Diagnostic criteria for the neuropathological assessment of Alzheimer's disease: current status and major issues.

A Consensus Conference focusing on Alzheimer's disease (AD) took place in November 1996 to recommend uniform evaluation procedures and diagnostic criteria, co-sponsored by the National Institute on Aging and the Reagan Institute of the Alzheimer's Association. In conjunction with this conference, we reviewed diagnostic practices in current use, together with various neuropathological criteria proposed since 1985. Difficulties were identified in developing "gold standard" criteria for diagnosis and case classification of AD based upon the current state of knowledge. Working criteria for use within research contexts were proposed that acknowledged the realities of scientific limitations by inclusion of a broad and heterogeneous category of "uncertain" cases. (Eventually, methods will be developed for identifying these cases as preclinical AD, dementia due to multiple causes or non-AD, but this is not now possible.) Within applied contexts, the use of CERAD guidelines was supported. Finally, recommendations generated at the Consensus Conference were discussed, emphasizing the rapid pace of recent scientific advancement and the need for ongoing empirical reevaluation and modification of the Group's proposal.