SummaryObjective: Glioneuronal tumors (GNTs) are well-recognized causes of chronic drug-resistant focal epilepsy in children. Our practice involves an initial period of radiological surveillance and antiepileptic medications, with surgery being reserved for those with radiological progression or refractory seizures. We planned to analyze the group of patients with low-grade GNTs, aiming to identify factors affecting seizure and cognitive outcomes. Methods: We retrospectively reviewed the medical records of 150 children presenting to Great Ormond Street Hospital with seizures secondary to GNTs. Analysis of clinical, neuroimaging, neuropsychological, and surgical factors was performed to determine predictors of outcome. Seizure outcome at final follow-up was classified as either seizure-free (group A) or not seizure-free (group B) for patients with at least 12-months follow-up postsurgery. Full-scale intelligence quotient (FSIQ) was used as a measure of cognitive outcome. Results: Eighty-six males and 64 females were identified. Median presurgical FSIQ was 81. One hundred twenty-one patients (80.5%) underwent surgery. Median follow-up after surgery was 2 years, with 92 patients (76%) having at least 12 months of follow-up after surgery. Seventy-four patients (80%) were seizurefree, and 18 (20%) continued to have seizures. Radiologically demonstrated complete tumor resection was associated with higher rates of seizure freedom (P = .026). Higher presurgical FSIQ was related to shorter epilepsy duration until surgery (P = .012) and to older age at seizure onset (P = .043). Significance: A high proportion of children who present with epilepsy and GNTs go on to have surgical tumor resection with excellent postoperative seizure control. Complete resection is associated with a higher chance of seizure freedom. Higher presurgical cognitive functioning is associated with shorter duration of epilepsy prior to surgery and with older age at seizure onset. Given the high rate of eventual surgery, early surgical intervention should be considered in children with continuing seizures associated with GNTs.

Aims: To evaluate the predictive value of symptoms, signs, and radiographic findings accompanying presumed ventriculoperitoneal (VP) shunt malfunction, by comparing presentation with operative findings and subsequent clinical course. Methods: Prospective study of all 53 patient referrals to a paediatric neurosurgical centre between April and November 1999 with a diagnosis of presumed shunt malfunction. Referral pattern, presenting symptoms and signs, results of computed tomography (CT) scanning, operative findings, and clinical outcome were recorded. Two patient groups were defined, one with proven shunt block, the other with presumed normal shunt function. Symptomatology, CT scan findings, and the subsequent clinical course for each group were then compared. Results: Common presenting features were headache, drowsiness, and vomiting. CT scans were performed in all patients. Thirty seven had operatively proven shunt malfunction, of whom 34 had shunt block and three shunt infection; 84% with shunt block had increased ventricle size when compared with previous imaging. For the two patient groups (with and without shunt block), odds ratios with 95% confidence intervals on their presenting symptoms were headache 1.5 (0.27 to 10.9), vomiting 0.9 (0.25 to 3.65), drowsiness 10 (0.69 to 10.7), and fever 0.19 (0.03 to 6.95). Every patient with ventricular enlargement greater than their known baseline had a proven blocked shunt. Conclusions: Drowsiness is by far the best clinical predictor of VP shunt block. Headache and vomiting were less predictive of acute shunt block in this study. Wherever possible CT scan findings should be interpreted in the context of previous imaging. We would caution that not all cases of proven shunt blockage present with an increase in ventricle size. C erebrospinal fluid (CSF) shunts remain the mainstay of treatment for most cases of hydrocephalus in the paediatric population. All are prone to malfunction, with block being the commonest reported complication in most series. In the largest reported cohort of 1719 patients, 56% experienced at least one episode of shunt block in the 12 years following insertion.1 Similarly, Lazareff and colleagues 2 recently reported a 44% prevalence of shunt malfunction, including block, in 244 children with CSF shunts followed up over a period of up to six years post initial insertion. The peak "danger" period for blockage is in the first year after insertion, with rates as high as 20% recorded in some series.3 Annual rates of shunt blockage have been estimated by Rekate to be approximately 5%. 4 These findings are in keeping with our published unit experience in which we noted a 28% incidence of shunt block over a 10 year period, and that 55% of patients experienced at least one episode of shunt malfunction during this time.

OBJECTIVE Robot-assisted (RA) stereotactic MRI–guided laser ablation has been reported to be a safe and effective technique for the treatment of epileptogenic foci in children and adults. In this study the authors aimed to assess the accuracy of RA stereotactic MRI–guided laser fiber placement in children and to identify factors that might increase the risk of misplacement. METHODS A retrospective single-institution review of all children from 2019 to 2022 who underwent RA stereotactic MRI–guided laser ablation for epilepsy was undertaken. Placement error was calculated at the target by measuring the Euclidean distance between the implanted laser fiber position and the preoperatively planned position. Collected data included age at surgery, sex, pathology, date of robot calibration, number of catheters, entry position, entry angle, extracranial soft-tissue thickness, bone thickness, and intracranial catheter length. A systematic review of the literature was also performed using Ovid Medline, Ovid Embase, and the Cochrane Central Register of Controlled Trials. RESULTS In 28 children with epilepsy, the authors assessed 35 RA stereotactic MRI–guided laser ablation fiber placements. Twenty (71.4%) children had undergone ablation for hypothalamic hamartoma, 7 children (25.0%) for presumed insular focal cortical dysplasia, and 1 patient (3.6%) for periventricular nodular heterotopia. Nineteen children were male (67.9.%) and 9 were female (32.1%). The median age at the time of the procedure was 7.67 years (IQR 4.58–12.26 years). The median target point localization error (TPLE) was 1.27 mm (IQR 0.76–1.71 mm). The median offset error between the planned and actual trajectories was 1.04° (IQR 0.73°–1.46°). Patient age, sex, pathology and the time interval between date of surgery and robot calibration, entry position, entry angle, soft-tissue thickness, bone thickness, and intracranial length were not associated with the placement accuracy of the implanted laser fibers. However, the number of catheters placed did correlate with the offset angle error on univariate analysis (ρ = 0.387, p = 0.022). There were no immediate surgical complications. Meta-analysis indicated that the overall pooled mean TPLE was 1.46 mm (95% CI −0.58 to 3.49 mm). CONCLUSIONS RA stereotactic MRI–guided laser ablation for epilepsy in children is highly accurate. These data will aid surgical planning.