CLINICOPATHOLOGICAL CORRELATES IN ALZHEIMER-DISEASE - ASSESSMENT OF CLINICAL AND PATHOLOGICAL DIAGNOSTIC-CRITERIA

The neuropathologic findings from a group of 123 patients who have com e to autopsy from the Rochester Alzheimer Disease Project (RADP) are p resented. Among these 123 cases, there were 94 demented subjects who m et the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer Disease and Related Disorders Association (NINCDS -ADRDA) clinical criteria for the diagnosis of ''probable Alzheimer di sease,'' and 29 normal elderly controls. Autopsy confirmation of Alzhe imer disease (AD) was based on the a age-graded National Institutes of Health (NIH) consensus conference pathologic criteria. Using the NINC DS-ADRDA clinical criteria and the NIH pathologic criteria, the diagno stic accuracy was 88%, the sensitivity was 98%, and the specificity wa s 69%. Additional strict clinical and pathologic criteria developed by the RADP were applied in the final review of these cases to exclude a ll confounding causes of dementia, including cerebral infarcts. After applying these additional criteria, a subset of 62 cases of ''pure'' A D and ''pure'' control subjects was identified for a more detailed exa mination of neuritic plaques (NP) and neurons containing neuro-fibrill ary tangles (NFT). The NP and NFT were counted in three subfields of h ippocampus and two areas of association neocortex. The density of diff use plaques (plaques lacking dystrophic neurites) was estimated on a s emiquantitative basis. Results show that the AD patients and control g roups could be distinguished from each other easily on the basis of me an NP and NFT counts, but there was sufficient overlap in the counts t o present difficulty in diagnosing any individual case. Abundant diffu se plaque involvement and NFT in the neocortex were, however, seen onl y in AD cases.