Rapid eye movement sleep reveals epileptogenic spikes for resective surgery in children with generalized interictal discharges

Summary Objective Epilepsy surgery can be successful in children with extensive congenital or early acquired focal or hemispheric brain lesion on magnetic resonance imaging (MRI) despite generalized interictal epileptiform discharges (IEDs). The aim of this study was to assess if rapid eye movement (REM) sleep reduced generalized IEDs and revealed lateralized IEDs to identify the epileptogenic hemisphere in children with generalized IEDs and normal/subtle changes on MRI. Methods We studied 20 children with generalized IEDs on scalp electroencephalography (EEG) and normal/subtle changes on MRI who underwent intracranial video‐EEG for epilepsy surgery. We assessed a minimum of 100 IEDs during REM, non‐REM, and wakefulness, and assigned the distribution (generalized, left, or right hemisphere) to each IED. The number of lobes in the resected areas and seizure outcome were compared between 20 children with generalized IEDs and a comparison group of 28 children without generalized IEDs. Results The mean occurrence rate of generalized IEDs during REM (37%) was significantly lower than that during non‐REM (67%, p