[High prevalence of restless legs syndrome in multiple sclerosis]

Prevalence of restless legs syndrome (RLS), a clinically defined disorder, varies from 2.5 to 15% among populations. In the French adult population, prevalence is estimated to be 8.5%. RLS is often secondary to a variety of disorders. Neurological conditions usually associated with RLS are neuropathies and Parkinson's disease. There are few studies of its association with multiple sclerosis (MS). The aim of this study was to estimate RLS prevalence in a population of French MS patients. During one month, 17 neurologists from the G-SEP group prospectively recruited 242 patients who fulfilled the Mc Donald criteria for MS. Each patient underwent a standardised questionnaire to verify the international criteria of RLS. We collected date of birth, gender, MS course (relapsing remitting, primary progressive and secondary progressive) and MS duration. Forty-one subjects (18%) met the criteria for RLS. Comparing the RLS group with the group without RLS, no significant differences were found in age, gender and MS duration. RLS was more prevalent in the relapsing remitting MS group. Prevalence of RLS seems to be doubled in MS patients compared to the general population. This finding warrants further study. Identification of this syndrome in MS patients might lead to specific treatments.