Abstracts

Chronic medial temporal lobe epilepsy (MTLE) is associated with memory loss, due to damage in the hippocampal system. We studied 39 consecutive patients with refractory MTLE and unilateral hippocampal atrophy (HA) determined by volumetric magnetic resonance imaging (MRI). MRI studies included manual morphometry of T1 MRI with 1mm isotropic voxels that underwent field non-homogeneity correction and linear stereotaxic transformation into a standard space. Structures of interest comprised hippocampus, amygdala, entorhinal, perirhinal, parahippocampal, and temporopolar cortices. Neuropsychological evaluation included Wechsler Adult Intelligence Scale [ndash] Revised, Edinburgh Handedness Inventory, Dichotic Listening Test, Verbal Fluency Test, Boston Naming Test, Strub [amp] Black Vigilance Test, Trail Making Test, Winsconsin Card Sorting Test and Wechsler Memory Scale [ndash] Revised. The volumes of medial temporal lobe structures were compared to neuropsychological results, by means of Chi-square test and simple regression analysis. Significant positive correlations were found between volumes of left hippocampus and Verbal Memory (p=0.035), Verbal Fluency (p=0.019) and BNT (p=0.029); left perirhinal cortex and BNT (p=0.038); left entorhinal cortex and Verbal Fluency Test (p=0.023); and right parahippocampal cortex and Vigilance Test (p=0.042). On the other hand, the volumes of right hippocampus and right perirhinal cortex were negatively correlated to General Memory (p=0.042; p=0.019), Verbal Memory (p=0.013; p=0.004) and Verbal Fluency tests (p=0.008; p=0.002) and that of right entorhinal cortex, to Verbal Memory (p=0.028) and Verbal Fluency tests (p=0.013). In patients with left MTLE, the volume of left hippocampus correlated positively to verbal memory and language functions, while the volume of left perirhinal and entorhinal cortices correlated only to language function. On the other hand, in patients with right MTLE, reduced volumes of right hipocampus, right perirhinal and entorhinal cortices correlated with better performance on general and verbal memory, and language skills. (Supported by FAPESP: grant numbers 00/07788-2 and 00/04710-2)