Double-blind crossover study with levorotatory form of hydroxytryptophan in patients with degenerative cerebellar diseases
K. Wessel, J. Hermsdorfer, K. Deger, T. Herzog, G. P. Huss, D. Kompf, N. Mai, K. Schimrigk, A. Wittkamper and W. Ziegler
Department of Neurology, Medical University of Lubeck, Germany.
OBJECTIVE: To determine whether treatment with the levorotatory form of
hydroxytryptophan (L-5-hydroxytryptophan), a controversial experimental
drug, can improve the conditions of patients with ataxia. DESIGN: A
double-blind crossover study with the levorotatory form of
hydroxytryptophan was performed in 39 patients with degenerative cerebellar
diseases. SETTING: Patients were selected from an ongoing prospective
follow-up study at two university hospitals. PATIENTS: We studied 19
patients with Friedreich's ataxia, 13 with cerebellar atrophy, and seven
with olivoponto-cerebellar atrophy. INTERVENTION: The levorotatory form of
hydroxytryptophan was given orally in a dose of 1000 mg/d. Each treatment
phase, with the levorotatory form of hydroxytryptophan or the placebo,
lasted 10 months, after which the treatment of patients was crossed over to
the other phase. MAIN OUTCOME MEASURES: Ataxia was documented and
quantified by using a clinical score, posturography, and measurement of
grip force and the rapid-syllable repetition rate. RESULT: The levorotatory
form of hydroxytryptophan had no significant effect on cerebellar symptoms.
CONCLUSION: Long-term treatment with a high dose of the levorotatory form
of hydroxytryptophan does not improve the conditions of patients with
ataxia.