Spatially filtered magnetoencephalography compared with electrocorticography to identify intrinsically epileptogenic focal cortical dysplasia

This study was carried out to evaluate Synthetic Aperture Magnetometry-kurtosis (SAM(g2)), a spatially filtered source localization technique in magnetoencephalography (MEG), for identification of epileptogenic areas of focal cortical dysplasia (FCD). Three children with FCD were investigated to localize the ictal onset zone (IOZ). All patients subsequently had extraoperative electrocorticography (ECoG) for intractable epilepsy and surgical resection. SAM(g2) analysis showed overlapping of interictal MEG spike sources with the IOZ on ECoG in all children. We recommend MEG-SAM(g2) and MEG interictal spike source localization in patients with epileptogenic FCD.