Tourette syndrome: evolving concepts.

Tourette syndrome is a common childhood-onset neurobehavioral disorder characterized by multiple motor and phonic tics affecting boys more frequently than girls. Premonitory sensory urges prior to tic execution are common, and this phenomenon helps to distinguish tics from other hyperkinetic movement disorders. Tourette syndrome is commonly associated with attention deficit hyperactivity disorder, obsessive-compulsive disorder, learning difficulties, and impulse control disorder. The pathophysiology of this complex disorder is not well understood. Involvement of basal ganglia-related circuits and dopaminergic system has been suggested by various imaging and postmortem studies. Although it is considered a genetic disorder, possibly modified by environmental factors, an intense search has thus far failed to find causative genes. Symptomatic treatment of tics chiefly utilizes various alpha adrenergic agonists, antidopaminergic drugs, topiramate, botulinum toxin, and deep brain stimulation. Habit reversal therapy and other behavioral approaches may be a reasonable option for some cases. Improved understanding of Tourette syndrome should lead to better symptomatic and more effective pathogenesis-targeted therapies.