Measuring dementia: assessment of multiple deficit domains.

A fundamental problem in the assessment of dementia is the brief, but adequate measurement of intellectual impairment. We evaluated 82 demented patients of heterogeneous etiology with 21 neuropsychological tests. Factor analysis identified five deficit domains among the tests: verbal ability, visuospatial ability, verbal memory, orientation, and concentration. One test was selected from each domain to form a Brief Battery for Dementia (BBD), which was used to explore the relationship between deficit patterns and disease characteristics. The pattern of deficits among the five tests altered with increasing disease severity: Logical Memory (a test of verbal memory) was severely impaired in the earliest stages, while tests of verbal concept formation, perceptual organization, and orientation declined more slowly. This battery discriminated between demented and normal subjects, with a sensitivity of 91% and specificity of 97%. Disease severity appeared to be a primary determinant of degree, number, and pattern of deficits in dementing disorders and may be an important factor that modulates the apparent discriminating power of intellectual tests.