Therapy of intention myoclonus with L-5-hydroxytryptophan and a peripheral decarboxylase inhibitor, MK 486.
Three patients with postanoxic intention myoclonus, two patients with intention tremor, and one patient with cerebral palsy were administered L-5-hydroxytryptophan (L-5HTP), the precursor of serotonin, in combination with MK 486, a peripheral amino acid decarboxylase inhibitor. L-5HTP combined with MK 486 were potent long-term therapeutic agents for postanoxic intention myoclonus, but had no effect on intention tremor or cerebral palsy. These drugs were well-tolerated by the patients, and more effective than any other known therapy for intention myoclonus. Cerebrospinal fluid concentration of 5-hydroxyindoleacetic acid, the main catabolite of serotonin, appeared low in two patients with intention myoclonus and increased markedly during drug therapy. Postanoxic intention myoclonus may be causally related to a deficiency of brain serotonin.
D006916:5-Hydroxytryptophan / Q000008:administration & dosage / Q000627:therapeutic use*; D000293:Adolescent; D000328:Adult; D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D002230:Carbidopa / Q000008:administration & dosage / Q000627:therapeutic use*; D002547:Cerebral Palsy / Q000188:drug therapy; D004359:Drug Therapy, Combination; D005260:Female; D006719:Homovanillic Acid / Q000134:cerebrospinal fluid; D006801:Humans; D006834:Hydrazines / Q000627:therapeutic use*; D006897:Hydroxyindoleacetic Acid / Q000134:cerebrospinal fluid; D000860:Hypoxia / Q000150:complications; D008297:Male; D008784:Methysergide / Q000627:therapeutic use; D008875:Middle Aged; D009207:Myoclonus / Q000134:cerebrospinal fluid / Q000188:drug therapy* / Q000209:etiology; D011339:Probenecid / Q000134:cerebrospinal fluid / Q000627:therapeutic use; D012701:Serotonin / Q000378:metabolism / Q000502:physiology
D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D006834:Hydrazines; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D006916:5-Hydroxytryptophan; D002230:Carbidopa; D011339:Probenecid; D006719:Homovanillic Acid; D008784:Methysergide