The objective of this study was to determine the frequency and possible cognitive effect of histological Alzheimer’s disease (AD) in autopsied older nondemented individuals. The participants of this research were ninety-seven nondemented participants who were age 60 years or older at death (mean = 84 years). Results: About 40% of nondemented individuals met at least some level of criteria for neuropathological AD (npAD); when strict criteria were used, about 20% of cases had npAD. Substantial overlap of Braak neurofibrillary stages occurred between npAD and no-npAD cases. Although there was no measurable cognitive impairment prior to death for either the no-npAD or npAD groups, cognitive function in nondemented aging appears to be degraded by the presence of neurofibrillary tangles (NFTs) and senile plaques (SPs). It was concluded that europathological processes related to AD in persons without dementia appear to be associated with subtle cognitive dysfunction and may represent a preclinical stage of the illness. By age 80–85 years, many nondemented older adults have substantial AD pathology. (Author/publisher)
Samenvatting