[Neuropsychological study of dementia severity in Alzheimer's disease]

To investigate the neuropsychological pattern of different dementia severity in Alzheimer Disease (AD).

Probable AD patients who were examined with NINCDS-ADRDA criteria for clinical diagnosis of AD were further examined with several neuropsychological tests and the dementia severity was determined with clinical dementia rating (CDR).

There was impairement of visuospatial function in mild AD (CDR = 1). Evident decline was found in moderately severe AD (CDR = 2) and severe AD (CDR = 3). There was impairment of cognition function in mild AD and the decline continued in moderately severe and severe AD. Memory function declined apparently in the early stage of AD, but the decline was not apparent in moderately severe AD. However, the decline became very quick and memory function was completely lost in severe AD. The trend of decline of daily living activity and ability was the same as memory. Alteration in personality appeared in the mild AD and became most evident in severe AD.

Neuropsychological test is useful in diagnosis of AD in the early stage, and neuropsychological pattern in each stage is useful in differential diagnosis.