PROGRESSION IN ALZHEIMERS-DISEASE - SEQUENCING OF NEUROPSYCHOLOGICAL DECLINE

The progression of cognitive and motor functions in Alzheimer's disease (AD) patients and healthy aged individuals was studied. For the healthy aged, the progress was negligible during a 2-year period. In the AD patients, there was a marked progression in all cognitive tests, but only a slight progression in the finger motor tests. Progression rate varied substantially across functions; the most rapid progression was seen in psychomotor speed, whereas the slowest was seen in episodic memory. The onset of decline was estimated to have occurred first in episodic memory, then in psychomotor speed, semantic memory, and visuospatial functions; finally and most recently, decline was estimated to have occurred in primary memory. The overall data pattern suggests that the onset as well as the rate of progression varies across cognitive functions, and that there may be a time-ordered sequence of decline of neuropsychological functions in AD that parallels the trajectory of neuropathological changes in this disease.