Anticholinergic challenge and cognitive functions: a comparison between young and elderly normal subjects.

Challenges of the central cholinergic function with anticholinergic agents have been shown to produce disruption of cognitive performance in young normal people. The purpose of the study was to compare the effects of a low dose of scopolamine in young and elderly subjects and to determine which cognitive functions are most sensitive to disruption by anticholinergics in an elderly population. Scopolamine (0.2 mg) and placebo were given to 12 normal elderly subjects (mean age 64.1 years) and 14 young subjects (mean age 26.7 years) and neuropsychological tests were designed to measure the functions of verbal memory, praxis and language. Scopolamine significantly impaired new learning in the elderly as measured by Selective Reminding Test (SRT) (p less than 0.04) and SRT delayed recall (p less than 0.05), but had no effect in the young subjects. Following the anticholinergic challenge, the elderly people also showed significantly poorer performance in all tests used for the praxis function. Results suggest a role of the cholinergic neurotransmission in verbal memory and constructional praxis. The language function was not impaired in the elderly and is not affected by anticholinergic agents.