Serotonin and myoclonus.
Biochemical studies of serotonin metabolism and a therapeutic trial of L-5-hydroxytryptophan (L-5-HTP) in combination with carbidopa were carried out in 19 patients with myoclonus. In 6 patients with intention myoclonus, the cerebrospinal fluid concentration of 5-hydroxyindoleacetic acid, a metabolite of serotonin was found to be significantly decreased. L-5-HTP with carbidopa dramatically decreased the frequency and intensity of myoclonus, particularly in those patients with a diagnosis of postanoxic intention myoclonus. The major side effects have been anorexia, nausea, vomiting, diarrhea and mental stimulation. We suggest that a deficiency of brain serotonin is causally related to myoclonic muscle movements and the therapeutic efficacy of L-5-HTP plus carbidopa may be due to the repletion of serotonin in regions of the brain where serotoninergic neurons have degenerated.
D006916:5-Hydroxytryptophan / Q000009:adverse effects / Q000627:therapeutic use; D000293:Adolescent; D000328:Adult; D002230:Carbidopa / Q000009:adverse effects / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D004827:Epilepsy / Q000188:drug therapy / Q000378:metabolism; D005260:Female; D006719:Homovanillic Acid / Q000134:cerebrospinal fluid; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000134:cerebrospinal fluid; D007211:Indoles / Q000134:cerebrospinal fluid; D008297:Male; D008875:Middle Aged; D009207:Myoclonus / Q000188:drug therapy / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*
D007211:Indoles; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D006916:5-Hydroxytryptophan; D002230:Carbidopa; D006719:Homovanillic Acid