title: Electric source imaging in temporal lobe epilepsy.
abstract: The objective of this study was to determine the validity of interictal spike (IIS) source localization in temporal lobe epilepsies (TLE) using stereoelectroencephalography as a validating method. Twenty patients with drug-resistant TLE were studied with high-resolution EEG and stereoelectroencephalography. Sixty-four scalp channels, a realistic head model, and different algorithms were used. For each patient, the intracerebral interictal distribution was studied and classified into one of three groups: L (mainly lateral), ML (mediolateral), and M (medial). In group L (three patients), surface IIS were recorded with a high signal-to-noise ratio. Source localizations designated all or part of the intracerebral interictal distribution. In group ML (11 patients), 8 patients had surface IIS, only 5 of which were localizable. High-resolution EEG permitted localization of the more lateral portion and definition of its rostrocaudal extension. A common pattern was identified in three patients with a predominant role of the temporal pole. In group M (six patients), four patients had rare surface IIS, none of which were localizable. Surface EEG does not record IIS limited to medial temporal lobe structures. In TLE with a mediolateral or a lateral interictal distribution, only the lateral component is detectable on surface EEG and accurately localizable by source localization tools.
authors.affiliation: Laboratoire de Neurophysiologie et Neuropsychologie, INSERM E 9926, Faculté de Médecine, Marseille, France. martine.gavaret@medecine.univ-mrs.fr
authors.forename: Martine
authors.initials: M
authors.lastname: Gavaret
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Badier
authors.forename: Patrick
authors.initials: P
authors.lastname: Marquis
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bartolomei
authors.forename: Patrick
authors.initials: P
authors.lastname: Chauvel
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D013238:Stereotaxic Techniques