Leg movement activity during sleep in multiple sclerosis with and without RLS.

Abstract

STUDY OBJECTIVES\nTo carry out an analysis of leg movement activity during sleep in a polysomnography (PSG) dataset of patients with multiple sclerosis (MS), in comparison to idiopathic restless legs syndrome (iRLS) and healthy controls.\n\n\nMETHODS\nIn this cross-sectional, observational, instrumental study, fifty-seven patients (males/females: 11/46; mean age 46.2±10.2 years) with a diagnosis of MS underwent a telephone interview assessing the five standard diagnostic criteria for RLS and PSG. Sleep architecture and leg movement activity (LMA) during sleep were subsequently compared: 1) 40 MS patients without RLS (MS-RLS) vs. 28 healthy controls; 2) 17 MS patients with RLS (MS+RLS) vs. 35 patients with iRLS; 3) MS+RLS vs. MS-RLS.\n\n\nRESULTS\nMS-RLS and MS+RLS presented increased sleep latency, percentage of sleep stage N1, and reduced total sleep time compared to healthy controls and iRLS, respectively. The periodic limb movements during sleep (PLMS) index (PLMSI) was higher in MS-RLS than in healthy controls (p = 0.035) and lower in MS+RLS compared to iRLS (p = 0.024). PLMS in MS+RLS were less periodic, less often bilateral and with shorter single movements, compared to the typical PLMS in iRLS.\n\n\nCONCLUSIONS\nMS is a risk factor for RLS, PLMS, and for a lower sleep quality in comparison to healthy patients. PLMS in MS+RLS are fewer and shorter if compared to iRLS. Our results suggest a dissociation between motor (PLMS) and sensory symptoms (RLS sensory component) in RLS secondary to MS, with possible treatment implications.