High-frequency oscillations in autism spectrum disorder: are they related to clinical severity?

High-frequency oscillations are oscillatory high-frequency (>80 Hz) signals that can be physiological or pathological. Physiological high-frequency oscillations related to sleep spindles have been reported. In addition, some reports indicate that high-frequency oscillations are a marker for the prediction of seizures. Our aim was to explore the presence of high-frequency oscillations in children with autism spectrum disorder and their relationship with clinical symptoms. Fifty-two children with autism spectrum disorder and 49 healthy children were enrolled in the study. EEG records were evaluated via the open-source Python library magnetoencephalography and electroencephalography (MNE)-high-frequency oscillation for the detection of scalp high-frequency oscillations and sleep spindles detected by open-source YASA. SPSS version 22 used for statistical analysis. The duration of sleep spindle was shorter, and the frequency was significantly greater, in children with autism spectrum disorder than in healthy controls. High-frequency oscillations unrelated to sleep spindle were more common in children with autism spectrum disorder (P < 0.01). Younger children with autism spectrum disorder had particularly more high-frequency oscillations unrelated to sleep spindle (P < 0.01). Within the autism spectrum disorder group of patients, high-frequency oscillations unrelated to sleep spindle were significantly greater in subgroups with moderate-severe social interaction problems (P < 0.01), moderate-severe restricted interest (P = 0.018), and severe linguistic delays (P = 0.006). High-frequency oscillations might be a candidate marker for autism spectrum disorder that might be used in clinical settings that warrants further studies.