EXTRAPYRAMIDALISM IN ALZHEIMERS-DISEASE - PREVALENCE, PSYCHIATRIC, AND NEUROPSYCHOLOGICAL CORRELATES

The prevalence and clinical correlates of extrapyramidal signs in a co nsecutive series of 78 patients with Alzheimer's disease attending a n eurology clinic, and 20 age comparable normal controls, were examined. Based on the unified Parkinson's disease rating scale (UPDRS) finding s, 18 patients (23%) met criteria for parkinsonism, 44 (56%) had isola ted extrapyramidal signs, and 16 (21%) had no extrapyramidal signs. Wh ereas the control group showed a simliar prevalence of isolated- extra pyramidal signs (57%), none of them showed parkinsonism. No significan t differences were found for age, sex, duration of illness, and severi ty of dementia among the three Alzheimer's disease groups. Patient's w ith Alzheimer's disease-parkinsonism, however, showed a significantly higher frequency of major depression and dysthymia and significantly h igher Hamilton depression scores than patients with isolated or no ext rapyramidal signs. Patients with Alzheimer's disease-parkinsonism also show significantly more deficits on frontal lobe related tasks such a s the Wisconsin card sorting test, trail making test, and verbal fluen cy, as well as on tests of constructional praxis and abstract reasonin g than patients with Alzheimer's disease but no extrapyramidal signs. In conclusion, the study showed a specific association between Alzheim er's disease and parkinson, as well as significant relationships betwe en parkinsonism, deficits in executive functions, and depression among patients with Alzheimer's disease.