Discrete gamma oscillations identify the seizure onset zone in some pediatric epilepsy patients

Intracranial 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. We employ a previously validated, automated discrete gamma oscillation (GO) detection algorithm to determine the prevalence of discrete gamma events over prolonged, representative segments of IEEG recorded from ten patients. Approximately 8 h of IEEG, 16 randomly selected 30-min segments of continuous interictal IEEG per patient, were analyzed. The electrodes within the seizure onset zone were found to have significantly higher mean GO activity averaged across these 16 segments in five of the ten patients. There was observed variability between individual 30-min segments in these patients, indicating that longer recordings of interictal activity improved localization. Our data suggest this method of automated GO 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.