Preoperative EEG correlates of seizure outcome from epilepsy surgery in children

Abstract

To identify criteria for selecting pediatric candidates for cortical resection, we compared preoperative standard EEGs, extracranial or intracranial (subdural strip or grid) electrode EEG-video monitoring and imaging studies, and surgical pathology findings with long-term (mean = 6.1 years) seizure outcome. Of 47 children, 83% were either seizure-free or substantially improved. Children with a predominant single interictal focus in standard EEGs over time or with seizures that were mostly well localized (even with equal numbers of bilaterally independent spikes) during monitoring had significantly better outcomes than those who had mostly diffuse or bilaterally independent interictal and ictal discharges. Factors not associated with poor outcomes were some seizures unaccompanied by ictal EEG patterns, spikes in postresection electrocorticograms, extratemporal resection, younger age at surgery, and older age of seizure onset. Significantly more patients with than without tumors were seizure-free. Significantly more preteenagers than teenagers had poorly localized interictal and ictal discharges.