Theta Activity at Sleep Onset in Children with Autism Spectrum Disorder.

Researchers used sleep studies to measure brain waves in children with autism compared to typical children. They found that 30% of autistic children had unusual theta brain waves when falling asleep, compared to only 6% of typical children. Children with autism who had these unusual brain waves at bedtime had more difficulty recognizing emotions and showed trends toward more challenging daytime behaviors. This research helps explain why sleep problems might make autism symptoms worse.

This polysomnography study examined theta activity at sleep onset (TASO) in 60 children and adolescents with autism spectrum disorder compared to 70 typically developing controls. TASO was significantly more prevalent in ASD participants (30%) versus controls (6%). Children with ASD who exhibited TASO performed significantly worse on affect recognition tests with a large effect size, suggesting impaired social cognition. While TASO wasn't associated with other cognitive measures, there was a trend toward worse daytime behavior.

These findings provide objective evidence of altered sleep architecture in ASD and suggest a potential mechanism linking sleep disturbances to social cognitive difficulties and symptom severity in autism.

Sleep assessments using polysomnography may help identify children with ASD at risk for social cognitive difficulties. TASO could serve as an objective biomarker for sleep-related impacts on daytime functioning. Findings support the clinical importance of addressing sleep disturbances in autism intervention planning and highlight potential mechanisms linking sleep and social cognition.

Single study with cross-sectional design. Sample size details not fully reported in abstract. Limited to visual analysis of polysomnography data. Trend-level associations suggest need for replication. Causal relationships cannot be established from this observational study design.

Despite the enormous clinical relevance of disordered sleep to autism spectrum disorder (ASD), to date, few studies have employed objective measures of sleep architecture in ASD. Previous studies have identified an association between slow wave activity in electroencephalography (EEG) at sleep onset and daytime cognitive and affective functioning in other neuropsychiatric disorders. However, it is unknown whether slow wave activity, particularly Theta activity, at sleep onset is present more in ASD and whether it is related to daytime functioning. We used polysomnography (PSG) to investigate the presence of Theta activity at sleep onset in 60 children and adolescents aged 5.6-18.3 years old with ASD and 70 typically developing controls (TD).

We performed visual analysis of PSG to identify bursts of theta activity at sleep onset (TASO) and examined its association with cognition, affect, and daytime behavior in children with ASD. TASO was more prevalent in ASD participants (30%) compared to controls (6%). The TASO (+) group scored significantly worse on the affect recognition test with a large effect size (18.6 (8.0) vs. 23.5 (5.5), t = 2.30, p = 0.027, d = 0.75). TASO was not associated with any other cognitive or affective measures; however, there was a trend toward association with worse daytime behavior.

Our findings identify TASO as a feature of objective sleep in children with ASD, and provide a potential mechanism underlying previous reports of an association between poor sleep and ASD symptom severity, especially social cognition.