Effect of L-tryptophan on spasmodic torticollis.
The effect of L-tryptophan, a precursor of serotonin, and placebo were studied in eight patients with spasmodic torticollis. L-Tryptophan (5 g po as a single dose) which increased free plasma tryptophan 20-53 fold improved only one out of six patients. Two out of three patients, including the subject who improved following an oral load of tryptophan, improved with L-tryptophan combined with nicotinamide, a tryptophan pyrrolase inhibitor, when administered for 1-3 weeks. However, the magnitude of clinical improvement was not impressive. Our findings suggest that impairment of serotonergic function is not a general finding in spasmodic torticollis though it may play a minor role in the manifestation of this movement disorder in some patients. The present study emphasizes therapeutic response, namely, the intrinsic variability of the disorder, the response to placebo in some subjects and the limitations of methods for measuring change.
D004359:Drug Therapy, Combination; D006801:Humans; D009068:Movement; D009536:Niacinamide / Q000627:therapeutic use; D014103:Torticollis / Q000188:drug therapy* / Q000503:physiopathology; D014364:Tryptophan / Q000627:therapeutic use*
D009536:Niacinamide; D014364:Tryptophan