Atypical Body Movements during Sleep in Young Children with Autism Spectrum Disorder

Background: Children with autism spectrum disorder (ASD) reportedly suffer from sleep problems at a higher rate than typically developing (TD) children. Several previous studies have reported differences in sleep indices (e.g., sleep latency) in children with ASD. However, no previous studies have focused specifically on the time course of body movements.

Objectives: We investigate the time course of body movements in young TD children and young children with ASD as well as the relationship between body movements during sleep and social ability.

Methods: Seventeen TD children and 17 children with ASD participated in this study (5 to 8 years old). We used an accelerometer attached to the waist to record movements during sleep and measured the average time course of body movements for 3 nights.

Results: Our results demonstrated that the rate of body movement 2 to 3 hours after sleep onset was higher in children with ASD than in TD children. In addition, the higher rate of body movement at 0.5 to 1 hour after sleep onset was associated with a lower social ability in the children with ASD.

Conclusions: Our results suggested that the time course of body movements is an objective behavioural index for young children with ASD.