Tourette's syndrome.

Tourette's syndrome is a movement disorder most commonly seen in school-age children. The incidence peaks around preadolescence with one half of cases resolving in early adulthood. Tourette's syndrome is the most common cause of tics, which are involuntary or semivoluntary, sudden, brief, intermittent, repetitive movements (motor tics) or sounds (phonic tics). It is often associated with psychiatric comorbidities, mainly attention-deficit/hyperactivity disorder and obsessive-compulsive disorder. Given its diverse presentation, Tourette's syndrome can mimic many hyperkinetic disorders, making the diagnosis challenging at times. The etiology of this syndrome is thought to be related to basal ganglia dysfunction. Treatment can be behavioral, pharmacologic, or surgical, and is dictated by the most incapacitating symptoms. Alpha2-adrenergic agonists are the first line of pharmacologic therapy, but dopamine-receptor-blocking drugs are required for multiple, complex tics. Dopamine-receptor-blocking drugs are associated with potential side effects including sedation, weight gain, acute dystonic reactions, and tardive dyskinesia. Appropriate diagnosis and treatment can substantially improve quality of life and psychosocial functioning in affected children.