Manipulation of brain serotonin in the treatment of myoclonus.
The response of myoclonus to oral and intravenous L-5-hydroxytryptophan (5-H.T.P.) in combination with a peripheral decarboxylase inhibitor (carbidopa) and to clonazepam has been examined in 9 patients. Moderate improvement or complete cessation of myoclonus followed treatment with one or both of these regimens in 5 patients, 1 of whom also responded to the concurrent administration of L-tryptophan and a monoamineoxidase inhibitor. The remaining 4 patients were at best only slightly improved by either 5-H.T.P. or clonazepam. The responsive group consisted of 3 patients with a history of anoxia, 1 patient with non-history of severe head injury, and 1 patient with non-progressive focal myoclonus and epilepsy. This group had low levels of 5-hydroxyindole acetic acid in the lumbar cerebrospinal fluid. It is suggested that 5-H.T.P. plus carbidopa, L-tryptophan plus a monoamine-oxidase inhibitor, and clonazepam may all act by elevating brain levels of serotonin (5-H.T.) and that some human myoclonic syndromes may be specifically related to a cerebral deficiency of 5-H.T.
D006916:5-Hydroxytryptophan / Q000008:administration & dosage / Q000627:therapeutic use; D000284:Administration, Oral; D000328:Adult; D000368:Aged; D001570:Benzodiazepinones / Q000627:therapeutic use*; D001921:Brain / Q000378:metabolism*; D002230:Carbidopa / Q000008:administration & dosage / Q000627:therapeutic use*; D002998:Clonazepam / Q000008:administration & dosage / Q000627:therapeutic use*; D004341:Drug Evaluation; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006834:Hydrazines / Q000627:therapeutic use*; D007263:Infusions, Parenteral; D008297:Male; D008875:Middle Aged; D009207:Myoclonus / Q000188:drug therapy* / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism*
D001570:Benzodiazepinones; D006834:Hydrazines; D012701:Serotonin; D002998:Clonazepam; D006916:5-Hydroxytryptophan; D002230:Carbidopa