[Onset-and end-of-dose dyskinesias induced by L-dopa treatment in a patient with juvenile parkinsonism].

A 33-year-old male with diphasic dyskinesia was presented. He began to have difficulty with walking at the age of 27, and was diagnosed to have juvenile parkinsonism. For the past two years, L-dopa has been prescribed with good initial response. One year ago peripheral dopa decarboxylase inhibitor in combination with L-dopa was started, and he began to have involuntary movements. One hour after taking 2 tablets of EC dopa (L-dopa 100 mg + benserazide 25 mg), violent involuntary ballistic movements appeared in all four extremities which lasted for 15 minutes. For the following 50 minutes, his symptoms of parkinsonism markedly improved. The score of parkinsonism reduced by 58%, and he was able to walk. The plasma dopa level was increasing during this period. However, during decreasing period of plasma dopa concentration, he did not have end-of-dose dyskinesia. On the other hand, one hour after taking 500 mg of L-dopa involuntary choreic movements appeared in his right upper extremity for several minutes without any improvement of parkinsonism. Three hours and 20 minutes after taking L-dopa, he developed mild choreic movements for several minutes followed by marked improvement of parkinsonism for 30 minutes. The score of parkinsonism reduced by 79%. Thirty minutes later, he developed violent ballistic movements in all four extremities, lasting for 30 minutes followed by reappearance of parkinsonism. The concentration of plasma dopa was decreasing during this period.(ABSTRACT TRUNCATED AT 250 WORDS)