Restless legs syndrome - the under-recognised non-motor burden: a questionnaire-based cohort study

Objectives: Non-motor symptoms (NMS) range from neuropsychiatric to pain and are an important but underexplored feature of restless legs syndrome (RLS). There are currently no tools available which enable the holistic assessment of NMS in RLS in clinical practice. The primary aim of this study was to systematically assess NMS prevalence and burden in patients with RLS using the NMS Questionnaire (NMSQuest) validated for Parkinson's disease. Methods: Patients with idiopathic RLS according to the criteria of the international RLS study group (IRLSSG) were included. Patients underwent a physical examination and clinical interview as well as completed the NMS Questionnaire and the international restless legs syndrome study group (IRLSSG) rating scale. Results: Seventy-four patients with primary RLS were included (mean age 64.6 ± 14.4 years, 62.2% female, mean disease duration 23.5 ± 17.8 years, mean Levodopa equivalent daily dose 63.3 ± 67.4 mg). On average patients reported an IRLSSG rating scale score of 24.8 ± 8.2 (maximum 40) and NMSQuest score of 9.9 ± 5.0 (maximum 30). Patients reported a minimum of two NMS with the majority (39.2%) reporting a moderate NMS burden, followed by severe (28.4%) and very severe (17.6%) burden. The most frequent NMS were insomnia (89.2%) followed by nocturia (70.3%), feeling sad (59.5%), forgetfulness (54.1%), urgency (47.3%), feeling anxious (43.2%), unexplained pain (41.9%), difficulty concentrating (40.5%) and dizziness (40.5%). There were no significant differences in NMSQuest total scores according to disease duration and gender (p = 0.739, p = 0.849). Conclusion: In conclusion, this study is one of the first to address NMS in RLS systematically and the data underlines the need to holistically assess NMS in RLS in order to deliver true value-based healthcare for these patients.