Associations between sleep problems, cortical morphometry, and structural brain network organization in preschool children with autism: a retrospective observational study.

UNLABELLED: Sleep problems are highly prevalent in autism spectrum disorder (ASD) and may contribute to behavioral challenges and atypical brain development. However, the neuroanatomical mechanisms linking sleep problems and ASD during early childhood remain underexplored. This retrospective observational study included 183 preschool children with ASD, grouped by sleep problem status using the Children's Sleep Habits Questionnaire (CSHQ). Structural MRI data were processed with FreeSurfer to obtain cortical volume measures across 68 regions. Structural covariance networks were constructed to assess topological properties using graph theory. Group comparisons and exploratory correlation analyses were conducted to evaluate associations with behavioral measures. No significant group differences were found in total cortical or subcortical volumes. Exploratory analyses revealed uncorrected focal differences in the peri-calcarine cortex and right pars orbitalis, but these did not survive correction for multiple comparisons. Network analyses showed significantly reduced local connectivity (clustering coefficient, local efficiency) and altered small-world topology (Gamma, Sigma) in children with sleep problems, with preserved global efficiency. Exploratory correlations suggested that regional volumes may be linked to repetitive behaviors and withdrawn symptoms, although these did not remain significant after correction.

CONCLUSION: Preschool children with ASD and sleep problems show disrupted local brain network properties, particularly in sensory and social-cognitive regions. While some regional associations with behavior were observed, they should be interpreted cautiously due to their exploratory nature. These findings support the importance of considering sleep in neurodevelopmental assessments and highlight the need for longitudinal studies with objective sleep measures.

WHAT IS KNOWN: • Sleep problems are highly prevalent in children with autism spectrum disorder (ASD) and are linked to adverse behavioral outcomes. • Structural covariance networks (SCNs) reflect coordinated brain development and are altered in ASD.

WHAT IS NEW: • This study explores associations between sleep problems and both cortical morphology and SCNs in preschoolers with ASD. • Exploratory analyses reveal regional volume trends and altered network topology in children with sleep problems, suggesting potential early neural correlates.