Multiple sclerosis and restless legs syndrome: a systematic review and meta-analysis

Background and purpose Restless legs syndrome (RLS) has been reported to occur more frequently in patients with multiple sclerosis (MS) than in people without MS. Methods Systematic review and meta-analysis of studies investigating RLS in patients with MS published through April 2012. We calculated the prevalences and 95% confidence intervals (CIs) of RLS in patients with MS and people without MS as well as odds ratios (ORs) and 95% CIs of the association between MS and RLS based on data from the publications. We then calculated pooled effect estimates for the association between MS and RLS. Results We identified 24 studies. RLS prevalence amongst patients with MS ranged from 12.12% to 57.50% and from 2.56% to 18.33% amongst people without MS. Heterogeneity amongst studies was high (RLS prevalence in patients with MS I2=94.4%; RLS prevalence amongst people without MS I2=82.2%). Hence, we did not pool the prevalence data for meta-analysis. Heterogeneity amongst studies investigating the association between MS and RLS was moderate (I2=53.6%). Pooled analysis indicates that MS is associated with a fourfold increased odds for RLS (pooled OR=4.19, 95% CI 3.115.66). This association was smaller amongst studies published as full papers (pooled OR=3.94, 95% CI 2.815.54) than amongst studies published as abstracts only (pooled OR=6.23, 95% CI 3.2511.95). Conclusion This systematic review indicates that RLS prevalence amongst patients with MS ranges from 12.12% to 57.50% in different populations. Pooled analysis further indicates that the odds of RLS amongst patients with MS are fourfold higher compared to people without MS.