586 Large Body Movements on Video-Polysomnography are Associated with Daytime Dysfunction in Children with Restless Sleep Disorder

Introduction Restless sleep disorder (RSD) is a recently described disorder of children and adolescents with complaints of restless sleep and is characterized by large body movements which interfere with nocturnal sleep, are associated with daytime dysfunction, and are not better explained by another disorder (1, 2). Polysomnography criteria for RSD includes the scoring of large body movements (LBMI) and identified an LBMI ≥ 5 as sensitive and specific for RSD. As data is currently limited to two pediatric centers, our study aims to identify RSD cases at our institution, characterize their PSG, and determine their effect on daytime dysfunction and quality of life. Methods This single center retrospective study included 41 children with complaints of restless sleep and 35 sex- and age-matched children with RLS/PLMD collected from February 2018 to November 2020. The video PSGs were re-scored utilizing the previously published criteria (1,3). We used two LBMI thresholds, LBMI ≥ 5 and an exploratory LBMI ≥ 4. We then compared Epworth Sleepiness Scores (ESS), Pediatric Quality of Life measures (PedsQL), PSG characteristics, LBM associated awakenings and ferritin level between groups. Results Twenty-one children (mean age=8.3 ± 3.13 SD) met the LBMI>=4 criteria, of which 11 (age=8.4±3.81 SD) met the LBMI>=5 criteria. All three groups reported decreased quality of life (PedsQL total LBMI>=4=66.21±20.28, LBMI>=5=72.39±18.24, RLS/PLMD=55.54±19.86), low mean ferritin values (LBMI>=4=33.18 ± 20.11, LBMI>=5 =28.38 ± 12.68, RLS/PLMD = 36.57±25.46), and increased wake after sleep onset (WASO) (LBMI>=4 = 42.82 ± 34.26, LBMI>=5=44.38 ± 38.4, RLS/PLMD = 52.34 ± 42.03), with no significant differences between groups. Both LBMI>=4 and LBMI>=5 groups exhibited higher ESS compared to the RLS/PLMD group (LBMI>=4=10.36±7.13; LBMI>=5=11.13±5.19; RLS/PLMD=6.17±4.04; LBMI>=4 vs RLS/PLMD, P=0.05; LBMI>=5 vs RLS/PLMD, P = 0.032). Both awakenings and WASO associated with LBM were high in LBMI>=4 and LBMI>=5 (Awakenings: LBMI>=4=8.43±9.96, LBMI>=5 =8.00±12.19, WASOassociatedLBM: LBMI>=4=23.60±44.64 LBMI>=5=29.46±57.57) Conclusion One quarter of children with complaints of restless sleep met the standard criteria for RSD. Both children with RSD (including the exploratory LBMI≥ 4 group) and RLS/PLMD had increased WASO, low ferritin and decreased quality of life, but the RSD group had more daytime sleepiness compared to RLS/PLMD. Support (if any):