MEMORY PERFORMANCE ON THE INTRACAROTID AMOBARBITAL PROCEDURE AS A PREDICATOR OF SEIZURE FOCUS

The intracarotid amobarbital procedure (IAP) was performed on 56 patie nts with intractable complex-partial epilepsy who were candidates for temporal lobectomy. Seizure focus was lateralized to one hemisphere, a s determined by surface EEG recordings and MRI evidence of temporal lo be disease. IAP memory items were presented following injection of 125 mg of sodium amytal into the internal carotid artery. Verbal, Nonverb al, Design, Pictorial, and Total memory scores were calculated based o n recall/recognition of memory stimuli following drug recovery. Poorer memory was observed in the hemisphere ipsilateral to seizure focus on all memory scores. The Total Memory Score was the best memory measure , correctly classifying the largest number of patients. Using optimal cut-off scores on this measure, 75% of the patients with left hemisphe re seizure focus and 79% of the patients with right seizure focus were correctly classified. There was a definite tendency for the dominant hemisphere to outperform the non-dominant. This must be taken into acc ount in arriving at optimal cut-off points.