Longitudinal changes in regional cerebral blood flow in a normal elderly group.

Only one published study to date has examined longitudinal age-changes in regional cerebral blood flow (rCBF) in an elderly group. It found rCBF declined significantly in their elderly sample over a 24 to 42 month period. The current study attempts to cross-validate the earlier study's findings with an older normal elderly group and a longer time interval between rCBF studies. This study is consistent with that investigation. The normal elderly did exhibit significant declines in blood flow across a variety of indices including: gray and white matter and the Initial Slope Index. These declines were generally on the order of.50 to.75 of a standard deviation loss. No significant differences in blood flow decline between males and females were discerned. While the young-old did exhibit greater blood flow than the old-old there were no significant differences in the rate of decline between the two age-groups.