The Sensitivity of Limited-Sequence MRI in Identifying Pediatric Cervical Spine Injury: A Western Pediatric Surgery Research Consortium Multicenter Retrospective Cohort Study.

INTRODUCTION: Clinical clearance of a child's cervical spine after trauma is often challenging due to impaired mental status or an unreliable neurologic examination. Magnetic resonance imaging (MRI) is the gold standard for excluding ligamentous injury in children but is constrained by long image acquisition times and frequent need for anesthesia. Limited-sequence MRI (LSMRI) is used in evaluating the evolution of traumatic brain injury and may also be useful for cervical spine clearance while potentially avoiding the need for anesthesia. The purpose of this study was to assess the sensitivity and negative predictive value of LSMRI as compared to gold standard full-sequence MRI as a screening tool to rule out clinically significant ligamentous cervical spine injury. METHODS: We conducted a ten-center, five-year retrospective cohort study (2017-2021) of all children (0-18y) with a cervical spine MRI after blunt trauma. MRI images were re-reviewed by a study pediatric radiologist at each site to determine if the presence of an injury could be identified on limited sequences alone. Unstable cervical spine injury was determined by study neurosurgeon review at each site. RESULTS: We identified 2,663 children less than 18 years of age who underwent an MRI of the cervical spine with 1,008 injuries detected on full-sequence studies. The sensitivity and negative predictive value of LSMRI were both >99% for detecting any injury and 100% for detecting any unstable injury. Young children (age < 5 years) were more likely to be electively intubated or sedated for cervical spine MRI. CONCLUSION: LSMRI is reliably detects clinically significant ligamentous injury in children after blunt trauma. To decrease anesthesia use and minimize MRI time, trauma centers should develop LSMRI screening protocols for children without a reliable neurologic exam. LEVEL OF EVIDENCE: 2 (Diagnostic Tests or Criteria).

Pediatric neuromodulation for drug-resistant epilepsy: Survey of current practices, techniques, and outcomes across US epilepsy centers.

Neuromodulation via Responsive Neurostimulation (RNS) or Deep Brain Stimulation (DBS) is an emerging treatment strategy for pediatric drug-resistant epilepsy (DRE). Knowledge gaps exist in patient selection, surgical technique, and perioperative care. Here, we use an expert survey to clarify practices. Thirty-two members of the Pediatric Epilepsy Research Consortium were surveyed using REDCap. Respondents were from 17 pediatric epilepsy centers (missing data in one): Four centers implant RNS only while 13 implant both RNS and DBS. Thirteen RNS programs commenced in or before 2020, and 10 of 12 DBS programs began thereafter. The busiest six centers implant 6-10 new RNS devices per year; all DBS programs implant <5 annually. The youngest RNS patient was 3 years old. Most centers (11/12) utilize MP2RAGE and/or FGATIR sequences for planning. Centromedian thalamic nuclei were the unanimous target for Lennox-Gastaut syndrome. Surgeon exposure to neuromodulation occurred mostly in clinical practice (14/17). Clinically significant hemorrhage (n = 2) or infection (n = 3) were rare. Meaningful seizure reduction (>50%) was reported by 81% (13/16) of centers. RNS and DBS are rapidly evolving treatment modalities for safe and effective treatment of pediatric DRE. There is increasing interest in multicenter collaboration to gain knowledge and facilitate dialogue. PLAIN LANGUAGE SUMMARY: We surveyed 32 pediatric epilepsy centers in USA to highlight current practices of intracranial neuromodulation. Of the 17 that replied, we found that most centers are implanting thalamic targets in pediatric drug-resistant epilepsy using the RNS device. DBS device is starting to be used in pediatric epilepsy, especially after 2020. Different strategies for target identification are enumerated. This study serves as a starting point for future collaborative research.

A multi-center comparison of surgical techniques for corpus Callosotomy in pediatric drug-resistant epilepsy.

OBJECTIVES: Corpus callosotomy (CC) is used to reduce seizures, primarily in patients with generalized drug-resistant epilepsy (DRE). The invasive nature of the procedure contributes to underutilization despite its potential superiority to other palliative procedures. The goal of this study was to use a multi-institutional epilepsy surgery database to characterize the use of CC across participating centers. METHODS: Data were acquired from the Pediatric Epilepsy Research Consortium (PERC) Surgery Database, a prospective observational study collecting data on children 0-18 years referred for surgical evaluation of DRE across 22 U.S. pediatric epilepsy centers. Patient, epilepsy, and surgical characteristics were collected across multiple CC modalities. Outcomes and complications were recorded and analyzed statistically. RESULTS: Eighty-three patients undergoing 85 CC procedures at 14 participating epilepsy centers met inclusion criteria. Mean age at seizure onset was 2.3 years (0-9.4); mean age for Phase I evaluation and surgical intervention were 9.45 (.1-20) and 10.46 (.2-20.6) years, respectively. Generalized seizure types were the most common (59%). Complete CC was performed in 88%. The majority of CC procedures (57%) were via open craniotomy, followed by laser interstitial thermal therapy (LiTT) (20%) and mini-craniotomy/endoscopic (mc/e) (22%). Mean operative times were significantly longer for LiTT, whereas mean estimated blood loss was greater in open cases. Complications occurred in 11 cases (13%) and differed significantly between surgical techniques (p < .001). There was no statistically significant difference in length of postoperative stay across approaches. Mean follow-up was 12.8 months (range 1-39). Favorable Engel outcomes were experienced by 37 (78.7%) of the patients who underwent craniotomy, 10 (58.8%) with LiTT, and 12 (63.2%) with mc/e; these differences were not statistically significant. SIGNIFICANCE: CC is an effective surgical modality for children with DRE. Regardless of surgical modality, complication rates are acceptable and seizure outcomes generally favorable. Newer, less-invasive, surgical approaches may lead to increased adoption of this efficacious therapeutic option for pediatric DRE.

Pediatric neuroblastoma with intraspinal extension: the role of surgical management.

OBJECTIVE: Neuroblastoma with spinal involvement accounts for up to 30% of pediatric spinal tumors and can cause profound neurological deficits. Chemotherapy is the preferred treatment option, but in select patients resection may be indicated. The goal of this study was to identify preoperative factors that led to early surgical intervention, with a specific emphasis on identifying differences on long-term neurological function and spinal deformity in the recent treatment era. METHODS: A retrospective chart review was performed on all children diagnosed with neuroblastoma at a single institution from 2007 to 2020. Patient demographics, symptoms (motor deficit and sphincter dysfunction), and tumor characteristics (e.g., 123I metaiodobenzylguanidine [MIBG] avidity, MYCN amplification, chromosomal abnormality, pathology, catecholamine secretion, and stage) were recorded. Spine involvement included neural or vertebral extension, spinal cord compression, and/or T2 signal change on MRI. Survival, neurological status (motor deficit, sphincter dysfunction), and spine deformity at last follow-up were compared using univariate and multivariate analyses. The variables that contributed to neurological and deformity outcome were assessed with binomial logistic and linear regression models using R software. RESULTS: Seventy-seven of the 160 patients with neuroblastoma had spinal neuroblastoma, meaning either bone metastases alone (n = 43) or intraspinal extension with or without neurological deficit (n= 34). Most patients with spinal neuroblastoma were treated with chemotherapy and/or radiation therapy (97% and 57%, respectively). Resection of the spinal tumor was performed in 14 (18%) patients, all of whom also received chemotherapy. Between the surgical and nonsurgical patients, no baseline demographic differences were found. However, surgical patients were more likely to present with either motor deficits (50% vs 5%, p = 0.0011) or bladder/bowel dysfunction (14% vs 0%, p 0.035), and a shorter median time to onset of neurological symptoms (33 vs 80 days, p = 0.0096). Surgical patients also had a significantly shorter median overall survival (33.0 vs 54 months, p = 0.014). Of the 14 patients who underwent spine surgery, 2 patients underwent surgery at the time of diagnosis while the remaining 12 underwent initial chemotherapy followed later by resection. The 2 patients who underwent initial surgery had excellent outcomes, with neither long-term motor or bowel/bladder deficits nor spinal deformity. CONCLUSIONS: Surgical patients had shorter overall survival. However, the 2 patients with radiographic evidence of cord compression and acute neurological symptom onset who underwent initial, immediate surgery within 3 days of diagnosis had fewer long-term neurological deficits than surgical patients who underwent initial trials of chemotherapy. Thus, acute decompression may provide benefit in carefully selected patients with acute neurological deficits and cord compression on imaging.

Responsive Neurostimulation in Drug-Resistant Pediatric Epilepsy: Findings From the Epilepsy Surgery Subgroup of the Pediatric Epilepsy Research Consortium.

BACKGROUND: Responsive neurostimulation (RNS), a closed-loop intracranial electrical stimulation system, is a palliative surgical option for patients with drug-resistant epilepsy (DRE). RNS is approved by the US Food and Drug Administration for patients aged ≥18 years with pharmacoresistant partial seizures. The published experience of RNS in children is limited. METHODS: This is a combined prospective and retrospective study of patients aged ≤18 years undergoing RNS placement. Patients were identified from the multicenter Pediatric Epilepsy Research Consortium Surgery Registry from January 2018 to December 2021, and additional data relevant to this study were retrospectively collected and analyzed. RESULTS: Fifty-six patients received RNS during the study period. The mean age at implantation was 14.9 years; the mean duration of epilepsy, 8.1 years; and the mean number of previously trialed antiseizure medications, 4.2. Five patients (9%) previously trialed dietary therapy, and 19 patients (34%) underwent prior surgery. Most patients (70%) underwent invasive electroencephalography evaluation before RNS implantation. Complications occurred in three patients (5.3%) including malpositioned leads or transient weakness. Follow-up (mean 11.7 months) was available for 55 patients (one lost), and four were seizure-free with RNS off. Outcome analysis of stimulation efficacy was available for 51 patients: 33 patients (65%) were responders (≥50% reduction in seizure frequency), including five patients (10%) who were seizure free at follow-up. CONCLUSIONS: For young patients with focal DRE who are not candidates for surgical resection, neuromodulation should be considered. Although RNS is off-label for patients aged <18 years, this multicenter study suggests that it is a safe and effective palliative option for children with focal DRE.

Clarifying the clinical landscape of pediatric spinal arteriovenous shunts: an institutional experience and individual patient-data meta-analysis.

BACKGROUND: Pediatric spinal arteriovenous shunts (SAVS) are rare lesions with heterogeneous pathogenesis and clinical manifestations. OBJECTIVE: To evaluate the clinical characteristics, angioarchitecture, and technical/clinical outcomes in SAVS through a large single-center cohort analysis and meta-analysis of individual patient data. METHODS: A retrospective institutional database identified children (aged 0-21 years) who underwent digital subtraction spinal angiography (DSA) for SAVS between January 1996 and July 2021. Clinical data were recorded to evaluate angioarchitecture, generate modified Aminoff-Logue gait disturbance scores (AL) and McCormick grades (MC), and assess outcomes. We then performed a systematic literature review following PRISMA-IPD (Preferred Reporting Items for Systematic Reviews and Meta-Analyses for individual patient data) guidelines, extracting similar data on individual patients for meta-analysis. RESULTS: The cohort consisted of 28 children (M:F=11:17) with 32 SAVS lesions, with a mean age of 12.8±1.1 years at diagnosis. At presentation, SAVS were most highly concentrated in the cervical region (40.6%). Children had a median AL=2 and MC=2, with thoracolumbar AVS carrying the greatest disability. Among treated cases, complete obliteration was achieved in 48% of cases and median AL scores and MC grades both improved by one point. Systematic literature review identified 161 children (M:F=96:65) with 166 SAVS lesions with a mean age of 8.7±0.4 years. Among studies describing symptom chronicity, 37/51 (72.5%) of children presented acutely. At presentation, children had a median AL=4 and MC=3, with thoracolumbar AVS carrying the highest MC grades. After intervention, median AL and MC both improved by one point. CONCLUSIONS: This study provides epidemiologic information on the location, onset, and presentation of the full spectrum of pediatric SAVS, highlighting the role of targeted treatment of high-risk features.

A comparison of incidental and symptomatic unruptured brain arteriovenous malformations in children.

OBJECTIVE: Patients with unruptured brain arteriovenous malformations (AVMs) may present with headaches, seizures, and/or neurological deficits. A smaller number of cases may be discovered incidentally. These lesions remain incompletely understood due to their sparse reporting. Herein, the authors describe the largest series to date comparing the presentation, angioarchitecture, and management of incidental versus symptomatic unruptured AVMs in children. METHODS: The authors performed a retrospective analysis of patients who presented with brain AVMs from 1998 to 2022 at the University of California, San Francisco. Inclusion criteria were age ≤ 18 years at the time of presentation and an angiographically proven unruptured AVM that had been diagnosed postnatally. RESULTS: Of 76 children with unruptured AVMs, 66 (86.8%) presented with headaches, seizures, and/or neurological deficit. Ten AVMs (13.1%) were incidentally discovered through unrelated disease workup (50%), cranial trauma (40%), or research study participation (10%). Compared with patients with symptomatic unruptured AVMs, patients with incidental unruptured AVMs had a smaller mean ± SD maximum nidus diameter (2.82 ± 1.1 vs 3.98 ± 1.52 cm, p = 0.025) and fewer had deep venous drainage (20% of patients vs 61%, p = 0.036). They also presented at an earlier age (10 ± 5.2 vs 13.5 ± 4 years, p = 0.043) and with longer duration to first treatment (541 ± 922 vs 196 ± 448 days, p = 0.005). During the observation period, 1 patient developed recurring headaches and demonstrated AVM nidus growth. Four AVMs greater than 3 cm in size or in a deep location were treated with radiosurgery. Six other AVMs were treated with resection, with 2 receiving preoperative embolization. Eight AVMs (80%) were obliterated on last follow-up. Postprocedural complications included 2 transient neurological deficits after resection and 1 case of delayed seizure development after radiosurgery. The mean follow-up period was 5.7 ± 5.7 years without any hemorrhage episodes. CONCLUSIONS: A substantial proportion of pediatric patients with unruptured AVMs are discovered incidentally. With earlier presentation and more elementary angioarchitecture than symptomatic unruptured AVMs, these incidental lesions provide a snapshot into the natural history of AVM before symptom development or rupture.

Epilepsy surgery in children with genetic etiologies: A prospective evaluation of current practices and outcomes.

OBJECTIVE: This study assesses current practices and outcomes of epilepsy surgery in children with a genetic etiology. It explores the pre-surgical workup, types of surgeries, and post-surgical outcomes in a broad array of disorders. METHODS: Patients ≤18 years who completed epilepsy surgery and had a known genetic etiology prior to surgical intervention were extrapolated from the Pediatric Epilepsy Research Consortium (PERC) surgery database, across 18 US centers. Data were assessed univariably by neuroimaging and EEG results, genetic group (structural gene, other gene, chromosomal), and curative intent. Outcomes were based on a modified International League Against Epilepsy (ILAE) outcome score. RESULTS: Of 81 children with genetic epilepsy, 72 % had daily seizures when referred for surgery evaluation, which occurred a median of 2.2 years (IQR 0.3, 5.2) after developing drug resistance. Following surgery, 68 % of subjects had >50 % seizure reduction, with 33 % achieving seizure freedom [median follow-up 11 months (IQR 6, 17). Seizure freedom was most common in the monogenic structural group, but significant palliation was present across all groups. Presence of a single EEG focus was associated with a greater likelihood of seizure freedom (p=0.02). SIGNIFICANCE: There are meaningful seizure reductions following epilepsy surgery in the majority of children with a genetic etiology, even in the absence of a single structural lesion and across a broad spectrum of genetic causes. These findings highlight the need for expedited referral for epilepsy surgery and support of a broadened view of which children may benefit from epilepsy surgery, even when the intent is palliative.

TRAF7 somatic mosaicism in a patient with bilateral optic nerve sheath meningiomas: illustrative case.

BACKGROUND: In the past decade, next-generation sequencing has spurred significant progress in the understanding of cytogenetic alterations that occur in meningiomas. Eighty percent of adult meningiomas harbor pathogenic somatic variants involving NF2, TRAF7, SMARCB1, KLF4, PI3K, or POLR2A. Somatic variants in TRAF7 associated with meningiomas usually localize to the gene's WD40 domains but are mutually exclusive to germline mutations, which cause a distinctive autosomal dominant syndrome. OBSERVATIONS: This case involved a 15-year-old girl with bilateral optic nerve sheath meningiomas, diffuse meningiomatosis, and syndromic features, including craniosynostosis, brain anomalies, syndactyly, brachydactyly, epicanthus, and patent ductus arteriosus. Genetic testing of the meningioma specimen 7 years after biopsy showed a pathogenic p.R641C variant within the WD40 domain of the TRAF7 gene. Additional testing of unaffected tissues identified the same variant at lower allele frequencies, consistent with postzygotic somatic mosaicism. LESSONS: The authors report postzygotic somatic mosaicism for a p.R641C variant in the TRAF7 gene in a patient with bilateral optic nerve sheath meningiomas, diffuse meningiomatosis and a constellation of systemic findings previously recognized in patients with germline mutations of this gene. This is the first report of optic nerve sheath meningioma in a patient with mutation in the TRAF7 gene.

The Hybrid Operative Suite with Intraoperative Biplane Rotational Angiography in Pediatric Cerebrovascular Neurosurgery: Utility and Lessons Learned.

INTRODUCTION: The benefits of performing open and endovascular procedures in a hybrid neuroangiography surgical suite include confirmation of treatment results and reduction in number of procedures, leading to improved efficiency of care. Combined procedural suites are infrequently used in pediatric facilities due to technical and logistical limitations. We report the safety, utility, and lessons learned from a single-institution experience using a hybrid suite equipped with biplane rotational digital subtraction angiography and pan-surgical capabilities. METHODS: We conducted a retrospective review of consecutive cases performed at our institution that utilized the hybrid neuroangiography surgical suite from February 2020 to August 2021. Demographics, surgical metrics, and imaging results were collected from the electronic medical record. Outcomes, interventions, and nuances for optimizing preoperative/intraoperative setup and postoperative care were presented. RESULTS: Eighteen procedures were performed in 17 patients (mean age 13.4 years, range 6-19). Cases included 14 arteriovenous malformations (AVM; 85.7% ruptured), one dural arteriovenous fistula, one mycotic aneurysm, and one hemangioblastoma. The average operative time was 416 min (range 321-745). There were no intraoperative or postoperative complications. All patients were alive at follow-up (range 0.1-14.7 months). Five patients had anticipated postoperative deficits arising from their hemorrhage, and 12 returned to baseline neurological status. Four illustrative cases demonstrating specific, unique applications of the hybrid angiography suite are presented. CONCLUSION: The hybrid neuroangiography surgical suite is a safe option for pediatric cerebrovascular pathologies requiring combined surgical and endovascular intervention. Hybrid cases can be completed within the same anesthesia session and reduce the need for return to the operating room for resection or surveillance angiography. High-quality intraoperative angiography enables diagnostic confirmation under a single procedure, mitigating risk of morbidity and accelerating recovery. Effective multidisciplinary planning enables preoperative angiograms to be completed to inform the operative plan immediately prior to definitive resection.

Superior Long-term Appearance of Strip Craniectomy Compared with Cranial Vault Reconstruction in Metopic Craniosynostosis.

BACKGROUND: Strip craniectomy with orthotic helmet therapy (SCOT) is an increasingly supported treatment for metopic craniosynostosis, although the long-term efficacy of deformity correction remains poorly defined. We compared the longterm outcomes of SCOT versus open cranial vault reconstruction (OCVR). METHODS: Patients who underwent OCVR or SCOT for isolated metopic synostosis with at least 3 years of follow-up were identified at our institution. Anthropometric measurements were used to assess baseline severity and postoperative skull morphology. Independent laypersons and craniofacial surgeons rated the appearance of each patient's 3D photographs, compared to normal controls. RESULTS: Thirty-five patients were included (15 SCOT and 20 OCVR), with similar follow-up between groups (SCOT 7.9 ± 3.2 years, OCVR 9.2 ± 4.1 years). Baseline severity and postoperative anthropometric measurements were equivalent. Independent adolescent raters reported that the forehead, eye, and overall appearance of SCOT patients was better than OCVR patients (P < 0.05, all comparisons). Craniofacial surgeons assigned Whitaker class I to a greater proportion of SCOT patients with moderate-to-severe synostosis (72.2 ± 5.6%) compared with OCVR patients with the same severity (33.3 ± 9.2%, P = 0.02). Parents of children who underwent SCOT reported equivalent satisfaction with the results of surgery (100% versus 95%, P > 0.99), and were no more likely to report bullying (7% versus 15%, P = 0.82). CONCLUSIONS: SCOT was associated with superior long-term appearance and perioperative outcomes compared with OCVR. These findings suggest that SCOT should be the treatment of choice for patients with a timely diagnosis of metopic craniosynostosis.

Repetitive transcranial magnetic stimulation (rTMS) as therapy in an infant with epilepsia partialis continua.

Introduction: We present a case of a 10-month-old girl undergoing repetitive TMS (rTMS) for the treatment of drug-resistant epilepsy. Case report: A 10-month-old girl, later diagnosed with pathogenic POLG1 mutations, presented to our institution with chronic progressive EPC (epilepsia partialis continua) manifesting as a frequent, left-sided, synchronous continuous jerking of the arms and legs. The seizures were drug-resistant to multiple antiseizure medications and epilepsy surgery, responding only to continuous anesthesia. rTMS therapy was attempted to interrupt seizures. Results: rTMS therapy, using an activating protocol to introduce a temporary lesion effect, was used to interrupt persistent, ongoing seizures. Conclusion: rTMS can be safely used to abort seizures in patients as young as 10 months old.

Navigated transcranial magnetic stimulation mapping of the motor cortex for preoperative diagnostics in pediatric epilepsy.

OBJECTIVE: Navigated transcranial magnetic stimulation (nTMS) is a noninvasive technique often used for localization of the functional motor cortex via induction of motor evoked potentials (MEPs) in neurosurgical patients. There has, however, been no published record of its application in pediatric epilepsy surgery. In this study, the authors aimed to investigate the feasibility of nTMS-based motor mapping in the preoperative diagnostic workup within a population of children with medically refractory epilepsy. METHODS: A single-institution database was screened for preoperative nTMS motor mappings obtained in pediatric patients (aged 0 to 18 years, 2012 to present) with medically refractory epilepsy. Patient clinical data, demographic information, and mapping results were extracted and used in statistical analyses. RESULTS: Sixteen patients met the inclusion criteria, 15 of whom underwent resection. The median age was 9 years (range 0-17 years). No adverse effects were recorded during mapping. Specifically, no epileptic seizures were provoked via nTMS. Recordings of valid MEPs induced by nTMS were obtained in 10 patients. In the remaining patients, no MEPs could be elicited. Failure to generate MEPs was associated significantly with younger patient age (r = 0.8020, p = 0.0001863). The most frequent seizure control outcome was Engel Epilepsy Surgery Outcome Scale class I (9 patients). CONCLUSIONS: Navigated TMS is a feasible, effective, and well-tolerated method for mapping the motor cortex of the upper and lower extremities in pediatric patients with epilepsy. Patient age modulates elicitability of MEPs, potentially reflecting various stages of myelination. Successful motor mapping has the potential to add to the existing presurgical diagnostic workup in this population, and further research is warranted.

Impact of the Skull Size on the Normal Brain Radiation Dose During Gamma Knife Radiosurgery: Results of a Pilot Study.

OBJECTIVE: The objective of the present study was evaluation of the interrelationships between changes in the skull size and variations in the normal brain radiation dose during Gamma Knife surgery (GKS). METHODS: With use of systematic modeling within Leksell GammaPlan® (Elekta AB; Stockholm, Sweden) in each of 15 analyzed cases, the skull was "expanded" and "contracted" by variation of its measurement values from 0 to ±3 cm. The mean normal brain radiation dose was then computed for each variant of the adjusted skull size and compared with the original treatment plan. Variations in the maximum point dose delivered to selected critical anatomical structures were also investigated. RESULTS: With changes in the skull radius within ±3 cm, the maximum absolute deviation in the mean normal brain radiation dose was 0.8%. As the skull radius increased, the mean normal brain radiation dose also increased linearly (confidence level >99%) with a positive slope of 0.2% per centimeter of radius length change. The maximum point dose deviations in all evaluated critical anatomical structures did not exceed 0.5%, with an overall trend toward a dose increase in parallel with an increase in the skull radius. CONCLUSION: The small skull size of pediatric patients may be associated with dosimetric advantages in terms of normal brain sparing during GKS.

Direct brain recordings reveal occipital cortex involvement in memory development.

Processing of low-level visual information shows robust developmental gains through childhood and adolescence. However, it is unknown whether low-level visual processing in the occipital cortex supports age-related gains in memory for complex visual stimuli. Here, we examined occipital alpha activity during visual scene encoding in 24 children and adolescents, aged 6.2-20.5 years, who performed a subsequent memory task while undergoing electrocorticographic recording. Scenes were classified as high- or low-complexity by the number of unique object categories depicted. We found that recognition of high-complexity, but not low-complexity, scenes increased with age. Age was associated with decreased alpha power and increased instantaneous alpha frequency during the encoding of subsequently recognized high- compared to low-complexity scenes. Critically, decreased alpha power predicted improved recognition of high-complexity scenes in adolescents. These findings demonstrate how the functional maturation of the occipital cortex supports the development of memory for complex visual scenes.

Comprehensive analysis of diverse low-grade neuroepithelial tumors with FGFR1 alterations reveals a distinct molecular signature of rosette-forming glioneuronal tumor.

The FGFR1 gene encoding fibroblast growth factor receptor 1 has emerged as a frequently altered oncogene in the pathogenesis of multiple low-grade neuroepithelial tumor (LGNET) subtypes including pilocytic astrocytoma, dysembryoplastic neuroepithelial tumor (DNT), rosette-forming glioneuronal tumor (RGNT), and extraventricular neurocytoma (EVN). These activating FGFR1 alterations in LGNET can include tandem duplication of the exons encoding the intracellular tyrosine kinase domain, in-frame gene fusions most often with TACC1 as the partner, or hotspot missense mutations within the tyrosine kinase domain (either at p.N546 or p.K656). However, the specificity of these different FGFR1 events for the various LGNET subtypes and accompanying genetic alterations are not well defined. Here we performed comprehensive genomic and epigenomic characterization on a diverse cohort of 30 LGNET with FGFR1 alterations. We identified that RGNT harbors a distinct epigenetic signature compared to other LGNET with FGFR1 alterations, and is uniquely characterized by FGFR1 kinase domain hotspot missense mutations in combination with either PIK3CA or PIK3R1 mutation, often with accompanying NF1 or PTPN11 mutation. In contrast, EVN harbors its own distinct epigenetic signature and is characterized by FGFR1-TACC1 fusion as the solitary pathogenic alteration. Additionally, DNT and pilocytic astrocytoma are characterized by either kinase domain tandem duplication or hotspot missense mutations, occasionally with accompanying NF1 or PTPN11 mutation, but lacking the accompanying PIK3CA or PIK3R1 mutation that characterizes RGNT. The glial component of LGNET with FGFR1 alterations typically has a predominantly oligodendroglial morphology, and many of the pilocytic astrocytomas with FGFR1 alterations lack the biphasic pattern, piloid processes, and Rosenthal fibers that characterize pilocytic astrocytomas with BRAF mutation or fusion. Together, this analysis improves the classification and histopathologic stratification of LGNET with FGFR1 alterations.

Extradural thoracic meningeal cyst without spinal dysraphism causing adulthood myelopathy: Case illustration and review of the literature.

Extradural spinal meningeal cysts are rare lesions in the adult spine and are an uncommon cause of neurologic deficits. We present the case of an adult who presented with myelopathic symptoms related to a dorsally based extradural thoracic meningeal cyst in the absence of any defect in the posterior spinal elements and no history of spinal dysraphism or trauma. We also performed a review of the literature to evaluate the surgical techniques for extradural meningeal cysts. Most thoracic cysts are intradural arachnoid cysts, yet this lesion is an extradural meningeal cyst, not an intradural arachnoid cyst. Because of the rarity of this lesion, its anatomic characterization can be difficult to conceptualize. An artist's illustration helps illustrate the anatomic characteristics of this cyst and our surgical management.

Single-center series of boys with recurrent strokes and rotational vertebral arteriopathy.

OBJECTIVE: To describe a pediatric stroke syndrome with chronic focal vertebral arteriopathy adjacent to cervical abnormalities. METHODS: At a single pediatric stroke center, we identified consecutive children with stroke and vertebral arteriopathy of the V3 segment with adjacent cervical bony or soft tissue abnormalities. We abstracted clinical presentation, treatment, and follow-up data from medical charts. RESULTS: From 2005 to 2019, 10 children (all boys, ages 6-16 years) presented with posterior circulation strokes and vertebral arteriopathy with adjacent cervical pathology. Two children had bony abnormalities: one had a congenital arcuate foramen and one had os odontoideum with cervical instability. In children without bony pathology, vertebral artery narrowing during contralateral head rotation was visualized by digital subtraction angiography. Eight boys had recurrent ischemic events despite anti-thrombotic treatment (including 5 with multiple recurrences) and were treated surgically to prevent additional stroke. Procedures included vertebral artery decompression (n = 6), endovascular stent and spinal fusion (n = 1), and vertebral artery endovascular occlusion (n = 1). In boys treated with decompression, cervical soft tissue abnormalities (ruptured atlantoaxial bursa, ruptured joint capsule, or connective tissue scarring) were directly visualized during open surgery. No other etiology for stroke or dissection was found in any of the cases. Two boys without recurrent stroke were treated with activity restriction and antithrombotics. At a median follow-up of 51 months (range 17-84), there have been no additional recurrences. CONCLUSIONS: Children with V3 segmental vertebral arteriopathy frequently have stroke recurrence despite antithrombotics. Cervical bone imaging and angiography with neck rotation can identify underlying pathology.

Meningiomas in children.

Meningiomas in children are poorly understood because they are rare. Recent reports have provided a more complete description of their incidence, genetics, imaging features, and outcome. In general, meningiomas in children are more likely to be higher grade, present in atypical locations, and have a higher risk of recurrence. The challenges encountered in children with respect to surgical and postoperative management are unique. Improved understanding of pediatric meningiomas, as well as the availability of new surgical, medical, and radiation therapies, creates opportunities to improve outcomes in this unique population.