Delayed recall in dementia: Sensitivity and specificity in patients with higher than average general intellectual abilities

Objective: Distinguishing early dementia from normal aging is especially di fficult in patients with higher than average intellectual abilities. To fin d signs useful in determining that the elderly "worried and well" are not i n an early phase of dementia, we compared the neuropsychological test perfo rmance of demented patients, patients who were not found to be demented, an d control subjects. Method: A retrospective study of neuropsychological tes t results from persons over 50 years of age who had an age-adjusted verbal intelligence quotient (VIQ) greater than or equal to 110, Analysis of covar iance (using age and education as covariates) was used to compare the norma l, no dementia, and dementia groups. Significant differences were further a nalyzed using Tukey's post hoc procedure. Tests on which the three groups d iffered at a p < 0.01 level were included in multivariate analyses. Results : The no dementia patient group performed at functional levels comparable t o those of the control group. By contrast, patients with dementia showed si gnificant impairment on tests of memory, naming, and visuospatial function compared with both the control and no dementia groups. Immediate and delaye d paragraph recall classified groups with a 96% specificity and 80% sensiti vity in the multivariate discriminant analysis. Conclusions: These results suggest that in patients with higher than average intelligence, the absence of a significant dementing process (as well as its presence) can be determ ined with reasonable probability.