CONTROLLED TRIAL OF 5-HYDROXY-L-TRYPTOPHAN FOR ATAXIA IN PROGRESSIVE MYOCLONUS EPILEPSY

To study the role of serotonin in the ataxia of progressive myoclonus epilepsy, eight patients received oral 5-hydroxy-L-tryptophan (L-5-HTP ) or placebo plus carbidopa for 1 month in a controlled, double-blinde d, dose-ranging, cross-over, add-on study. Ataxia was evaluated using objective and subjective scales. All of the subjects had significantly slower motor performance on timed, repetitive tasks than controls and had moderately severe ataxia. L-5-HTP was not efficacious for ataxia or speed of motor performance. Serotonergic drugs that work through me chanisms different than L-5-HTP may be more effective in correcting th e abnormal serotonergic neurotransmission suggested by reduction of se rotonin metabolites in cerebrospinal fluid in patients with progressiv e myoclonus epilepsy.