Hyperkinetic Movement Disorders: Chorea, Tic, and Dystonia

Abstract Hyperkinetic movement disorders are characterized by an excess of movement. This chapter outlines the classification, causes, and treatment of chorea, tic disorders, and dystonia. The term chorea refers to dancelike irregular, arrhythmic, rapid, involuntary movements that appear to flow between muscle groups. Athetosis, a slower and twisting dystonialike movement, may be superimposed with chorea, leading to choreoathetosis. Ballism is a form of high-amplitude and proximal chorea that has the appearance of flailing movement.