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Updated: Jul 2, 2025
Infant Auditory Processing and Event-related Brain Oscillations
Published on: July 1, 2015
Differences in Sleep EEG Coherence and Spindle Metrics in Toddlers With and Without Language Delay: A Prospective
Xinyi Hong1, Cristan Farmer2, Nataliia Kozhemiako3
1National Institute of Mental Health Division of Intramural Research Programs: National Institute of Mental Health Intramural Research Program.
Insights
Toddlers with language delays show altered sleep brainwave patterns and sleep spindle development. These neurophysiological differences in early childhood may help identify atypical neurodevelopmental trajectories.
Area of Science:
- Neuroscience
- Developmental Psychology
- Sleep Medicine
Background:
- Sleep is vital for early language acquisition.
- Sleep disturbances are prevalent in children with neurodevelopmental disorders.
- Analyzing sleep microarchitecture in toddlers can reveal neurophysiological markers for early detection of developmental delays.
Conclusions:
- Atypical sleep EEG connectivity and sleep spindle development are detectable in toddlers aged 12-36 months.
- These findings provide insights into the neurophysiological underpinnings of neurodevelopmental disorders.
- Early identification of sleep abnormalities may aid in understanding and intervening in atypical neurodevelopmental trajectories.
Background:
Sleep plays a crucial role in early language development, and sleep disturbances are common in children with neurodevelopmental disorders. Examining sleep microarchitecture in toddlers with and without language delays can offer key insights into neurophysiological abnormalities associated with atypical neurodevelopmental trajectories and potentially aid in early detection and intervention.
Methods:
Here, we investigated electroencephalogram (EEG) coherence and sleep spindles in 16 toddlers with language delay (LD) compared with a group of 39 typically developing (TD) toddlers. The sample was majority male (n = 34, 62%). Participants were aged 12-to-22 months at baseline, and 34 (LD, n=11; TD, n=23) participants were evaluated again at 36 months of age.
Results:
LD toddlers demonstrated increased EEG coherence compared to TD toddlers, with differences most prominent during slow-wave sleep. Within the LD group, lower expressive language skills were associated with higher coherence in REM sleep. Within the TD group, lower expressive language skills were associated with higher coherence in slow-wave sleep. Sleep spindle density, duration, and frequency changed between baseline and follow-up for both groups, with the LD group demonstrating a smaller magnitude of change than the TD group. The direction of change was frequency-dependent for both groups.
Conclusions:
These findings indicate that atypical sleep EEG connectivity and sleep spindle development can be detected in toddlers between 12 and 36 months and offers insights into neurophysiological mechanisms underlying the etiology of neurodevelopmental disorders.
Trial Registration:
https://clinicaltrials.gov/study/NCT01339767; Registration date: 4/20/2011.
