ORIGINAL ARTICLE: Effect of normal aging on functional connectivity of the brain: an EEG study

• Published in: Psychogeriatrics Vol. 3; no. 2; pp. 49 - 53
• Main Authors: Shinosaki, Kazuhiro, Ishii, Ryouhei, Ukai, Satoshi, Mizuno-Matsumoto, Yuko, Inouye, Tsuyoshi, Tutiyama, Masato, Kaku, Tetsuji, Takeda, Masatoshi
• Format: Journal Article
• Language: English
• Published: 01.06.2003
• ISSN: 1346-3500; 1479-8301
• DOI: 10.1046/j.1479-8301.2003.00008.x

Background:Cognitive decline associated with normal aging, mild cognitive impairment (MCI) and Alzheimer's disease (AD) are, in theory, reflected in the disturbance of selective neural networks. Methods:The effect of aging on the functional connectivity of multiple areas of the brain was investigated by using relative power contribution (RPC) analysis of alpha activity. Electroencephalograms were recorded from eight channels in 38 healthy elderly subjects aged 50-89 years and in 22 control subjects aged 20-29 years. Results:Entropy of the RPC of alpha activity, indicating the amount of dependence in each area, showed a significant decrease in the left temporo-occipital area in 50-80-year-old subjects and in the right inferior frontal area in 70-80-year-old subjects. Conclusions:A metabolic decrease in these areas is also reported in patients with AD or MCI. The results from this study suggest that the normal aging process and pathological processes may exhibit a partially common pattern of neural degeneration. However, further studies are required using a larger sample size and strict discrimination between normal aging and MCI.