J-GLOBAL ID:200904026297929273  Research Project code:0450021016 Update date:Dec. 15, 2003

Clinical neurophysiological studies in normal and neurological disorders: Quantitative EEG study in vascular dementia

神経疾患および健常人の神経生理学的研究 定量的脳波解析による血管性痴呆の診断
Study period:2002 - 0
Organization (1):
Investigating Researcher (1):
Research overview:
Statistical comparison of quantitative electroencephalogram findings of clinically diagnosed Alzheimer's disease (AD) patients with those of healthy volunteers was performed to elucidate the changes in electroencephalogram of vascular dementia (VaD). The subjects included 10 patients diagnosed as having mild to moderate AD on NINCDS-ADRDA and DSM-IIIR referring the results of radiological image findings, Hachinski Ischemic Score, HDS-R and WAIS-R, 10 patients diagnosed as having VaD and 20 healthy age matched volunteers, and quantitative analysis of their electroencephalograms was carried out. The electroencephalogram was recorded under resting state with closed eyes condition and induced from 16 electrodes positioned according to 10-20 international method. The frequencies were analyzed every 1 Hz from 2.0 to 19.8 Hz. In addition, the ratios of alpha and beta wave areas to the power in slow wave area, that is Power Ratio Index (PRI) was obtained. The individual case was statistically compared with the control group using Student-t test. The distribution for every 1 Hz power showed peak at 9-10 Hz in alpha spectrum in healthy control group. While AD group showed a slower peak at 8-9 Hz and VaD group showed peak at delta spectrum. Both AD and VaD groups showed significant increase of PRI in all electrodes in comparison to those of healthy volunteers. The AD group showed significant increase of PRI in left hemisphere dominant bilateral occipital and parietal regions. While VaD group showed marked increase of PRI than that of AD group, particularly significant in bilateral frontal region. VaD group extensively showed strongly slowed wave in basal rhythm than that of AD group. AD group showed slower wave mainly in occipital and parietal regions, while VaD group showed frontal region dominant slow wave. That is, delta wave was more strongly observed in VaD group in comparison to that of AD group, that might be reflected from pathological conditions having more abundant subcortical lesions.

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