Extrapyramidal signs and cognitive abilities in Alzheimer's disease

Objective To evaluate whether the relationship between extrapyramidal signs (EPS) and cognitive disturbances in Alzheimer's disease (AD) is influenced by illness duration. Methods A multivariate regression analysis was used to study the relationsh ips between EPS, illness duration and five cognitive ability areas based on the Mattis Dementia Rating Scale (DRS) in 89 clinically diagnosed AD patie nts with extrapyramidal motor involvement. Results Severity of EPS was statistically associated with performance on fo ur cognitive ability areas from the DRS including: attention, initiation an d perseveration, construction and memory. Age was a significant factor rela ted to severity of EPS. However illness duration did not contribute to the strength of the association between EPS and cognitive disturbances in patie nts with AD. Conclusions The findings of the present study support the notion that while neuropsychological and motor functions often coexist in patients with AD, their relationship seems to be unrelated to degenerative processes that acc umulate throughout the illness. Copyright (C) 2001 John Wiley & Sons, Ltd.