PREDICTORS OF LONGITUDINAL CHANGES IN MEMORY, VISUOSPATIAL, AND VERBAL FUNCTIONING IN VERY OLD DEMENTED ADULTS

Longitudinal changes in memory, visuospatial and verbal functioning in a sample of demented persons were examined. The role of several demog raphic, psychometric, and biological indices in predicting the rate of cognitive deterioration was also investigated. The sample consisted o f 31 very old (mean age at entry = 83.5 years, range = 75-95) persons with Alzheimer's disease (n = 22) and vascular dementia (n = 9) from a community-based study. Subjects were tested on two occasions separate d by approximately 2.5 years. Results indicated significant longitudin al decline in verbal fluency and visuospatial ability, but only on 1 o f 3 measures of episodic memory. Results from regression analyses indi cated that a variety of putatively important variables, including age, gender, education, digit span, as well as a number of biological (vit amin B-12, TSH), dementia etiology, and psychometric (digit span) indi cators, exhibited no relationship to rate of memory, visuospatial, or verbal decline. The results suggest that the rate of cognitive deterio ration in dementia is highly variable, and this variability in change appears to include a variety of characteristics. A possible reason the reof may be that the role of individual-difference variables for cogni tive functioning in dementia is overshadowed by the pathogenetic proce ss itself.