Tics are defined as sudden, rapid, and repeating muscle movements often associated with vocalizations.

Tics occur in a wide variety of disorders. Transient tic disorders occur in up to 25% of children—most commonly in boys. Typically, tics do not occur during sleep and can be controlled voluntarily for short periods of time. Stress and fatigue can make these tics worse.

Eventually, most tics disappear spontaneously. However, in fewer than 1% of children, tics persist. Such tics may lead to a diagnosis of Tourette's syndrome (see Neurologic Disorders in Children: Tourette's Syndrome), or they may be associated with obsessive-compulsive disorder, some infections, or certain drugs (eg, stimulants).

Usually, no treatment is required. If tics persist and are bothersome (eg, as in Tourette's syndrome), drugs may be used.

Last full review/revision April 2009 by Hugh F. Johnston, MD