Differentiating Alzheimer's patients from the normal elderly and stroke patients with aphasia.

The performance of individuals with mild and moderate Alzheimer's disease (AD), normal age-matched elderly individuals, and stroke patients with fluent and nonfluent aphasia were compared on a group of neuropsychological tasks. The unique performance profiles associated with each subject group are discussed, and the best tasks for intergroup differentiation specified. Whereas the tasks employed were efficacious for discriminating early- and middle-stage AD patients from normal subjects and aphasic stroke patients, and early- from middle-stage AD patients, they were not efficacious for subtyping aphasia patients according to fluency. Generally, memory measures were best for intergroup differentiation.