Prevalence of restless legs syndrome and REM sleep behavior disorder in multiple sclerosis

A total of 135 consecutive, unrelated, multiple sclerosis (MS) patients were interviewed for symptoms suggestive of restless legs syndrome (RLS) and REM sleep behavior disorder (RBD), using semi-structured questionnaires. Some 118 unrelated healthy controls of similar sex and age distribution were included for comparison. Patients and controls with equivocal symptoms were re-evaluated by a sleep disorders specialist and video-polisomnography in those who fulfilled the criteria for RBD. We did not find significant differences in frequency (13.3 versus 9.3%), proportion of females (66.7 versus 58.5%), and mean age (42.1 +/- 12.6 versus 43 +/- 7.8 years) among MS patients and controls with RLS. RBD was found in three patients (1.4%), one associated with antidepressant intake, but in none of the controls. Our study shows that RLS in MS is not more frequent than in the general population, and that RBD, although uncommon, may occur in the setting of this neurological disease.