Video-polysomnographic characterization of sleep movements in children with restless sleep disorder

Study objectives: Children with "restless sleep disorder" (RSD) were previously identified clinically and polysomnographically. In this study, we attempt to characterize their sleep-related movements and describe them in terms of type of movement, duration, and timing.

Methods: Video-polysomnography (vPSG) from 15 school-aged children with RSD, 15 sex- and age-matched children with restless legs syndrome (RLS), and 15 controls was reviewed for identification of sleep-related movements. Data obtained included the routine data collected during PSG and the video assessment of the movements which included time of the night when the movement occurred, type of movement (arms, legs, and body position change), and duration of the movement.

Results: vPSG recordings from 15 children with RLS (12 males, 3 females) with a mean age of 11.9 (SD: 3.52), 15 participants with RSD (11 males, 4 females) with a mean age of 9.5 (SD: 3.18), and 15 controls (9 males, 6 females) with a mean age of 10. The total movement index, obtained by summing together all types of movements in each participant and dividing it by the total sleep time, was prominent in children with RSD in all sleep stages. Five movements per hour gave 100% accuracy vs. controls and 90% vs. RLS. Movements occurred all night.

Conclusions: We have characterized the sleep-related movements of children with RSD in comparison to the movements in children with RLS and in controls. We identified that children with RSD move all night and an index of 5 per hour accurately separates RSD from other disorders.