Prevalence and profile of Restless Legs Syndrome in Parkinson's disease and other neurodegenerative disorders: A case-control study

Background: Restless Legs Syndrome (RLS) is associated with impaired central dopaminergic neuro-transmission. Though a link between RLS and parkinsonism has been proposed, the prevalence of RLS in parkinsonian disorders is poorly documented. Objective: To determine the prevalence of RLS in patients with Parkinson's Disease (PD), Progressive Supranuclear Palsy (PSP), Multiple System Atrophy (MSA) and Dementia with Lewy Bodies (DLB). Methods: We evaluated 187 consecutive patients with parkinsonian disorders (PD = 134, PSP = 27, MSA = 21, DLB = 5) and 172 healthy controls. RLS was diagnosed using the International RLS Study Group (IRLSSG) criteria and the severity of RLS was assessed in patients with definite RLS. Quality of sleep was evaluated with established scales. Results: The prevalence of RLS was higher in patients compared to controls (9.6% vs. 2.9%; p = 0.009) and was highest in PD (11.9%). RLS was present in only one patient each with MSA and PSP and none with DLB. The mean IRLSSG severity score of patients was 16.2 +/- 6.5. The global Pittsburgh Sleep Quality Index score and Epworth Sleepiness Scale score were significantly higher in patients compared to controls (p < 0.001). PD patients with RLS had lower Parkinson's Disease Sleep Scale (PDSS) score compared to patients without RLS (p = 0.023). There was no significant difference in gender, age, duration and severity of PD between the two groups. Conclusions: Our study found a higher prevalence of RLS in PD compared to healthy controls or other parkinsonian disorders. Apart from PDSS score, there was no significant difference in the clinical characteristics of PD patients with and without RLS. (C) 2013 Elsevier Ltd. All rights reserved.