Faculty Bibliography

Seizures are a common presentation in both emergency departments and general pediatric practices. Epilepsy affects more than 3.4 million people nationwide, of which approximately 500,000 are children, with greater than 200,000 first-time seizures each year.¹ Of the affected individuals, as many as 100,000 are estimated to experience status epilepticus (SE). Both general practitioners and neurologists alike must be able to define, recognize and treat seizure emergencies. This review article defines and describes SE, discusses the emergency evaluation and management of SE that is both new-onset and breakthrough in people with epilepsy, reviews the current treatment recommendations for SE in both the home and hospital settings, and introduces special populations that may be at high risk for SE or other seizure emergencies.

OBJECT: Many children with epilepsy and tuberous sclerosis complex (TSC) have multiple tubers on MR imaging and poorly localized/lateralized video electroencephalography (EEG) findings. Given the long-term risks associated with frequent seizures and multiple antiepileptic drugs, along with improved success in identifying focal epileptogenic zones in patients with multifocal lesions, the authors used bilateral intracranial EEG to lateralize the epileptogenic zone in patients with nonlateralizable noninvasive preoperative evaluations. METHODS: A retrospective analysis from January 1, 1998, to June 30, 2008, identified 62 children with TSC who were presented at a surgical conference. Of the 52 patients undergoing diagnostic or therapeutic procedures during the study period, 20 underwent bilateral intracranial EEG. The presurgical testing results, intracranial EEG findings, surgical interventions, and outcomes were reviewed. RESULTS: Fourteen of 20 patients had intracranial EEG findings consistent with a resectable epileptogenic zone. One patient is awaiting further resection. Five patients had findings consistent with a nonresectable epileptogenic zone, and 1 of these patients underwent a callosotomy. Seven patients had Engel Class I outcomes, 1 was Class II, 3 were Class III, and 3 were Class IV (mean follow-up 25 months). CONCLUSIONS: Bilateral intracranial EEG can identify potential resectable seizure foci in nonlateralizable epilepsy in TSC. Although 6 of 20 patients did not undergo resection (1 patient is pending future resection), significant improvements in seizures (Engel Class I or II) were noted in 8 patients. In the authors' experience, this invasive monitoring provided a safe method for identifying the ictal onset zone

Multicenter, retrospective analysis of 70 subjects with TSC following surgery for relief of epilepsy revealed significant associations between younger age at seizure onset, present/prior history of infantile spasms, interictal focality (bilateral versus unilateral), and absence of residual postoperative predominant tuber, and poorer postoperative outcome (p < 0.01). Ictal multifocality, mental retardation, and discordant EEG and MRI data showed a negative trend toward outcome, but were not significant

We retrospectively investigated outcome data for vagus nerve stimulation (VNS) in children less than 12 years of age with intractable seizures and mitochondrial disease. Five children with a mitochondrial disease, due to electron transport chain deficiency, were studied. Information was collected from clinic visits prior to, and subsequent to, VNS implantation. Data were collected by type and frequency of seizures, encephalogram and neuroimaging findings, and medication history. Four of the children had predominantly myoclonic seizures, while the other child had focal seizures with secondary generalization and myoclonic seizures. All five children did not have significant reduction in seizure frequency with VNS. VNS may not be an effective method to control myoclonic seizures in children with electron transport chain disorders

PURPOSE: Functional mapping of eloquent cortex with electrical neurostimulation is used both intra- and extraoperatively to tailor resections. In pediatric patients, however, functional mapping studies frequently fail to localize language. Wada testing has also been reported to be less sensitive in children. METHODS: Thirty children (4.7 - 14.9 years) and 18 adult controls (18-59 years) who underwent extraoperative language mapping via implanted subdural electrodes at the NYU Comprehensive Epilepsy Center were included in the study. Ten children and 14 adults underwent preoperative Wada testing. Success of the procedures was defined as the identification of at least one language site by neurostimulation mapping and determination of hemispheric language dominance on the Wada test. RESULTS: In children younger than 10.2 years, cortical stimulation identified language cortex at a lower rate than was seen in children older than 10.2 years and in adults (p<0.05). This threshold, demonstrated by survival and chi2 analysis, was sharply defined in our data set. Additionally, Wada testing was more likely to be successful than was extraoperative mapping in this younger age group (p<0.05). CONCLUSIONS: Analysis of our series demonstrates that language cortex is less likely to be identified in children younger than 10 years, suggesting that alternatives to the current methods of cortical electrical stimulation, particularly the use of preoperative language lateralization, may be required in this age group

In patients with tuberous sclerosis complex (TSC), the high rates of mental retardation are associated with cortical tubers, seizure activity, and genetic factors. The goal of the study was to investigate the relationship between bilateral cortical tubers and seizure variables and mental retardation in individuals with TSC. The records of 27 patients with TSC (age 6 months to 33 years) undergoing neuropsychological assessment and the following clinical variables were examined: bilateral versus non-bilateral cortical tubers, the age of seizure onset, and presence of infantile spasms. Results were statistically analyzed. Bilateral cortical tubers (p=0.02) and early age of seizure onset (p=0.04) were significantly related to impaired cognitive functioning. Only one of the seven patients with normal cognitive functioning had bilateral tubers, whereas 13/21 patients with intellectual impairment had bilateral tubers. Patients with normal cognitive functioning experienced a mean age of seizure onset after 6 years. A trend was observed between infantile spasms and cognitive functioning (p=0.06); the lack of statistical significance likely reflects the small sample size. Neither age nor gender was related to cognitive status. Further investigation incorporating additional neuroimaging factors, antiepileptic treatment effects, and genetic variables, is needed