Screening autonomic functions in patients with restless legs syndrome: A case-control study in a tertiary care hospital

Purpose: The clinical importance of autonomic involvement in patients with restless legs syndrome (RLS) remains unclear. To our knowledge, no study has explored the relationship between autonomic dysfunction and diseaserelated variables in patients with RLS. Therefore, this study aimed 1) to determine the presence of autonomic symptoms in drug-naive patients with RLS in comparison with healthy controls using Scales for Outcomes in Parkinson's disease-Autonomic (SCOPA-AUT) questionnaire and 2) to evaluate the possible associations of autonomic dysfunction with clinical factors in RLS. Methods: A total of 70 drug-naive patients with RLS and 85 healthy volunteers were enrolled. The SCOPA-AUT questionnaire and Epworth Sleepiness Scale (ESS) scores were used to determine autonomic functions and sleep propensity, respectively. Moreover, the International Restless Legs Syndrome Study Group rating scale was used to evaluate disease severity in the patient group. Results: Compared with the control group, the RLS group had significantly higher subscale scores (gastrointestinal, urinary, cardiovascular, thermoregulatory, pupillomotor, and sexual [women]) and total scores of the SCOPA-AUT questionnaire (p < 0.05). In the patient group, there was a significant correlation between the total scores and subscale scores (gastrointestinal, cardiovascular, and thermoregulatory subscales) of the SCOPA-AUT questionnaire and disease severity. Moreover, ESS was positively correlated with the total scores and subscale scores (urinary, cardiovascular, and pupillomotor) of the SCOPA-AUT questionnaire. Conclusion: Disease severity and daytime sleepiness may be related to autonomic dysfunction in RLS. Further studies focusing on autonomic functions in RLS are required to improve management strategies and clinical outcomes.