Sleep. 2025 Jul 13:zsaf194. doi: 10.1093/sleep/zsaf194. Online ahead of print.
ABSTRACT
STUDY OBJECTIVES: Large muscle group movements during sleep (LMMS) have recently been recognized as a prevalent feature in patients with Restless Legs Syndrome (RLS), yet their autonomic profile remains insufficiently characterized. This study aimed to compare heart rate (HR) changes associated with LMMS to those accompanying short-interval (SILMS), periodic (PLMS), and isolated leg movements (ISOLMS) during non-REM sleep in RLS.
METHODS: Thirty drug-free RLS patients (20 women, mean age 57.6 ± 12.73 years) underwent full-night polysomnography. For each subject, five arousal-associated events per movement type were selected, provided they were isolated by at least 30 seconds of motor/arousal-free sleep. HR changes were analyzed by computing R-R intervals and expressing them as a percentage of baseline, synchronized to movement onset. The area under the curve (AUC, -10 to +20 s), HR change peak, and movement durations were statistically compared using non-parametric tests.
RESULTS: LMMS were significantly longer than other movement types (mean duration: 9.3 s vs. <3.0 s for others) and induced the highest HR response (peak: 129.6%, AUC: 369.3%), followed by SILMS (peak: 125.4%, 266.3%), ISOLMS (peak: 118.2%, 173.4%), and PLMS (peak: 118.5%, 166.9%). SILMS and LMMS were associated with rapid and sustained HR increases, without post-peak bradycardia, while PLMS and ISOLMS showed a modest transient bradycardia following the peak.
CONCLUSIONS: LMMS are associated with strong autonomic activation indicating parasympathetic withdrawal and/or sympathetic activation, distinguishing them from other sleep-related leg movements in RLS. The absence of post-peak bradycardia suggests reduced parasympathetic buffering, potentially reflecting more sustained arousal mechanisms.
PMID:40652310 | DOI:10.1093/sleep/zsaf194
