Is streamlined evaluation of children for epilepsy surgery possible?

BACKGROUND: The presurgical evaluation of children with intractable epilepsy includes evaluation by an experienced clinician, MRI, video EEG, and functional imaging techniques to localize seizure onset. However, the contributions of each investigation to surgical decision making has not been systematically assessed. METHOD: Data used for decision on eligibility for surgery on 353 children was discussed at a presurgical multidisciplinary meeting and systematically recorded. The relationships between MRI, EEG, SPECT findings, and the probability of being offered epilepsy surgery were investigated retrospectively using a quick unbiased statistical tree (QUEST). RESULTS: Sixteen children were offered nonresective surgery. Of the remaining, 236 (70%) were offered resective surgery. The proportion of children with a localized lesion on MRI offered resective surgery was 92%[95% CI: 88 to 95%], and EEG telemetry did not modify decision making in this group (p < 0.001). In children with bilateral MRI changes or normal scan the probability of being offered resective surgery was 78% in those with localized ictal onset on EEG compared to 9% with nonlocalized EEG (p < 0.001). SPECT did not appear to systematically influence decision making in any group. CONCLUSION: Children with medically intractable epilepsy and localized lesions on MRI may not necessarily need ictal EEG recordings or SPECT prior to offering resective surgery. More targeted use of EEG telemetry could allow more children with less obvious surgical targets to be investigated without increasing resources.

Hippocampal sclerosis in children with lesional epilepsy is influenced by age at seizure onset.

PURPOSE: Hippocampal sclerosis (HS) is the most common lesion underlying drug-resistant temporal lobe epilepsy. Whether HS is a developmental or acquired pathology remains unclear. Whereas HS has been causally linked to prolonged febrile convulsions in childhood, evidence also exists that it may coexist with extrahippocampal abnormalities, the concept of "dual pathology." The aims of this study were to address whether hippocampal abnormality consistent with HS (a) occurs in children with lesional extrahippocampal epilepsy, (b) is more commonly seen in association with developmental rather than acquired extrahippocampal pathologies, and (c) whether any effect of age at seizure onset is found on the occurrence of HS in lesional extrahippocampal epilepsy. METHODS: Clinical and histopathologic data of patients having resective surgery for extrahippocampal epilepsy that included the hippocampus were investigated. RESULTS: Twenty-nine children were retrospectively included in this study, and 21 (72%) of 29 were found to have a hippocampal abnormality consistent with HS. No relation was noted between developmental or acquired extrahippocampal pathologies and the presence of hippocampal abnormality. Children with normal hippocampi on visual histologic assessment had a significantly younger age at seizure onset (p < 0.001). Duration of epilepsy was not correlated with the presence of hippocampal abnormality. CONCLUSIONS: Hippocampal abnormalities are seen in similar proportions with both acquired and developmental extra-hippocampal pathologies, suggesting that these abnormalities are the result of seizures from the focus that is remote from the hippocampus. In addition, children who have their initial seizure at an early age are less likely to develop seizure-induced hippocampal injury.