Suzuki K, et al. – This multicenter case–controlled study aimed to examine the prevalence and effect of restless legs syndrome (RLS) and leg motor restlessness (LMR) in patients with Parkinson's disease (PD). In PD patients, the researchers demonstrated an increased prevalence of LMR but not RLS. LMR could be an early manifestation of PD. However, whether LMR was within the range of RLS or whether LMR and RLS constitute different entities in PD needed further studies.

• The researchers included 436 PD patients and 401 age– and sex–matched controls in this study.
• They diagnosed RLS based on 4 essential features.
• They diagnosed LMR when a participant showed the urge to move his or her legs but did not meet the four essential features of RLS.

• While LMR prevalence was significantly higher in PD patients than in controls (12.8% vs. 4.5%), the RLS prevalence did not differ between PD patients and controls (3.4% vs. 2.7%).
• Compared to controls with RLS or LMR, PD patients with RLS or LMR had a higher prevalence of excessive daytime sleepiness (EDS) (50.7%, vs. 6.9%), probable REM sleep behavior disorder (38.0% vs. 3.4%) and PD–related sleep problems (49.3% vs. 20.7%).
• RLS/LMR preceding PD onset was associated with an older age of PD onset.