The role of the intracarotid amobarbital procedure in evaluation of patients for epilepsy surgery.
OBJECTIVE
To examine the role of the intracarotid amobarbital procedure (IAP) in the presurgical evaluation of patients with medically refractory localization-related epilepsy.


METHODS
We retrospectively studied 111 patients who underwent cortical resective surgery at our center between 1991 and 1996. In patients with mesial temporal lobe epilepsy (mTLE), a presurgical determination of the epileptogenic zone was compared with localization based on IAP memory asymmetry scores, and with ultimate localization after resective surgery. In patients with neocortical or mesial frontal epilepsy, the IAP was evaluated for evidence of unilateral or bilateral poor memory performance.


RESULTS
Of 68 patients with mTLE localized by noninvasive tests, 60 had concordant lateralized memory deficits on IAP. Eight patients had lateralized memory deficits on IAP that were discordant with noninvasive tests and with localization as determined by surgical outcome. All 11 mTLE patients requiring invasive EEG monitoring were correctly lateralized by IAP, including one patient in whom the noninvasive evaluation otherwise provided false lateralization. Of 32 patients with neocortical or mesial frontal lobe epilepsy, 21 displayed memory deficits on IAP. Of 10 patients with bilateral deficits, five had mesial frontal lobe epilepsy. In 13 patients with lateralized memory deficits, seven underwent electrode implantation in the mesial temporal lobe, and four ultimately underwent resection of an epileptogenic mesial temporal lobe in addition to a neocortical resection.


CONCLUSIONS
In patients with mTLE, lateralized memory deficits on IAP usually confirm localization provided by noninvasive tests. However, in mTLE not well lateralized by the noninvasive evaluation, and in neocortical or mesial frontal epilepsy, the IAP may provide information regarding localization that ultimately alters surgical management.
Spencer
D C
DC
Department of Neurology, Oregon Health Sciences University, Portland, USA. spencerd@ohsu.edu
Morrell
M J
MJ
Risinger
M W
MW
D000293:Adolescent; D000328:Adult; D000654:Amobarbital / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000502:physiology; D002343:Carotid Artery, Internal; D002648:Child; D004569:Electroencephalography / Q000187:drug effects; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D017034:Epilepsy, Frontal Lobe / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology / Q000601:surgery; D007839:Functional Laterality / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007269:Injections, Intra-Arterial; D008297:Male; D008568:Memory / Q000187:drug effects* / Q000502:physiology; D008875:Middle Aged; D019579:Neocortex / Q000503:physiopathology / Q000601:surgery; D009483:Neuropsychological Tests; D012189:Retrospective Studies; D013702:Temporal Lobe / Q000503:physiopathology / Q000601:surgery
D000654:Amobarbital