Intellectual disability as a comorbidity in Tourette syndrome: a case report.

As many as 86-90% of patients with Tourette syndrome have at least one comorbid condition or coexisting neuropsychological problems. Tourette syndrome is diagnosed on the basis of physical symptoms, especially the presence of multiple motor and vocal tics that began before the person was 21 years old. The diagnosis must also be supported by the presence of a comorbid behavioral disorder.