Crohnʼs Disease Is Associated with Restless Legs Syndrome

Abstract

Purpose: Extraintestinal manifestations of Crohn's disease (CD) rarely include the central nervous system (CNS). Restless legs syndrome (RLS) is a CNS disorder that is either idiopathic or secondary to a number of diseases. RLS is the strong urge to move the legs often with discomfort, occurs in 10% of the population, and causes poor sleep and reduced quality of life. The aim of this study was to determine if CD was associated with RLS since both are associated with iron deficiency. Inflammation and bacterial overgrowth are also associated with RLS and occur commonly in pts with CD. Methods: All consecutive CD outpatients (F-151, M-121; mean age 43.8 yrs) were prospectively surveyed by gastroenterologists at Specialists in Gastroenterology, a community GI practice (N = 135), Weill Cornell Medical Center (N = 71), Washington University School of Medicine (N = 54), and Johns Hopkins School of Medicine (N = 12). No patients were excluded or refused the survey. All four international criteria were required to be positive for RLS: 1) urge to move legs often with discomfort, 2) worse at rest, 3) worsening at night, and 4) relief with activity. Incidence (having RLS at any point in time), prevalence (having RLS at time of survey), clinical characteristics, RLS risk factors, and potential qualitative relationship to GI symptoms were queried. One IRB limited the RLS frequency question to prevalence and did not allow RLS risk factor questions (54 of 272 surveys). Results: RLS incidence was 42.7% (93/218). Prevalence of RLS was 30.2% (82/272; CI 29.9–30.3%) vs. 8.7% (17/194; CI 8.6–8.8%) of spouses (P < 0.0001; odds ratio = 4.5; CI 2.54–7.87%). In 91.8% pts, RLS started during or after onset of diagnosis of CD. Among 72 RLS (+) pts, 44.5% stated there was correlation of qualitative RLS symptom improvement with overall CD symptom improvement. RLS (+) pts and RLS (−) CD pts had: mean age of 46.8 vs. 42.6 yrs, small intestine involvement in 77.9% vs. 66.7%, colon involvement in 39.7% vs. 63.2%, and prior iron deficiency anemia in 49.3% vs. 33.1%. There was no difference between the CD groups with respect to: gender ratio, current iron deficiency (4.6%), RLS family history (12%), or the rare prevalence of concomitant RLS disorders. Conclusion: RLS occurs frequently in CD and appears to be a new extraintestinal manifestation. Factors other than iron deficiency play a role in RLS pathophysiology in CD. The potential relationship of RLS with CD activity needs further investigation. Determination of the effect of RLS on the quality of life in CD is warranted.