Tourette syndrome and other tic disorders. Diagnosis, pathophysiology, and treatment

In this report, we discuss the definition, characteristics, pathophysiology, and treatment of tic disorders with a major emphasis on Tourette syndrome. Although the diagnosis of a tic disorder depends on the presence of motor and/or phonic tic(s), patients with these problems also have a variety of co-morbid features including obsessive-compulsive symptoms, attention-deficit hyperactivity disorder, behavioral difficulties, and learning disabilities. Conservative estimates for Tourette syndrome suggest a prevalence rate of 0.1-1.0 per 1000. This syndrome is inherited in a sex-influenced autosomal dominant pattern with either chronic multiple tic disorder or obsessive-compulsive disorder as alternative phenotypes of the putative gene. Current evidence continues to support a pathophysiologic mechanism involving synaptic neurotransmission, with the dopaminergic system as a primary candidate. Therapeutically, it is essential to clarify whether a patient's problems are related to tics or associated behavioral difficulties. Pharmacotherapy for motor and phonic tics is strictly symptomatic and should be reserved for those with functionally disabling symptoms. A comprehensive individualized treatment program is often required in the care of individuals with tic disorders.