Extrapyramidal examinations in psychiatry.

Extrapyramidal signs include increased motor tone, changes in the amount and velocity of movement, and involuntary motor activity. They include two groups of signs and related disorders: hypokinetic (similar to Parkinson's disease) and hyperkinetic (similar to Huntington's disease). This article covers some of the neuroscience behind extrapyramidal disorders, the relevance of extrapyramidal signs in the major psychiatric disorders, the major extrapyramidal movement disorders, and how to elicit extrapyramidal signs.