Blood choline and response to clonazepam and haloperidol in Tourette's syndrome.

This paper reports the results of a single blind clinical study of drug treatment response of 20 patients with Tourette's syndrome to haloperidol and clonazepam. Because patients with Tourette's syndrome have been reported to have increased red blood cell choline levels, choline levels were examined in relation to treatment response. Differential drug treatment response was found among patients with high versus low red blood cell-to-plasma choline ratios. Patients with high red blood cell-to-plasma choline ratios responded better to clonazepam than to haloperidol. This suggests that there may be two distinct subtypes of patients with Tourette's syndrome.