Restless legs syndrome as a comorbidity in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a multisystem disease with a complex immunologic pathophysiology. Likewise, sleep disorders can involve a complicated interplay between the neurologic pathways, immune system, and respiratory system. Recent studies have shown an elevated prevalence of sleep abnormalities in connective tissue disorders compared to the general population. Restless legs syndrome (RLS) may be present in up to 30% of RA patients. These findings may be related to cytokine release and other immunomodulatory responses. TNF- α levels relate to sleep physiology and anti-TNF- α therapy may improve sleep patterns. Most of the patients with this disorder can distinguish their RLS sensations from their arthritic symptoms. RLS is a common comorbidity seen with RA, and prompt recognition and treatment can improve patient quality of life.