Synthetic aperture magnetometry analysis of epileptic fast oscillation of MEG

Abstract The interictal MEG was investigated retrospectively to explore the epileptic fast oscillation. The source of the oscillation was analyzed by the SAM-VS method. The localization of the ECD analysis and the source of the oscillation by the SAM-VS method were compared with the MRI findings and the surgical area. MEG data in 5 of the 38 epilepsy patients (13%) included the epileptic fast oscillation. All five cases had the lesion in the MRI. ECD analysis indicated the unilateral lesion in the cases of two TLE, but the distribution of dipoles was scattered in another two TLE and one FLE. SAM-VS analysis of the epileptic fast oscillation succeeded in disclosing the source of the oscillation in all of the five cases. The epileptic region which SAM-VS analysis indicated was closely localized in the lesion of the MRI, which was confirmed as the epileptogenic lesion by the surgery.