Cognitive Decline in Patients with Alzheimer’s Disease: A Six-Year Longitudinal Study of Mini-Mental State Examination Scores

Abstract

The author of this chapter present six years of longitudinal data on Mini-Mental State Examination (MMSE) scores in Japanese patients with Alzheimer’s disease (AD). Fifty-eight subjects were treated with donepezil, and nineteen served as controls. The MMSE scores recorded at the first medical examination and at the one-, three- and six-year follow-up examinations were analyzed. Over six years, the mean MMSE scores fell from 21.9 to 15.0 in the medication group and from 21.6 to 10.2 in the control group. The difference in the rate of decline between the two groups was significant. In the medication group, subjects’ sex, age and severity of cognitive impairment at entry did not affect the rate of MMSE score decline. Thirty-two patients in the medication group remained residents during the six-year period (resident group), twenty-one began as residents but were subsequently institutionalized, and five were institutionalized from the outset. The rate of decline in MMSE scores was significantly smaller in the resident group than in the other two groups. These data suggest that donepezil contributes to long-term maintenance of cognitive ability in AD patients and that a residential community setting, which is rich in stimuli, suppresses cognitive decline.