Role of the Neuropathology of Alzheimer Disease in Dementia in the Oldest-Old

Abstract

Neuritic plaques (NPs) and neurofibrillary tangles (NFTs), mainly in the neocortex, the entorhinal cortex, and the hippocampus, represent the hallmark neuropathological lesions of Alzheimer disease (AD). Most studies have found the densities of NPs and NFTs to be associated with the severity of cognitive deficits, although the relative contributions of NPs and NFTs to cognitive dysfunction continue to be debated.^1-8 The different neuropathological diagnostic systems in common use, such as the Khachaturian criteria,⁹ the Consortium to Establish a Registry for Alzheimer Disease (CERAD) criteria,¹⁰ and the National Institute on Aging–Reagan Institute criteria,¹¹ use the density of these lesions and their association with dementia to arrive at a diagnosis of AD with varying degrees of certainty.