Migraine and restless legs syndrome: a systematic review.

BACKGROUND: Restless legs syndrome (RLS) is increasingly being reported as a comorbidity of migraine.
METHODS: We conducted a systematic review and meta-analysis of studies investigating RLS in headache/migraine and vice versa. We calculated the prevalence and 95% confidence intervals (CI) of RLS in headache/migraine, of headache/migraine in RLS and controls, and odds ratios (ORs) of the association between the conditions. We then determined pooled effect estimates for the associations.
RESULTS: We identified 24 studies. RLS prevalence in migraine ranged from 8.7% to 39.0% with no apparent differences based on gender and aura status. Prevalence among controls was compatible with the literature. Migraine prevalence in RLS ranged from 15.1% to 62.6%. We did not pool prevalence data because of high unexplained heterogeneity. High heterogeneity with respect to the association between any migraine and RLS could be explained by study design. Pooled analyses showed substantially higher effect estimates in case-control studies (pooled OR = 4.19, 95% CI 3.07-5.71; I (2) = 0.0%) than in cohort studies (pooled OR = 1.22, 95% CI 1.14-1.30; I (2) = 0.0%).
CONCLUSION: Our results support the concept of RLS as an important comorbidity of migraine. However, the degree of association appears to be strongly determined by study design. Potential effects by gender and aura status and the role of RLS in other headache disorders remain unclear. © International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.