Memory Functions of Temporal Lobe Epileptic Patients in the Intracarotid Amobarbital Procedure:I. Lateralizing Value

ABSTRACT

BACKGROUNDS To examine the effects of seizure laterality and stimulus type on Wada memory performance in patients with temporal lobe epilepsy(TLE). METHODS: The subjects were 43 patients with medically intractable TLE (left TLE 26, Right TLE 17) who had no or rare seizures after surgery. The memory stimuli were concrete figures for some subjects and abstract figures for the other subjects. RESULTS: A clinical criterion of at least 2-points difference between left and right injections correctly classified 31(72%) patients into left and right TLE groups, with 4(9%) patients falsely classified. A discriminant function analysis(DFA) based on left and right injection scores allowed for a correct classification of 37(86%) patients into left and right TLE groups. When the memory stimuli were concrete figures, the correct classification rate was greater for right than left TLE patients. In contrast, with abstract figures, the correct classification rate was greater for left than right TLE patients. CONCLUSIONS: The Wada memory test is a valuable diagnostic aid in lateralizing temporal epileptogenic foci. Stimulus type as well as seizure lateralization is a major determinant of Wada memory asymmetries.