A clinical and autopsy study of dementia in Olmsted County, Minnesota, 1980-1981

The clinical records and autopsy protocols were studied from 350 cases in which an autopsy was done in Olmsted County, MN, in 1980 and 1981. Overall autopsy rate was 33.6%, and autopsy rate for those aged 60 years or more was 29%. Preselected criteria were used for diagnosis of dementia. Thirty-two demented and 68 nondemented patients had complete autopsies; all were more than 60 years old. Twenty-three of 32 (72%) demented patients had Alzheimer's disease. The frequency of cerebral infarcts among the nondemented patients was significantly higher than among the demented patients (p = 0.02).