Restless Leg Syndrome in Individuals with Multiple Sclerosis: Effects on Disability and Perceived Physical Health

Background: Restless Leg Syndrome (RLS) is significantly more prevalent in the multiple sclerosis (MS) population than in healthy controls. Studies exploring the relationship between RLS and MS have found conflicting results. According to a recent systemic review and meta-analysis, approximately half of such studies report increased disability in patients with RLS, and approximately half have found no such correlation.

Objectives: Elucidate the relationship, in MS patients, between RLS and quality of life, MS-related disability, and perception of degree of disability.

Methods: This is a cross-sectional study of 198 MS patients at Duke Hospital. Patients completed a survey including demographic data, information on comorbidities such as RLS, and the following self-reported measures of clinical outcome: employment status, physical and mental quality of life (QOL) collected using SF-12, and patient-reported disability collected using the Patient Determined Disease Steps (PDDS). We separately examined RLS’s effects on two broad categories of motor disability: mobility and fine motor function.

Results: Of the 198 MS patients studied, 39 (20%) reported suffering from RLS. Within our cohort of MS patients, we found no significant association between RLS and patient-reported disability (Z = -1.060708, p = 0.2888), mobility (Z= -1.206974, p=0.2274), employment status (full time, part time, unemployed) X² (2, N = 153) = 2.6282, p = 0.2687, physical QOL (Z = -1.823465, p = 0.06823), and mental QOL (Z = -0.1341077, p = 0.8933). We did find a significant association between RLS and fine motor function, with RLS (+) patients reporting increased fine motor impairment (Z=-2.262894, p=0.02364). Patients with RLS also had a worse perception of their own physical health, being more likely to report having accomplished less than they would like and/or being limited in their work or other activities due to physical health (Z = -2.359767, p = 0.01829).

Conclusions: RLS does not impact QOL, employment rate, patient-reported disability, or mobility in the MS population. However, RLS may negatively impact fine motor function in MS patients as well as patients’ perceptions of their own physical health and limitations. The implication for patient care is as follows. Given RLS’s prevalence in the MS population, and the fact that as per prior studies, more than a third of MS patients with RLS symptoms do not report their struggles with RLS to their neurologist, the impact of RLS on fine motor function and health perceptions suggests that MS patients may benefit from being screened for RLS and offered treatment if symptoms are reported.