Automated electrical source imaging with scalp EEG to define the insular irritative zone: Comparison with simultaneous intracranial EEG

•Ictal or interictal epileptiform discharges originating in the insula are difficult to be detected by scalp EEG.•We evaluated the accuracy of automated low density electrical source imaging (ESI) to define the insular irritative zone by comparing ESI results with concomitant stereo-EEG.•ESI showed 53% overall accuracy, 55% specificity and 53% sensitivity and might be a useful tool in presurgical evaluation.