Olanzapine in severe Gilles de la Tourette syndrome: a 52-week double-blind cross-over study vs. low-dose pimozide.

We selected four patients with severe Gilles de la Tourette syndrome, high frequency of tics (two to ten per minute), vocalizations, and lack of comorbidity. These patients (aged 19-40 years) underwent a 52-week double-blind cross-over study with olanzapine (5 and 10 mg daily) vs. low-dose pimozide (2 and 4 mg daily). The reduction in rating scale scores for the syndrome was highly significant with 10 mg olanzapine vs. basal and vs. 2 mg pimozide, and was significant for 5 mg olanzapine vs. 4 mg pimozide. Only moderate sedation was reported by one patient during olanzapine treatment while three complained of minor motor side effects and sedation during pimozide treatment. At the end of the study all patients opted for olanzapine treatment.