Cognitive impairment of Alzheimer disease.

The clinical signs of Alzheimer Disease can be quantitated and correlated with neuropathological evidence of the disease. These clinical signs which include amnesia, aphasia and apraxia can be screened for using instruments such as the Mini-Mental State Exam. In addition, each of these cognitive functions can be quantitated using specific tests. Standardized scores are available for a mini mental state but further research is needed to develop normative data for more detailed psychological assessment tests of specific cognitive deficits. The fact that the cognitive impairment predicts the neuropathology and also the presence of a familial disorder, provides the basis for the validity of these characteristic cognitive signs and the rationale for developing more standardized versions of these tests.