Abstracts

Rationale: Intracranical electroencephalography (IEEG) plays an important role in guiding epilepsy surgery in pediatric epilepsy patients. Recently, there has been increased interest in higher frequency components of clinical IEEG recordings and their potential relationship to epileptogenic brain tissue but very little work has been performed with pediatric epilepsy surgical patients. As pediatric patients have predominantly neocortical epilepsy, often with focal cortical dysplasia as the underlying pathology, determining if HFOs can aid in the surgical evaluation is imperative. Methods: We employ a previously validated, automated high-frequency oscillation (HFO) detection algorithm to determine the prevalence of HFOs over prolonged, representative segments of IEEG recorded from 24 patients. Approximately 8 h of IEEG, 16 randomly selected 30-min segments of continuous interictal IEEG per patient, were analyzed. Results: The electrodes within the seizure onset zone were found to have significantly higher mean HFO activity averaged across these 16 segments in 12 of the twenty four patients. There was observed variability between individual 30-min segments in these patients, indicating that longer recordings of interictal activity improved localization.Conclusions: Our data suggest this method of automated HFO detection across long periods may be useful in planning epilepsy surgery in certain children with intractable epilepsy. Further research is required to help determine which patients would benefit from this technique.