[Identification of restless legs syndrome in polysomnography studies and its association with other variables]

Restless legs syndrome (RLS) is a movement disorder characterized by an uncontrollable urge to move the legs in response to an unpleasant sensation. The coexistence of RLS and other sleep and mood disorders may require adjustment in the therapeutic strategy. The objective of this study was to determine the prevalence of RLS in adults studied with polysomnography and to evaluate its association with other sleep and mood disorders.

Descriptive cross-sectional study. We included adults studied with polysomnography between 2015 and 2021. We collected information on their medical history, polysomnographic data and mood and sleep disorders using a self-administered written questionnaire which is part of the routine evaluation of all patients referred to this sleep unit. These variables were compared between patients with and without RLS.

We included 406 patients. The prevalence of RLS was 36.7% (n = 149). The presence of fatigue (45.3%), moderate to severe insomnia (38.9%) and depression (45.6%) was higher in subjects with RLS. We did not find differences regarding daytime sleepiness and anxiety symptoms. Periodic Limb Movements (PLM) was not associated with RLS (p = 0.26) and its prevalence was low.

The prevalence of RLS in subjects studied with Polysomnography is high and it was associated with clinically significant fatigue, insomnia and depression. These symptoms should be identified in order to establish an adequate therapeutic strategy. The prevalence of periodic limb movements was low and was not linked with RLS. These findings contrast with previous publications. Therefore, it requires additional studies to clarify the cause of this variation.