Cognitive and functional status of the oldest old

OBJECTIVE: To compare the cognitive performance and functional status of the normal oldest old (85+ years) with that of normal older persons aged 65 to 84 years to identify age-associated changes in cognition in individuals considered clinically normal. BACKGROUND: Advancing age appears to be a risk factor for dementia. DESIGN/METHODS: Analysis of performance on an extensive neuropsychological battery and the Pfeffer Outpatient Disability Scale in 243 normal individuals age 65 to 99 years. RESULTS: Fifty-two normal subjects who were 85 years of age and older (mean age 88.2 +/- 3.1) and 191 normal subjects aged 65-84 years (mean age 75.8 +/- 5.0) were compared. Mean education for both groups was not statistically different. No significant differences in functional disability were found between the two groups. Normal subjects aged 85 years and older performed significantly less well than their younger counterparts on verbal and nonverbal memory, psychomotor/executive tasks, and category verbal fluency. CONCLUSIONS: Advancing age in normal subjects is accompanied by a decrease in cognitive function, measured by various neuropsychological tests, but is not accompanied by functional impairment.