Clinical Characteristics of Vascular Dementia

Abstract

Vascular dementia (VD) is the most common type of dementia in elderly Japanese, but recently senile dementia of Alzheimer type (SDAT) has increased with the prolongation of average life span. We investigated the characteristics of VD using a neuropsychological battery, electrophysiological examinations, and neuroimaging. VD and SDAT were diagnosed by DSM-IV and ADDTC-92. The depressive state was evaluated by Zung’s self-rating depression scale. Event-related evoked potential P3 was examined using the modified odd-ball task. Visuospatial attention was evaluated by eye camera, and Regional cerebral blood flow (rCBF) was examined by SPECT. Depressive state was observed to be significantly higher in the VD group than in the SDAT group (48% vs. 25%). Latency of novelty P3, which related frontal lobe function, was significantly prolonged in VD and that of target P3, which related temporoparietal lobe function, was prolonged in SDAT. Visuospatial attention was unstable against target in VD and fixed on central target in SDAT, and the rCBF study revealed frontal dominant reduction of CBF in VD and temporoparietal reduction in SDAT. We concluded that VD is mainly characterized by frontal dysfunction caused by subcortical disconnection.