Abstracts

Rationale: Corpus callosum section has been used to treat patients (usually children) with secondary generalized epilepsy (Lennox-Gastaut and Lennox-like syndromes). Although a good outcome has been reported in this patient population, no clear-cut outcome predictors have been described.Methods: Thirty-two patients submitted to callosal section (out of a series of 200 patients) were considered non-responders (less than 50% seizure frequency reduction) and were included in this study. General demographics (sex, age of seizure onset, age at surgery), EEG characteristics, seizure types, MRI findings and callosal thickness were studied as potential outcome predictors.Results: Children do not presenting with atonic seizures as the main seizure pattern and the presence of a thin corpus callosum were the only variables associated with a bad outcome after callosal section in this series.Conclusions: Callosotomy is an efficacious procedure in children with secondary generalized epilepsy. Post-operative outcome is stable in the majority of the responders, but is consistently bad in children with thin corpus callosum and without atonic seizures. Since corpus callosum fibers are collaterals from cortical neurons, children with thin corpus callosum might also be those with lower neuronal density.