Double-blind crossover study with dolasetron mesilate, a 5-HT3 receptor antagonist in cerebellar syndrome secondary...

Cerebellar syndrome is one of the most disabling developments in multiple sclerosis (MS). In neurodegenerative disorders, cerebellar syndrome is thought to be related to a neurochemical deficit of 5-hydroxytryptamine (5-HT). Previous studies found that a levorotatory form of 5-hydroxytryptophan, a 5-HT precursor, and ondansetron, a 5-HT(3) receptor antagonist, decreased cerebellar symptoms in Friedreich's ataxia and MS. We studied the effect of another 5-HT(3) receptor antagonist, dolasetron mesilate, on cerebellar syndrome in MS patients.Thirty-four MS patients were included in a placebo-controlled double-blind crossover study. They received a single dose of intravenous dolasetron mesilate or placebo. A quantitative evaluation of cerebellar syndrome using the nine-hole peg test and an ataxia score comprising static and kinetic parameters were performed before and after each treatment. No statistical difference was observed in the dolasetron mesilate group, compared with the placebo group. There was, however, inter-individual variability in the treatment response. This double-blind study on cerebellar syndrome in MS patients did not confirm the positive effect of dolasetron mesilate suggested by previous studies.