Relation of linguistic communication abilities of Alzheimer's patients to stage of disease.

A battery of linguistic communication (L-C) tasks was administered to 152 Alzheimer's disease patients in different stages of the disease and 60 normal elders. Subject performance data are used to construct a profile of L-C deficits by disease stage, as determined by ratings on the Global Deterioration Scale. Specification also is made of the L-C tasks on which mild Alzheimer's patients perform like normal elders, the relative difficulty of various L-C processes, the disease stage in which the greatest change occurs in L-C functions, and the degree of variation in L-C for individuals at a particular level of dementia severity.