GENDER DIFFERENCES IN POST-TEMPORAL LOBECTOMY VERBAL MEMORY AND RELATIONSHIPS BETWEEN MRI HIPPOCAMPAL VOLUMES AND PREOPERATIVE VERBAL MEMORY

Thirty-three men and 42 women who underwent left, and 26 men and 24 wo men who underwent right temporal lobectomy (TL) were studied retrospec tively to determine if there were sex differences in (1) verbal memory outcome, and (2) relationships between verbal memory and magnetic res onance imaging (MRI) hippocampal volumes. All patients were left hemis phere language dominant. The surgical specimen and MRI were consistent only with mesial temporal sclerosis (MTS). Verbal memory was evaluate d by Logical Memory percent retention (LMPER) from the Wechsler Memory Scale-Revised (WMS-R). Women experienced a significant improvement wh ile men experienced a significant decline in postoperative LMPER. The difference between right and left hippocampal volumes predicted verbal memory outcome in both men and women. Preoperative LMPER was positive ly correlated with both the left and right hippocampal volumes in left TL women only. No verbal memory sex differences or correlations betwe en LMPER and MRI data were found in the right TL group. The data suppo rt the presence of human neurocognitive sexual dimorphism. Verbal memo ry abilities supported by the hippocampus are less lateralized in wome n with left temporal lobe epilepsy and mesial temporal sclerosis. Wome n appear to have greater verbal memory plasticity following early left mesial temporal lobe insult.