Abstracts

Patients with left temporal lobe epilepsy show cognitive imparment in episodic memory. Semantic memory aspects have received less attention in temporal lobe epielpsy. We evaluated aspects of semantic memory in epileptic patients with temporal lobe epilepsy secondary a mesial temporal sclerosis. We studied patients with medically refractory mesial TLE undergoing presurgical evaluation for epilepsy surgery with MRI documented unilateral mesial temporal sclerosis. Patients were classified as right or left mesial temporal sclerosis (MTS), according to MRI findings. Inclusion criteria included right handed patients with ages between 18-55, education above 8 yrs and absence of other MRI lesions or other significant neurological or psychiatric disease. Patients underwent a detailed battery evaluating episodic memory (word list learning, with spontaneous, cued and recognition recall and imediate and late history recall) and semantic memory tests: picture-word matching, definition of objects, common nouns, verbs and adjectives, word list generation [FAS, and category: animals and means of transportation), auditory responsive and visual confrontation naming (common and proper nouns, verbs and adjectives). Performance of left and right MTS patients was compared with a control group of normal individuals, matched by age, gender and education. We evaluated 18 MTS patients (10 left, 8 right) and 22 controls. Groups did not differ in age, gender and education. All patients were high dose mono or polytherapy of antiepileptic drugs. Left MTS patients performed significantly worse than controls in immediate and late history recall (p[lt]0.05). Left MTS patients also performed worse than right MTS and controls in word list learning, but the difference did not reach statistical significance(p[lt]0.05). In semantic memory testing, both left and right MTS patients performed significantly worse than controls in confrontation naming for common and proper nouns, as well as in word list generation (FAS, animals and means of transportation). In word-picture matching, right MTS patients performed significantly worse than controls (p[lt]0.05). Left MTS patients performed worse than controls, but this difference did not reach statistical significance (due to sample size). Left and right MTS patients performed worse than controls in responsive naming and in visual confrontation for verbs and adjectives, but this difference did not reach statistical significance. Groups did not differ in the definition task for objects, nouns, adjectives and verbs. In this group of patients, while episodic verbal memory impairment was noted in left MTS patients, imparment in some aspects of semantic memory was seen in both left and right MTS patients.