Stereotactic radiosurgery to benign tumors of the spine has not been advocated as a primary treatment modality because of the favorable prognosis for these lesions after gross-total resection. There is even less evidence regarding its use as an adjuvant to neurosurgical resection of benign recurrent spinal disease. We describe the case of a 30-year-old man with a thoracic spinal schwannoma who had an interval increase of his lesion five months after thoracoscopic microsurgical resection. The patient opted for noninvasive stereotactic radiosurgery in lieu of additional surgical excision and has had stable disease 15 months after radiosurgical treatment with the linear accelerator (LINAC) system. In this setting, stereotactic radiosurgery provided a useful adjunct to thoracoscopic microsurgical resection. Future Class I and II evidence should be sought to evaluate the utility of stereotactic radiosurgery as a primary treatment modality or as an adjuvant for microneurosurgical resection of benign spinal lesions in patients who want noninvasive treatment after disease recurrence or who harbor medical comorbidities that would preclude them from being safe surgical candidates.

Understanding the genetic alterations that contribute to the development of different disease states is key to the ability to screen and treat patients afflicted with these diseases and may someday enable us to prevent their development. The high degree of morbidity and mortality associated with neurosurgical diseases makes this understanding particularly important. Mechanisms for early diagnosis, followed by appropriate treatment in these patients, could significantly alter the morbidity and mortality rates in patients with neurosurgical diseases. The Utah Population Database (UPDB) is a unique resource that allows population-based analysis of the familial nature of diseases with the identification of high-risk pedigrees and predisposition genes. The UPDB was initially used to study the hereditary element of cancer, but its application is now expanding to include the neurogenomics of neurosurgical diseases. Specifically, the familial and genetic contribution to intracranial aneurysms and nonsyndromic intracranial malignant diseases has been reported in the literature. The UPDB identifies the familial contribution by examining genealogical records that have been linked with clinical, demographic, and diagnostic data compiled in state records. From this information, one can identify possible genetic targets for future therapies.

Cerebral cavernous malformations (CCMs) are common vascular lesions of the CNS that may lead to seizures, focal neurological deficits, and fatal hemorrhagic stroke. Human genetic studies have identified 3 genes associated with CCM, and biochemical and molecular studies in mice have elucidated signaling pathways with important therapeutic implications. In this review, the authors shed light on the 3 discovered CCM genes as well as their protein products, with particular emphasis on their signal transduction pathways and their interaction with one another. Close focus is directed at mice model studies involving the Ccm2 gene product signaling pathway, revealing an important role for the use of simvastatin or other RhoA inhibitors as a therapeutic modality in the treatment of CCM. The remaining challenges to creating a more faithful CCM animal model as well as future clinical and research implications are reviewed.

✓ Halo orthoses are commonly used in the management of a variety of cervical spinal pathological conditions. Although placement of the cranial pins was initially believed to be safe with minimal complications, minor complications related to the cranial pins have the potential to create a setting for formation of cerebral abscesses. The risk of death due to cerebral abscesses has declined in the modern antibiotic era, but cerebral abscesses are associated with long-standing neurological morbidity that should not be considered negligible. Prevention by careful pin placement and hygiene and appropriate early management are crucial to prevent more serious complications. The authors report the case of a patient treated with a halo orthosis after incurring cervical spinal trauma who developed a cerebral abscess as a complication related to the cranial pins of the halo fixation device. They review the literature in an attempt to formulate a standardized treatment algorithm to prevent this disease process and to treat an abscess if it should form.