Postoperative seizures following endoscopic third ventriculostomy and choroid plexus cauterization: a case series.

OBJECTIVE: In this study, the authors sought to investigate variables associated with postoperative seizures following endoscopic third ventriculostomy and choroid plexus cauterization (ETV/CPC) for treatment of pediatric hydrocephalus. METHODS: A retrospective analysis of 37 patients who underwent ETV/CPC for treatment of hydrocephalus at an academic medical center from September 2016 to March 2021 was conducted. Demographics, etiology of hydrocephalus, operative details, electroencephalography (EEG) data, MRI findings, need for subsequent procedures, perioperative laboratory tests, medical history, and presence of clinical postoperative seizures were collected. Postoperative seizures were defined as clinical seizures within 24 hours of surgery. Eighteen patients received levetiracetam intraoperatively as well as over the next 7 days postoperatively for seizure prophylaxis. RESULTS: Of 37 included patients, 9 (24%) developed clinical seizures within 24 hours after surgery, 5 of whom subsequently had electroclinical seizures captured on video-EEG. The clinical seizures in 4 of those 5 patients (80%) may have been associated with the hemisphere of the brain through which the endoscope was introduced. The median corrected age of the cohort was 3.4 months. The median corrected age of patients who did not develop postoperative seizures was 2.3 months compared with 0.7 months for patients who did develop postoperative seizures (p > 0.99). Postoperative seizures occurred in 43% (3/7) of prenatally repaired myelomeningocele patients versus 29% (2/7) of postnatally repaired myelomeningocele patients. Of the 18 patients who received prophylactic levetiracetam, none (0%) developed postoperative seizures compared with 9 of the 19 patients (47%) who did not receive prophylactic levetiracetam (p = 0.014). CONCLUSIONS: Postoperative seizures were recorded in 24% of the pediatric patients who underwent ETV/CPC for hydrocephalus, which is higher than previously reported rates in the literature of 5%. Since 80% of the postoperative electrographic seizures may have been associated with the hemisphere through which the endoscope was introduced, the surgical entry site may contribute to postoperative seizure development. In patients who received prophylactic perioperative levetiracetam, the postoperative seizure incidence dropped to 0% compared with 47% in those who did not receive prophylactic perioperative levetiracetam. This finding indicates that the use of prophylactic perioperative levetiracetam may be efficacious in the prevention of clinical seizures in this patient population.

Pediatric Neurosurgery in Primary Care: Masses of the Scalp and Skull in Children.

There are a wide variety of scalp and skull lesions that can affect the pediatric population, many of which are first encountered by primary care physicians. The differential consists of a broad range of more common congenital lesions, sequelae of trauma, and vascular anomalies, to very rare neoplastic processes. It is important to understand signs and symptoms that may indicate whether a lesion may be benign versus life threatening, what imaging studies are appropriate and how to interpret them, and when to seek referrals to specialists.

Long-term Efficacy of Single-agent Vemurafenib for Pleomorphic Xanthoastrocytoma.

Pleomorphic xanthoastrocytoma is a malignant brain tumor that has a good prognosis with complete resection but does not respond well to chemotherapy if there is residual tumor. BRAF V600E mutations are common in pleomorphic xanthoastrocytomas and provide an additional means for treatment when excision is not possible. Monotherapy with the BRAF V600E inhibitor vemurafenib has only been reported in a small number of cases and mostly in adults. We present the case of a 16-year-old male who responded to vemurafenib monotherapy initially and had an additional response to vemurafenib following progression after a brief time off the medication.

Neonatal Hydrocephalus Treatment with Ultrasmall Valve Implantation.

OBJECTIVE: Neonatal hydrocephalus remains a difficult condition to manage, due to high failure rates among all management strategies. Neurosurgeons commonly manage hydrocephalus with ventriculoperitoneal shunt (VPS) implantation, and valves of variable sizes and profiles are available for implantation. This study examines primary ventricular shunt valve implantation complication rates based on valve profiles in pediatric patients with hydrocephalus. METHODS: This study retrospectively reviews pediatric patients younger than 1 year of age who underwent ventricular shunt placement at a single institution from January 2001 to January 2017. Patients were classified by valve profile and categorized as either ultrasmall valves or regular-sized valves. Time until complication and type of complication were studied. RESULTS: A total of 156 patients met the inclusion criteria. Forty-eight (31%) patients received an ultrasmall shunt valve, while 108 patients received a regular valve. On average, patients undergoing ultrasmall valve placement were younger (2.1 months) than patients undergoing placement of regular valves (3.1 months) (P = 0.03). The overall complication rate within 2 years of VPS placement was 37.5% in patients with the ultrasmall valve and 41.7% in the regular valve population. There was no difference in 1-year shunt survival rate between the 2 cohorts. CONCLUSION: Our review did not find a significant difference in complication rates between ultrasmall and regular valves in patients under 1 year of age. However, the etiology of shunt malfunction did differ between the groups. This work further supports evidence suggesting a surgeon's preference for shunt hardware alone does not significantly impact outcome.

Septal dysembryoplastic neuroepithelial tumor: a comprehensive clinical, imaging, histopathologic, and molecular analysis.

BACKGROUND: Dysembryoplastic neuroepithelial tumors (DNETs) are uncommon neural tumors presenting most often in children and young adults and associated with intractable seizures. Rare midline neoplasms with similar histological features to those found in DNETs have been described near the septum pellucidum and termed "DNET-like neoplasms of the septum pellucidum." Due to their rarity, these tumors have been described in just a few reports and their genetic alterations sought only in small series. METHODS: We collected 20 of these tumors for a comprehensive study of their clinical, radiological, and pathological features. RNA sequencing or targeted DNA sequencing was undertaken on 18 tumors, and genome-wide DNA methylation profiling was possible with 11 tumors. Published cases (n = 22) were also reviewed for comparative purposes. RESULTS: The commonest presenting symptoms and signs were related to raised intracranial pressure; 40% of cases required cerebrospinal fluid diversion. Epilepsy was seen in approximately one third of cases. All patients had an indolent disease course, despite metastasis within the neuraxis in a few cases. Radiologically, the septum verum/septal nuclei were involved in all cases and are the proposed site of origin for septal DNET (sDNET). Septal DNET showed a high frequency (~80%) of mutations of platelet derived growth factor receptor A (PDGFRA), and alterations in fibroblast growth factor receptor 1 (FGFR1) and neurofibromatosis type 1 (NF1) were also identified. In a genomic DNA methylation analysis alongside other neural tumors, sDNETs formed a separate molecular group. CONCLUSIONS: Genetic alterations that are different from those of cerebral DNETs and a distinct methylome profile support the proposal that sDNET is a distinct disease entity.

Co-occurrence of frameshift mutations in SMAD6 and TCF12 in a child with complex craniosynostosis.

Non-syndromic craniosynostosis (CS) affects 1 in 2350 live births. Recent studies have shown that a significant fraction of cases are caused by de novo or rare transmitted mutations that promote premature osteoblast differentiation in cranial sutures. Rare heterozygous loss-of-function (LOF) mutations in SMAD6 and TCF12 are highly enriched in patients with non-syndromic sagittal and coronal CS, respectively. Interestingly, both mutations show striking incomplete penetrance, suggesting a role for modifying alleles; in the case of SMAD6, a common variant near BMP2 drastically increases penetrance of sagittal CS. Here, we report a proband presenting with both sagittal and coronal craniosynostosis with the highly unusual recurrence of CS within two months of initial surgery, requiring a second operation to re-establish suture patency at six months of age. Exome sequencing revealed a rare transmitted frameshift mutation in SMAD6 (p. 152 fs*27) inherited from an unaffected parent, absence of the common BMP2 risk variant, and a de novo frameshift mutation in TCF12 (p.E548fs*14). SMAD6 and TCF12 independently inhibit transcriptional targets of BMP signaling. The findings are consistent with epistasis of these mutations, increasing penetrance and severity of CS in this proband. They also add to the list of composite phenotypes resulting from two Mendelian mutations, and support the utility of exome sequencing in atypical CS cases.

Chiari decompression outcomes using ligamentum nuchae harvest and duraplasty in pediatric patients with Chiari malformation type I.

OBJECTIVE The choice of graft material for duraplasty in decompressions of Chiari malformations remains a matter of debate. The authors present a detailed technique for harvesting ligamenta nuchae, as well as the clinical and radiographic outcomes of this technique, in a case series. METHODS The authors conducted a retrospective study evaluating the outcomes of Chiari malformation type I decompression and duraplasty in children aged 0-18 years at a single institution from 2013 to 2016. They collected both intraoperative and postoperative variables and compared them qualitatively to published data. RESULTS During the study period, the authors performed 25 Chiari malformation decompressions with ligamentum nuchae graft duraplasties. Of the 25 patients, 10 were females, and the mean age at surgery was 8.6 years (range 13 months to 18 years). The median operative time was 163 minutes (IQR 152-187 minutes), with approximately 10 minutes needed by a resident surgeon to harvest the graft. The mean length of stay was 3 nights (range 2-6 nights), and the mean follow-up was 12.6 months (range 0.5-43.5 months). One patient (4%) developed a CSF leak that was repaired using an oversewing patch. There were no postoperative pseudomeningoceles or infections. Of the 19 patients presenting with a syrinx, imaging showed improvement in 10 (53%) and 8 (42%) had stable syrinx size on imaging. Of 16 patients presenting with a symptomatic Chiari malformation, 14 (87.5%) experienced resolution of symptoms and in 1 (4%) symptoms remained the same. One patient (4%) presented with worsening syrinx and symptoms 1.5 months after initial surgery and underwent repeat decompression. CONCLUSIONS The authors describe a series of clinical and imaging outcomes of patients who underwent Chiari malformation decompression and duraplasty with a harvested ligamentum nuchae. The rates of postoperative CSF leak are similar to established techniques of autologous and artificial grafts, with similarly successful outcomes. Further study will be needed with larger patient cohorts to more directly compare duraplasty graft outcomes.

Ventriculosubgaleal shunts at Columbus Children's Hospital: Neurosurgical implant placement in the neonatal intensive care unit.

OBJECT: The authors review all cases in which ventriculosubgaleal (VSG) shunts were placed at Columbus Children's Hospital for the treatment of posthemorrhagic hydrocephalus in order to assess the surgical procedure, effectiveness of surgery, and complications of cerebrospinal fluid diversion to the subgaleal space. The purpose of the review is to make a comparison between cases in which shunts were placed in the operating room (OR) and those in which they were placed in the neonatal intensive care unit (NICU). Considerations and complications specific to patient transport to the OR or surgical implantation in the NICU are discussed. METHODS: Seventeen infants with posthemorrhagic hydrocephalus were treated with VSG shunt placement over a period of 4 years. A retrospective analysis of these cases was performed to evaluate multiple aspects of the procedure. Specifically, the surgical procedure, duration of shunt function prior to shunt conversion, neuroimaging changes, operative complications, and risk of infection are discussed. The authors also performed a comparative analysis of shunt placement in the NICU and the OR. RESULTS: The length of the procedure was similar in the two locations. No differences in perioperative or intraoperative risks and no increased risk of infection were seen in either location in this pilot study. Interestingly, the mean lifespan of primary implants placed in the NICU (73 days) was longer than that of those placed in the OR (43 days). CONCLUSIONS: Ventriculosubgaleal shunt placement offers a safe and effective temporary means of treating post-hemorrhagic hydrocephalus and can be reliably and safely performed at the bedside.