Which movement phenomenon includes repetitive, patterned, rhythmic and complex involuntary motions seen in autism and Rett syndrome?

• A. Tics
• B. Myoclonus
• C. Stereotypy
• D. Tourette disorder

Answer: (C)

Stereotypy refers to repetitive, patterned, rhythmic motor (and sometimes vocal) behaviors that are involuntary and nonfunctional. In autism and Rett syndrome, these movements are characteristic and often persistent, such as hand-flapping, body rocking, spinning, or hand-wringing in Rett. They contrast with tics, which are sudden, rapid, nonrhythmic movements or sounds that can be preceded by a compelling urge and are more typical of tic disorders like Tourette. Myoclonus involves brief, shock-like jerks, not sustained, rhythmic patterns. Tourette disorder centers on multiple motor and vocal tics lasting more than a year, rather than the persistent, patterned rhythms seen in stereotypy. Because the question emphasizes the repetitive, patterned, rhythmic involuntary motions seen in autism and Rett, stereotypy is the best descriptor.