The effect of amantadine on levodopa-induced dyskinesias in Parkinson's disease: A double-blind, placebo-controlled study

We performed a double-blind, placebo-controlled, crossover study to assess the effect of amantadine versus placebo on levodopa-induced dyskinesias in Parkinson's disease. We found a 24% reduction in the total dyskinesia score after amantadine administration (p = 0.004). This improvement was achievem ent without any influence on the severity of "on" period parkinsonism. The results confirm that amantadine reduces levodopa dyskinesias and support th e hypothesis that dyskinesias can be reduced by blockade of excitatory path ways in the basal ganglia.