Timing recalibration in childhood Tourette syndrome associated with persistent pimozide treatment.

In this study, we have tested the effects of the dopamine D2 receptor blocker pimozide on timing performance in patients with Tourette syndrome (TS). Nine children with TS were tested off-medication and following 3 months of daily treatment with pimozide. Subjects completed a time reproduction and a time production task using supra-second temporal intervals. We show that pimozide improves motor timing performance by reducing the patients' variability in reproducing the duration of visual stimuli. On the other hand, this medication has no effect on the reproduction accuracy and on both variability and accuracy of the performance on the time production task. Our results suggest that pimozide might have improved motor timing variability as a result of its beneficial side effect on endogenous dopamine levels (i.e., normalization).