COST-EFFICIENT LOCALIZATION OF SEIZURES OF MESIOTEMPORAL ONSET WITH FORAMEN-OVALE ELECTRODES

Foramen ovale (FO) electrodes can identify mesiotemporal lobe (MTL) se izure onsets but are infrequently used in the USA. Ten patients with p resumed MTL ictal onset, unlocalized noninvasively, had FO electrodes inserted during long term monitoring for epilepsy. Placement was facil itated by intraoperative use of oblique submental and modified Caldwel l view, fluoroscopy. Eighty percent of patients had ictal localization by FO electrodes. This led to anterior temporal lobectomy in six with 83% being seizure free after follow-up of 20-32 months. The mean tota l costs of placing these electrodes was approximately half that of sub dural strips and a quarter that of depth electrodes. Foramen ovale ele ctrodes represent a cost-effective and efficient method of seizure loc alization when noninvasive workup suggests but is not definitive for M TL origin.