New research presented at SLEEP 2025 found that pediatric patients with autism spectrum disorder may exhibit increased brain excitability in the auditory cortex, which could be associated with poorer sleep quality.
The findings offered insight into possible neural mechanisms underlying sleep disturbances common in autism.
Sleep difficulties affect up to 80% of pediatric patients with autism, including delayed sleep onset, frequent night wakings, and reduced total sleep time. Previous studies have linked these issues to sensory sensitivities, particularly to sound, but the brain-based connection remained unclear.
In the study, researchers included 42 pediatric patients aged 6 to 11 years: 25 typically developing and 17 with autism spectrum disorder (ASD). All participants wore an actigraphy device for 2 weeks to track sleep patterns and subsequently underwent a 12-minute functional magnetic resonance imaging (fMRI) scan.
The researchers measured brain activity in the left and right primary auditory cortex, which processes sound. They used the Hurst Exponent, a statistical measure derived from fMRI, to estimate the brain’s excitation/inhibition balance. Lower Hurst values suggested greater excitability and potential sensory hypersensitivity.
The patients with autism had lower Hurst Exponent values in both auditory cortices, indicating increased excitability. They also had longer sleep onset, shorter total sleep time, and lower sleep efficiency compared with their typically developing peers.
Across all participants, regardless of diagnosis, lower Hurst Exponent values in the right auditory cortex were associated with lower sleep efficiency. There was also a near-significant link between lower values and increased wakefulness after sleep onset. A similar, though not statistically significant, pattern was observed in the left auditory cortex.
The analysis controlled for age, in-scanner motion, and other potential confounders. No statistically significant differences were found in fMRI quality or actigraphy adherence between the groups.
Although preliminary, the results suggested that increased excitability in the auditory cortex may contribute to sleep problems. This pattern was observed across all patients, but those with ASD, who are more prone to sound sensitivity, may be more affected.
The study is ongoing and was funded by the U.S. Department of Defense and the National Institutes of Health.
Disclosures were not made available at time of publishing.
Source: Sleep
