Amantadine for levodopa-induced choreic dyskinesia in compound heterozygotes for GCH1 mutations

Amantadine suppressed severe levodopa-induced choreic dyskinesia, which developed at initiation of levodopa therapy, in two siblings manifesting dystonia with motor delay phenotype of GTP cyclohydrolase 1 deficiency caused by compound heterozygous GCH1 mutations. Our finding suggests a beneficial effect of amantadine on this type of dyskinesia frequently observed in relatively severe dopamine-deficient metabolic disorders. (C) 2004 Movement Disorder Society.