Clinical symptomatology, CSF neurotransmitter metabolites, and serum haloperidol levels in Tourette syndrome.

Our studies have demonstrated that TS patients show a high degree of sensitivity to butyrophenone blockade of dopaminergic receptors. The clinical response to extremely low serum levels of haloperidol includes sedating side effects, as well as therapeutic effects. These clinical changes are associated with significant increases in CSF HVA levels, which were abnormally decreased before treatment. CSF HIAA levels tended to be normal and did not change with haloperidol treatment. These results lend additional support to the hypothesis that TS is related to supersensitivity of dopaminergic receptors.