Antiepileptic drugs and Tourette syndrome

Tourette syndrome is a neurodevelopmental disorder characterized by the chronic presence of multiple motor tics and at least one vocal/phonic tic for the duration of 1 year. The clinical picture of patients with Tourette syndrome is often complicated by tic-related behavioral problems and associated psychopathology. The pathophysiology of Tourette syndrome is not thoroughly understood, however converging evidence from neuroimaging studies suggests abnormalities within the frontostriatal pathways which are mediated by several neurotransmitters. The pharmacological management of the tic symptoms focuses on the dopaminergic and noradrenergic pathways and aims to improve the health-related quality of life of patients. The most common medications are neuroleptics and atypical antipsychotics, which have a strong D2 blocking action. Also, preliminary studies have documented the efficacy of antiepileptic drugs in controlling tics. Thus far, two anticonvulsants (topiramate and levetiracetam) have been tested with a randomized, double-blind, placebo-controlled procedure in the treatment of tics. A study has reported an improvement in the control of tics with topiramate. This pharmacological agent was also reported to be well tolerated by the patients. However, the most frequent observed topiramate side effects (such as somnolence, cognitive problems, and weight loss) could not have manifested because of the short trial duration. Levetiracetam has shown conflicting results. A study found significant improvements in the control of tics, also associated with improvement in school performance. These results, however, were not replicated in other studies. Further investigations are therefore needed to assess the real efficacy of antiepileptic drugs in the treatment of tics.