title: Improvement in freezing phenomenon of Parkinson's disease after DL-threo-3, 4-dihydroxyphenylserine.
abstract: A 77-year-old man with Parkinson's disease of long standing, under treatment with L-DOPA and benserazide, was administered DL-threo-3, 4-dihydroxyphenylserine (DL-threo-DOPS), a precursor of norepinephrine, for 10 days. With this administration the patient's freezing phenomenon was remarkably improved, and his dysarthria also showed improvement. When DL-threo-DOPS was suspended, the frozen gait returned on the third day to almost the former level, even though he continued to receive L-DOPA and benserazide. After administration of DL-threo-DOPS, the CSF level of 3-methoxy-4-hydroxyphenylglycol (MHPG), a major metabolite of norepinephrine, was 127.5% of the pretreatment level. These observations suggest that DL-threo-DOPS can pass through the blood-brain barrier and change to norepinephrine, and that DL-threo-DOPS may be beneficial in the treatment of the freezing phenomenon of Parkinson's disease.
mesh_terms: D000368:Aged; D001545:Benserazide / Q000627:therapeutic use; D015103:Droxidopa / Q000627:therapeutic use*; D005684:Gait; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000134:cerebrospinal fluid; D010300:Parkinson Disease / Q000188:drug therapy*; D012694:Serine / Q000031:analogs & derivatives*
chemical_list: D012694:Serine; D007980:Levodopa; D008734:Methoxyhydroxyphenylglycol; D001545:Benserazide; D015103:Droxidopa