Visuospatial performance in very old demented persons: an individual difference analysis.

This study examines selected demographic, psychometric, and biological measures as predictors of visuospatial performance in a sample of 98 persons with mild to moderate dementia. Visuospatial performance was measured using standardized neuropsychology instruments, namely: Poppelreuter's figures, the clock test, and block design. Although multiple measures were initially correlated with performance on the selected visuospatial tests, the Mini-Mental State Examination was the exclusive predictor of Poppelreuter's figures and the clock test scores. For block design, years of education also contributed to the prediction model, but only among mildly demented persons. These results suggest that disease severity plays a dominant role in the prediction of visuospatial performance in dementia, particularly in more advanced stages of the disease. The differential role of education in predicting block design performance in mild vs. moderate dementia was also highlighted.