Effects of Transcranial Direct Current Stimulation on Excitatory/Inhibitory Balance and Behavior in Children With Autism-A Randomized Controlled Study.

Background: Autism spectrum disorder (ASD) is a multifaceted neurodevelopmental disorder marked by impaired interactions and restricted interests, the pathophysiology of which is not fully understood. The current study explored the potential therapeutic effects of transcranial direct current stimulation (tDCS) on the neurophysiological aspects of ASD, specifically focusing on the brain's excitatory/inhibitory (E/I) balance and behavioral outcomes, providing scientific guidance for ASD intervention.

Methods: Forty-two children with ASD were randomly divided into either an active tDCS or sham tDCS group. Electroencephalography (EEG) recordings were conducted before and after stimulation to assess E/I changesusing EEG markers including α oscillations and the aperiodic exponent, and average spatial phase synchronization (ASPS) analysis and detrended fluctuation analysis (DFA) were performed. Behavioral changes were evaluated using the Autism Behavior Checklist (ABC) and the Social Responsiveness Scale (SRS).

Results: Active tDCS resulted in significant increases in α oscillation power, reductions in α bandwidth, and improvements in γ-band ASPS and DFA values. Furthermore, participants in the active tDCS group exhibited improvements in behavioral scores on the ABC and SRS, with enhancements in social communication, sensory processing, and adaptive behavior. We found no significant changes in the sham group.

Conclusion: These findings suggest that tDCS intervention effectively reduced brain excitability and improved E/I balance and behavioral outcomes in children with ASD. The results warrant further investigation into the efficacy and underlying mechanisms of tDCS for ASD treatment.

Clinical trial registration: No: ChiCTR2400092790, https://www.chictr.org.cn/showproj.html?proj=249950.