Parkinsonian signs and functional disability in old age.

Little is known about the association between parkinsonian signs and functional disability. The authors examined the associations between four parkinsonian signs (gait, rigidity, bradykinesia, tremor) and the ability to perform physical and instrumental activities of daily living, in a large cohort of older Rush Memory and Aging Project participants who were free of dementia, Parkinson's disease, and antipsychotic drug use. In a series of logistic regression equations that controlled for age, sex, education, depressive symptoms, cognitive ability, chronic medical conditions, and psychotropic drug use, higher levels of parkinsonian signs were associated with higher levels of disability in performing both physical and instrumental activities of daily living.