Which movement phenomenon is defined by sudden, rapid, recurrent, nonrhythmic movements including simple and complex motor and vocal tics?

• A. Tics
• B. Myoclonus
• C. Stereotypy
• D. Akathisia

Answer: (A)

Movement phenomena characterized by sudden, rapid, recurrent, nonrhythmic motor and vocal manifestations are tics. These can be simple motor tics like eye blinking or throat clearing or complex sequences that involve multiple muscles or phrases. The key features are their abrupt onset, brief, repetitive nature, and lack of a regular rhythm, and they often wax and wane in frequency and intensity. Tics can be temporarily suppressed with effort, though suppression frequently leads to a rebound. This contrasts with myoclonus, which are brief, shock-like muscle contractions; stereotypies, which are repetitive, rhythmic, patterned movements; and akathisia, which is an inner restlessness with a compelling urge to move, usually as a medication effect. Tics are the hallmark movement phenomenon often discussed in the context of Tourette syndrome when multiple motor tics and at least one vocal tic persist for more than a year.