BACKGROUND: Vascular dementia (VD) has been held responsible for the majority of all dementia cases in both epidemiological and neuropathological studies in Japan. The aim of this study was to clarify relative frequencies of dementia neuropathologically in Japanese nursing home residents over a 17-year period and to clarify the gender and age effect on the relative frequencies. METHODS: Three hundred ten aged nursing home residents (146 men and 164 women), including dementia cases in Shimane prefecture, Japan, were evaluated clinically and neuropathologically over a period of 17 years. RESULTS: One hundred twenty-two (48 men and 74 women) of the 310 autopsied (39%) had shown signs of dementia during their lives. In classifying dementia type, Alzheimer's disease (AD) accounted for 34% (41); VD 35% (42); mixed dementia 11% (14); and "other" dementia 20% (25) of all samples. As to the gender and age effect, the most characteristic findings were as follows: (a) There were only VD cases in the 57-69-year-old group; (b) the 70-79 male age group lacked any cases with only AD; (c) more AD than VD was found in elderly men; and (d) in women, AD was the major cause of dementia in total. CONCLUSIONS: VD is responsible for the major cause of dementia in the younger women and the men under 90 years of age; AD is the leading cause of dementia in the elderly men and the women over 79 years of age in nursing homes, Shimane prefecture, Japan.
BACKGROUND:Vascular dementia (VD) has been held responsible for the majority of all dementia cases in both epidemiological and neuropathological studies in Japan. The aim of this study was to clarify relative frequencies of dementia neuropathologically in Japanese nursing home residents over a 17-year period and to clarify the gender and age effect on the relative frequencies. METHODS: Three hundred ten aged nursing home residents (146 men and 164 women), including dementia cases in Shimane prefecture, Japan, were evaluated clinically and neuropathologically over a period of 17 years. RESULTS: One hundred twenty-two (48 men and 74 women) of the 310 autopsied (39%) had shown signs of dementia during their lives. In classifying dementia type, Alzheimer's disease (AD) accounted for 34% (41); VD 35% (42); mixed dementia 11% (14); and "other" dementia 20% (25) of all samples. As to the gender and age effect, the most characteristic findings were as follows: (a) There were only VD cases in the 57-69-year-old group; (b) the 70-79 male age group lacked any cases with only AD; (c) more AD than VD was found in elderly men; and (d) in women, AD was the major cause of dementia in total. CONCLUSIONS: VD is responsible for the major cause of dementia in the younger women and the men under 90 years of age; AD is the leading cause of dementia in the elderly men and the women over 79 years of age in nursing homes, Shimane prefecture, Japan.