Static and dynamic low- and high-order brain functional network modulations by tDCS in children with autism spectrum disorder.

Researchers studied a brain stimulation technique called tDCS in 42 young children with autism (ages 4-6). They measured brain activity before and after treatment using EEG brain scans. The treatment appeared to improve how different brain regions communicate with each other, making brain networks more efficient. Children who received real stimulation showed some behavioral improvements compared to those who received fake stimulation, but more research is needed to understand these changes better.

This randomized controlled trial investigated transcranial direct current stimulation (tDCS) effects on brain network organization in 42 children with autism aged 4-6 years. Using EEG analysis, researchers examined both static and dynamic functional connectivity patterns before and after intervention. Active tDCS increased low-order functional connectivity in delta, alpha, and beta frequency bands, with more widespread increases in high-order connectivity across all frequencies. Network topology changes included reduced characteristic path length and increased global and local efficiency, particularly in delta and theta bands.

Dynamic network analysis showed tDCS modulated state entropy at specific time scales. While behavioral improvements trended toward significance in the active group, these were not the primary focus and require future clarification.

tDCS shows promise as a neuromodulation intervention for young children with autism by enhancing brain network connectivity and efficiency. However, clinical significance remains unclear. Larger studies with longer follow-up periods and standardized behavioral assessments are needed before clinical implementation can be recommended.

Small sample size of 42 participants limits generalizability. Behavioral improvements were not statistically significant and not the primary focus. Relationship between neural changes and clinical outcomes unclear. Single-site study with short-term follow-up only.

Autism spectrum disorder (ASD) is characterized by aberrant functional brain connectivity and deficits in network dynamics. Transcranial direct current stimulation (tDCS) has emerged as a promising intervention with potential therapeutic effects; however, its effects on both static and dynamic functional brain network organization remained insufficiently understood. A total of 42 children with ASD aged 4-6 years were enrolled and randomly assigned to either active tDCS or sham stimulation groups. Resting-state electroencephalography (EEG) data were acquired before and after the intervention.

Low-order functional connectivity (LOFC) and high-order functional connectivity (HOFC) networks were constructed, followed by graph-theoretical analyses to assess clustering coefficient, characteristic path length, global efficiency, and local efficiency. Furthermore, state entropy was employed to evaluate dynamic network transitions between integrated and segregated states. Active tDCS was associated with increased LOFC strength in the delta, alpha, and beta bands, and more widespread increases in HOFC across all examined frequency bands. Changes in network topology were primarily observed in HOFC, with reductions in characteristic path length and increases in global and local efficiency, particularly in the delta and theta bands.

Dynamic network analysis indicated that tDCS modulated state entropy at specific time scales in both LOFC and HOFC networks. These findings suggest shifts in functional coordination and temporal variability among the recorded regions. Behavioral measures exhibited a trend toward improvement in the active group; however, these changes were not the focus of the present analysis, and their relationship to neural modulation remains to be clarified in future work. tDCS modulated functional interaction patterns and dynamic state characteristics among the recorded brain regions in children with ASD. These results provide preliminary neurophysiological evidence regarding the influence of tDCS on both static and dynamic network organization and highlight potential network-based markers to guide future individualized neuromodulation research.

Further studies with larger samples and longitudinal follow-ups are needed to clarify the functional and clinical significance of these network-level changes.