Cognitive function in Japanese centenarians according to the Mini-Mental State Examination

We examined the effect of aging on cognitive function at the limit of human life expectancy by characterizing state of cognition in centenarians without clinical cognitive impairment.

Participants were 68 centenarians without cognitive impairment (Clinical Dementia Rating (CDR) 0), 96 controls 60 to 74 years old, and 46 controls 75 to 89 years old. We visited the places where centenarians were living and administered the Mini-Mental State Examination (MMSE) individually. Control subjects came to the assembly hall within their dwelling area, to be administered the MMSE.

Mean total scores of centenarians (22.3) were lower than for either 60-74 (27.2) or 75-89 (26.2). Comparison of scores in each of five cognitive domains measured by MMSE showed a significant age-group effect upon orientation, memory, and attention. Centenarians' scores were lower than for younger groups in every domain except for the language and praxis, concentration, and for repetition.

The centenarians' scores in memory and orientation declined as in earlier studies of normal aging. Centenarians' scores for attention and concentration differed from those in previous studies. The present result suggests that even primary memory is influenced by advanced age in centenarians, while ability to store information declines, ability to process is maintained.