Abstracts

To study to what extent hippocampal volume loss in patients with temporal lobe epilepsy (TLE) is associated with correlated loss in cortical gray matter amount throughout the entire brain. In 16 patients with TLE and unilateral hippocampal sclerosis on T2-weighted images, hippocampal volumes were measured using manual segmentation. Furthermore, cortical [lsquo]local gray matter amount[rsquo] (LGM) throughout the brain was estimated in each patient using voxel-based morphometry. Then, hippocampal volumes were correlated with whole-brain LGM of each patient. In order to improve statistical power, the LGM data of each patient were flipped such that hippocampal sclerosis was on the left in all patients. Hippocampal volumes correlated with LGM of the parahippocampal region, anterior and posterior cingulate, ventral striatum, basal and medial forebrain, anterior and mediodorsal thalamus and insula. The degree of atrophy in the sclerotic hippocampus is not regionally limited but is accompanied by correlated loss of gray matter volume in the extended limbic system. Therefore, dysfunction of the sclerotic hippocampus can be expected to be accompanied by more widespread limbic system dysfunction. (Supported by Volkswagenfoundation)