Characterizing Sleep Spindles in Children with Autism Spectum Disorder (ASD), Developmental Delay and Neurotypical Development. (P3.209)

Objective: To determine if sleep spindle number, frequency and duration during N2 sleep differs in children with ASD from children with DD without autism and TYP children. Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interactions and behavioral abnormalities. While there is increasing evidence of altered brain connectivity in autism, the degree and direction of these alterations in connectivity and their uniqueness to autism has not been established. Sleep spindles in stage 2 (N2) of NREM sleep have been demonstrated to be a robust measure of connectivity between the thalamus and cortex and play a critical role in neuronal plasticity and memory consolidation. Design/Methods: - Sleep spindle data were obtained from 135 children aged 2 to 6 years with ASD (n = 85, 84% ♂), DD without autism (n = 21, 62% ♂) and TYP (n = 29, 72% ♂). - Overnight digital EEGs with video recordings were recorded during the awake, drowsy, and sleep states. Spindles were counted for 5 minutes in 4 consecutive N2 epochs (total = 20 min). Average spindle frequency and duration within these N2 epochs were also computed. Results: - Number of spindles increased with age in all three groups (p -Spindle duration increased with age (p Conclusions: - Children with ASD had lower spindle number and shorter spindle duration than TYP children. When compared to children with DD without autism, children with ASD had fewer spindles. -This study indicates that spindles are a robust biological marker that distinguishes children with ASD from developmental delay and neurotypicals; provides evidence for altered connectivity between thalamo-cortical regions in children with ASD. Study Supported by: This work was supported by the Intramural Program of the National Institute of Mental Health of the National Institutes of Health (ZIAMH002914, Protocol NCT00298246). The views expressed in this paper do not necessarily represent the views of the NIMH, NIH, HHS, or the United States Government. Protocol number 06-M-010. Disclosure: Dr. Chilakamarri, MD has nothing to disclose. Dr. Thurm, PhD has nothing to disclose. Dr. Farmer, PhD has nothing to disclose. Dr. Swedo has nothing to disclose. Dr. Burroughs has nothing to disclose. Dr. Holmes has received personal compensation for activities with Sunovion, Eisai, Questqor, and Lundbeck for advisory board activities. Dr. Buckley, MD has nothing to disclose.