Topographical caracterisation of the painful restless legs syndrome

Abstract

The restless legs syndrome (RLS) is characterized by a core sensory component that is an urge to move the limbs. This sensation is frequently associated with pain of the same limbs. No previous studies have compared topographically painful to non-painful RLS subgroups. The aim of this study was to evaluate the clinical and especially topographical features of the painful RLS subtype. Forty-four patients with primary RLS all treated but without augmentations, were interviewed face to face with a semi-structured questionnaire. The patients responded to the presence or absence of painful RLS sensations. They also answered questions about demographics, clinical RLS features, RLS treatment, RLS impact (sleep disturbances, depression, and fatigue scales), and RLS sensations’ topography (anatomical localization, lateralization and spatial spreading when symptomatic). The patients reported subsequently the localization of their RLS sensations by drawing on a human body diagram. The paper drawings were scanned and specific surface areas of the body diagram were measured (complete body diagram, both upper limbs, and both lower limbs surface areas; and the respective surface areas affected by RLS sensations). We then calculated for each patient the percentage of surface area affected by RLS sensations for all the above mentioned variables. Finally, we superposed together the body diagrams of the patients in the painful RLS subgroup and did the same for those in the non-painful RLS subgroup. Twenty-seven (61%) patients considered their RLS sensations to be painful. There were no statistical differences for all the demographical, clinical and topographical variables tested between the painful (27 patients) and the non-painful (17 patients) RLS subgroups (based on the Bonferroni correction for multiple testing). However, the patients with painful RLS had a tendency toward a higher daytime sleepiness (10.1 ± 3.9 versus 6.8 ± 5.7; p = 0.0174) and a more frequent treatment with opioids (41% versus 12%; p = 0.0402) compared to the patient with non-painful RLS. Moreover, the patients in the painful RLS subgroup tended to have a more frequent involvement of the upper limbs (74% versus 29%; p = 0.0036) with mainly the forearms (48% versus 18%; p = 0.0406). Painful RLS could be a more severe and frequently upper limb affecting subtype of RLS. The authors are grateful to the French Association of Patients with RLS (Association France Ekbom, AFE) for funding this study.