Clonidine and Gilles de la Tourette's syndrome: double-blind study using objective rating methods

Area of Science:

• Neurology
• Pharmacology

Background:

• Gilles de la Tourette syndrome (GTS) is a neurological disorder characterized by motor and vocal tics.
• Clonidine has been anecdotally suggested for GTS treatment, but lacked robust scientific validation.
• Objective evaluation of clonidine's efficacy in GTS was previously absent.

Purpose of the Study:

• To evaluate the effectiveness of clonidine in treating symptoms of Gilles de la Tourette syndrome.
• To assess clonidine's impact on motor tics, vocalizations, and overall behavior using objective measures.
• To compare different dosages and administration schedules of clonidine.

Main Methods:

• A 6-month, double-blind, placebo-controlled crossover study involving 30 patients with GTS.
• Objective assessment via randomized evaluation of videotaped tics (distribution, frequency, severity) and psychometric examinations.
• Comparison of low-dose (0.0075 mg/kg/day) versus high-dose (0.015 mg/kg/day) clonidine, and different dosing schedules (twice vs. three times daily).

Main Results:

• Clonidine treatment did not yield statistically significant reductions in motor tics, vocalizations, or behavioral symptoms (p < 0.05).
• No significant difference in efficacy was observed between low and high doses of clonidine.
• Patient age (children vs. adults) and concurrent neuroleptic use did not alter clonidine's lack of efficacy.
• Dosing frequency (twice daily vs. three times daily) did not impact objective tic ratings.

Conclusions:

• Clonidine demonstrated no significant efficacy in reducing the motor and vocal tics associated with Gilles de la Tourette syndrome.
• The study found no dose-dependent or schedule-dependent benefits of clonidine for GTS symptoms.
• Objective measures failed to support the use of clonidine as an effective treatment for GTS.