Extrapyramidal signs in Alzheimer's disease: a 3-year follow-up study.

Occurrence of extrapyramidal signs was investigated in a follow-up study of 32 patients with probable Alzheimer's disease (AD). Bradykinesia and rigidity were observed in 39% and 11% of the neuroleptic-free patients at entry and in 72% and 61% at year 3, respectively. Tremor was not a predominant feature nor did its occurrence increase over time. Use of neuroleptics contributed to extrapyramidal signs; 75-100% of the neuroleptic-treated patients showed bradykinesia, rigidity or orofacial dyskinesia. The homovanillic acid (HVA) concentrations of the cerebrospinal fluid at entry were comparable to those of age-matched controls. Nor did HVA levels correlate with rigidity or bradykinesia in these early AD cases. Presence of bradykinesia or rigidity at the initial evaluation predicted more severe dementia and a poor prognosis over the period of 3 years, although interaction of initial clinical severity of dementia was significant. Of 15 patients with these signs 3 (20%) died and 8 (53%) needed institutional care, while of 17 patients without these signs only 1 (6%) died and 2 (12%) were institutionalized by year 3 (p less than 0.01).