Neuropsychological Characteristics of Mesial Temporal Lobe Epilepsy: Lesion Laterality-Sex Interaction

ABSTRACT

BACKGROUND: Memory changes and its predictors after anterior temporal lobectomy (ATL) were investigated. A standardized regression-based (SRB) outcome methodology was used, accounting for the effects of practice and preoperative memory functions. METHODS: Consecutive 45 ATL patients (male 22) with mesial temporal sclerosis (dominant 21) who became seizure-free for at least 1 year postoperatively were included in the study. Wechsler Memory Scale-Revised(WMS-R) was performed pre- and postoperatively. Memory changes were estimated using SRB norms and then were correlated with age of onset, seizure duration, chronological age, seizure risk factors, and preoperative memory function. RESULTS: 1) The majority of cases (76~84%) showed no significant memory changes. Significant declines in verbal memory were noted for 8 (18%) out of 45 ATL patients whereas significant declines in visual memory were found in only 2 (4%). There were no differences in memory changes according to lesion laterality. 2) Later age at onset, shorter duration of epilepsy, absence of history of infection or febrile convulsion were significantly related to verbal memory decrease after ATL. 3) Using SRB methodology, adequacy of preoperative memory performance was correlated with decrease in visual memory but not in verbal memory, even if absolute change scores between pre-and postoperative values were associated with preoperative performances in both verbal and visual memory. CONCLUSIONS: Although group variability of memory outcome after ATL using WMS-R was not found to be significant, considerable individual variability of memory outcome after ATL was found along with significant predictors of postoperative verbal memory decrease. (J Korean Neurol Assoc 19(3):219~225, 2001)