Large Muscle Group Movements during Sleep in Restless Leg Syndrome: Neurophysiological and Clinical Implications

Maria P Mogavero; Patrizia Congiu; Giuseppe Lanza; Sara Marelli; Alessandra Castelnuovo; Monica Puligheddu; Lourdes M DelRosso; Luigi Ferini Strambi; Raffaele Ferri

doi:10.1093/sleep/zsae113

Large Muscle Group Movements during Sleep in Restless Leg Syndrome: Neurophysiological and Clinical Implications

Sleep. 2024 May 18:zsae113. doi: 10.1093/sleep/zsae113. Online ahead of print.

Authors

Maria P Mogavero^{1

2}, Patrizia Congiu³, Giuseppe Lanza^{4

5}, Sara Marelli^{1

2}, Alessandra Castelnuovo^{1

2}, Monica Puligheddu³, Lourdes M DelRosso⁶, Luigi Ferini Strambi^{1

2}, Raffaele Ferri⁴

Affiliations

¹ Vita-Salute San Raffaele University, Milan, Italy.
² Sleep Disorders Center, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.
³ Sleep Disorder Research Center, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy.
⁴ Clinical Neurophysiology Research Unit and Sleep Research Centre, Oasi Research Institute-IRCCS, Troina, Italy.
⁵ Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy.
⁶ University of California San Francisco, Fresno, CA, USA.

PMID: 38761118
DOI: 10.1093/sleep/zsae113

Abstract

Study objectives: Recently, criteria have been drawn up for Large Muscle group Movements during sleep (LMM), defined as movements lasting for 3-45 seconds in adults, which are often accompanied by changes in sleep stage, arousals, and increases in heart rate. The aim of this study was to characterize LMM in RLS, in order to better evaluate their impact on the neurophysiology of the disorder and, therefore, the possible clinical implications.

Methods: Consecutive, drug-free patients diagnosed with RLS and controls, aged 18 years or more, were retrospectively enrolled. Leg movement activity - short-interval (SILMS), periodic (PLMS) and isolated (ISOLMS) leg movements during sleep - and LMM were detected and scored.

Results: One-hundred patients and 67 controls were recruited. All movement measures were significantly higher in RLS. A significant positive correlation was found between LMM and ISOLMS index but not PLMS index in both groups. LMM index showed a significant negative correlation with total sleep time, sleep efficiency, and percentage of sleep stages N3 and R, as well as a significant positive correlation with number of awakenings, and percentage of sleep stages N1 and N2 only in patients with RLS. No significant correlation was found for either LMM or PLMS index and RLS severity.

Conclusions: Different types of movements, including SILMS, ISOLMS, and LMM, play somewhat distinct roles in sleep neurophysiology in RLS. Notably, LMM, a newly recognized category of movements, demonstrate associations with sleep architecture instability and fragmentation, arousals, and awakenings, suggesting potential clinical implications.

Keywords: arousals; isolated leg movements during sleep; large muscle group movements during sleep; periodic leg movements during sleep; restless legs syndrome; sleep-related movements.