Cerebrovascular pathology and dementia in autopsied Honolulu-Asia aging study participants

Clinicopathologic data from 285 autopsies were analyzed. The decedents were long-standing participants in the Honolulu-Asia Aging Study, a prospective epidemiologic investigation of stroke, neurodegenerative diseases, and aging. We assessed the prevalence at death of four primary neuropathologic processes using specific microscopic lesions as indicators. An algorithm was developed to assign each decedent to one of six subsets, corresponding to pathologic dominance by microvascular lesions (14% of decedents), Alzheimer lesions (12%), hippocampal sclerosis (5%), cortical Lewy bodies (5%), codominance by two or more primary processes (9%), or without a dominant pathologic process recognized (55%). Definite or probable dementia had been identified in 118 of the decedents. The proportions of men in each subset identified as demented were (in the same order) 57%, 53%, 79%, 57%, 76%, and 25%. In this autopsied panel of older Japanese-American men, the importance of microvascular lesions as a likely explanation for dementia was nearly equal to that of Alzheimer lesions. The cerebrovascular lesion type most essentially and inclusively related to dementia was multiple microinfarction.