The Gilles de la Tourette syndrome.

The Gilles de la Tourette syndrome is a neuropsychiatric condition characterized by waxing and waning tics, both vocal and motor, over a lifelong course with an onset under the age of 21 years. Once considered a rare curiosity, its prevalence is now agreed to be around 5/10,000, and is seen worldwide. Many cases are mild and never require medical attention. It is now thought to have a genetic basis, but linkage has not yet been achieved, owing possibly to the inadequacy of a single-gene hypothesis. There is a strong association with obsessive compulsive disorder, and some postulate that many other psychiatric conditions may be determined as variations of the same phenotype. Attention deficit hyperactivity disorder is also common among sufferers. Management is with a combination of psychosocial measures and drugs; in particular dopamine antagonists, the efficacy of which has led to the theory that the syndrome is caused by an abnormality of the dopaminergic system. Studies using functional imaging techniques have both supported and rejected this hypothesis. Future research is expected to concentrate on the further application of genetic and brain imaging techniques in addition to clinical trials to identify optimal treatments. Studies relating to clinical, genetic, etiological, and historical aspects are reviewed.