Detection of Interictal Epileptiform Activity during Spontaneous Sleep: An MEG-EEG Comparison

Introduction: Simultaneous interictal EEG and MEG sleep recordings were compared as to their sensitivity in the visual detection of focal epileptiform activity. Because MEG is indifferent to radial activity, i.e., sleep changes, a higher ratio of epileptic discharges (ED) unique to MEG compared to EEG was presumed in the case of overlapping sleep changes. Patients: We studied 14 children and adolescents aged 3.5–17 years with localization-related epilepsy. Methods: The 122-channel whole-head MEGs and 33-channel EEGs were recorded simultaneously for 20–40min, most of them in segments of 5–20min. Segments of artef…