A phase II, open-label, non-comparative study of Botulinum toxin in Restless Legs Syndrome.
OBJECTIVE
To assess the efficacy of intradermally injected botulinum neurotoxin type A (BoNT/A) in patients with Restless Legs Syndrome (RLS).


METHODS
We conducted an optimal two-stage, phase II exploratory, open label, non-comparative clinical trial. The primary outcome measure was the efficacy of BoNT/A defined by the proportion of patients (responders) with ⩾50% improvement of their RLS severity score at week 2 following injections compared to baseline score at inclusion. Twenty-seven patients were to be included in the first stage of the trial, which was to be stopped if less than nine responders were documented. Selected patients had a minimum score of 21 on the International RLS Rating Scale. They all received a series of 20 intradermal injections of 0.05 ml of BoNT/A in symptomatic areas in their lower limbs. Change of RLS severity was evaluated over a 6 months period.


RESULTS
Of the 27 selected patients, only six achieved the primary endpoint at week 2. In these six patients, the median duration (Inter-Quartile Range) of the IRLSRS score improvement of at least 50% was 46 days (42-126).


CONCLUSIONS
Considering the proportion of responders as the primary endpoint of this trial, BoNT/A showed no efficacy in alleviating RLS sensory symptoms.
Service des Explorations Fonctionnelles du Système Nerveux, Hôpital Pellegrin, Place Amélie Raba-Léon, Bordeaux cedex, France. imad.ghorayeb@u-bordeaux2.fr
Imad
I
Ghorayeb
Antoine
A
Bénard
Alexandre
A
Vivot
François
F
Tison
Pierre
P
Burbaud
D000368:Aged; D001905:Botulinum Toxins / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007271:Injections, Intradermal; D008297:Male; D008875:Middle Aged; D012148:Restless Legs Syndrome / Q000188:drug therapy*; D016896:Treatment Outcome
D001905:Botulinum Toxins