Abstract
The purpose was to evaluate the usefulness of cognitive examinations for differentiating Pick complex (PiC) from Alzheimer's disease (AD). The patients included 11 with frontotemporal dementia (FTD), 17 with primary progressive aphasia (PPA), 3 with semantic dementia and 24 with probable AD. All patients were examined using the Wechsler Adult Intelligence Scale Revised (WAIS-R), Mattis Dementia Rating Scale (DRS), Western Aphasia Battery (WAB) and Frontal Behavioral Inventory (FBI). We measured regional brain volumes using brain MRI and a computer program. We compared results of the examinations among the clinical groups, applied discriminant analysis to predict the most useful examination to classify groups, and correlated cognitive functions with brain volume. The results showed a significant difference in the scores of FBI and some subtests of DRS and WAIS-R between PiC and AD, and in the scores of WAB among the clinical types of PiC. Discriminant analysis showed that FBI was a significant discriminant factor, classifying 69.6% of the patients correctly. In FTD and PPA, scores of WAB and WAIS-R showed a trend toward correlation with the total brain volume, while the results of language-dependent examinations (WAB, DRS, verbal portion of WAIS-R) correlated significantly with the left frontotemporal or parietal brain volumes. We used brain volume ratios in order to eliminate various factors influencing brain volume. The results of WAB and DRS showed a tendency toward correlation with the left temporal ratio only in PPA. We concluded that FBI may be useful in discriminating PiC from AD, and WAB in discriminating PPA from FTD and AD. Based on brain volume-cognition relationship being observed only in PiC, we assumed that dementia in PiC comprises an accumulation of region-specific cognitive deficits, while dementia in AD is based on impairment of more diffusely distributed cognitive functions.
