Restless legs syndrome: associated non-motor symptoms and medical comorbidities: a controlled study

Abstract

Introduction: Restless legs syndrome (RLS) is a chronic sensorimotor disorder characterized by discomfort or pain, predominantly in the legs, resulting in an urge to move during times of rest. These disturbances are often accompanied by sleep fragmentation, which can significantly increase medical comorbidities over time and can have a detrimental effect on a patient’s overall quality of life. In this retrospective study, we examined the temporal relationship between the time of RLS diagnosis and the onset of non-motor symptoms (NMS) and medical comorbidities. Patients and methods: Thirty-six RLS patients were evaluated for age at: symptom onset, time of diagnosis, time of occurrence of NMS, and medical comorbidities. We used structured interviews, validated questionnaires, and past medical records to aggregate and verify patient data. There was no clinical evidence to suggest secondary RLS in any patient at time of diagnosis. Results: Twenty-five patients were diagnosed as having RLS alone and eleven were diagnosed with RLS and Parkinson’s disease (RLS + PD). In the RLS + PD group, irrespective of which disorder presented first, we found that patients exhibited symptoms of RLS at a significantly later age than those patients with RLS alone (P,0.05). The incidence and severity of NMS were significantly higher in the RLS + PD group compared to RLS alone and controls (P,0.001). Increased risk of RLS was identified in patients exhibiting mood changes and sleep deficits, and these risk factors manifested 5 and 10 years prior, respectively, to their diagnosis. Conclusion: Primary RLS develops earlier in those patients who only have RLS compared to those who later also develop PD. Mood and sleep impairment can be present years prior to the diagnosis of RLS. Other medical comorbidities associated with RLS included hypertension, hyperlipidemia, arthritis, chronic pain, and diabetes.