Kang Jiannan, Wu Juanmei, Huang Xinping, Mao Wenqin, Li Xiaoli
Child Rehabilitation Division, Ningbo Rehabilitation Hospital, Ningbo, China.
State Key Laboratory of Cognitive Neuroscience and Learning, Beijing, China.
IBRO Neurosci Rep. 2025 Jan 6;18:171-179. doi: 10.1016/j.ibneur.2025.01.005. eCollection 2025 Jun.
Autism spectrum disorder (ASD) is a complex and heterogeneous neurodevelopmental disorder with few effective treatment options. In recent years, transcranial direct current stimulation (tDCS) has been applied in interventions for ASD, often targeting the left dorsolateral prefrontal cortex (DLPFC). However, studies investigating anodal and cathodal tDCS interventions have reported differing outcomes. Therefore, this study aimed to compare and analyze the effects of these two stimulations through a randomized controlled trial, utilizing both behavioral assessments and EEG proxy markers capable of characterizing the brain's excitatory-inhibitory balance.
This study recruited a total of 24 children with ASD (20 males and 4 females; mean age ± SD: 5.5 ± 1.2 years), who were randomly divided into two groups receiving either anodal or cathodal tDCS targeting the DLPFC. The stimulation intensity was set at 1 mA, administered five times per week for a total of 20 sessions. Behavioral intervention outcomes were assessed using the Social Responsiveness Scale (SRS) and the Autism Behavior Checklist (ABC). Additionally, the study evaluated the effects of tDCS on the brain's excitatory-inhibitory balance by analyzing corrected periodic alpha oscillation power and bandwidth, as well as non-periodic exponent and offset derived from EEG data.
Following anodal tDCS intervention, results from the SRS scale indicated a decrease in overall scores, with significant differences observed in social communication and social motivation among children. On the ABC scale, overall scores also decreased, with significant differences noted in sensory behavior, social relating, body and object use, and language and communication skills. Non-periodic exponent and offsets increased following anodal tDCS stimulation, whereas they decreased after cathodal tDCS stimulation. Regarding alpha oscillation power, there was a significant increase following anodal tDCS and a significant decrease following cathodal tDCS. In terms of alpha oscillation bandwidth, there was a reduction following anodal tDCS and an increase following cathodal tDCS. Further correlation analysis revealed that in children who received anodal tDCS intervention, non-periodic exponent showed correlations with behaviors such as social communication.
Our study results demonstrated that anodal and cathodal tDCS targeting the left DLPFC had distinct effects on the behavior and excitatory-inhibitory balance of children with ASD. Anodal tDCS intervention appeared to have a more positive impact compared to cathodal intervention. However, the sample size was small, and we focused solely on the effects of tDCS, with our experimental design perhaps not being able to generalize to all external manipulations of excitability in our study. In future research, we will continue to improve the experiments to address these limitations.
自闭症谱系障碍（ASD）是一种复杂的异质性神经发育障碍，有效的治疗方案很少。近年来，经颅直流电刺激（tDCS）已应用于ASD的干预，通常针对左侧背外侧前额叶皮层（DLPFC）。然而，研究阳极和阴极tDCS干预的结果却有所不同。因此，本研究旨在通过随机对照试验，利用行为评估和能够表征大脑兴奋抑制平衡的脑电图代理指标，比较和分析这两种刺激的效果。
本研究共招募了24名ASD儿童（20名男性和4名女性；平均年龄±标准差：5.5±1.2岁），他们被随机分为两组，分别接受针对DLPFC的阳极或阴极tDCS。刺激强度设定为1 mA，每周进行5次，共20次。使用社会反应量表（SRS）和自闭症行为检查表（ABC）评估行为干预结果。此外，该研究通过分析校正后的周期性阿尔法振荡功率和带宽，以及从脑电图数据得出的非周期性指数和偏移，评估tDCS对大脑兴奋抑制平衡的影响。
阳极tDCS干预后，SRS量表结果显示总分下降，儿童在社会沟通和社会动机方面存在显著差异。在ABC量表上，总分也下降，在感觉行为、社会关系、身体和物体使用以及语言和沟通技能方面存在显著差异。阳极tDCS刺激后非周期性指数和偏移增加，而阴极tDCS刺激后则下降。关于阿尔法振荡功率，阳极tDCS后显著增加，阴极tDCS后显著下降。在阿尔法振荡带宽方面，阳极tDCS后降低，阴极tDCS后增加。进一步的相关分析表明，在接受阳极tDCS干预的儿童中，非周期性指数与社会沟通等行为存在相关性。
我们的研究结果表明，针对左侧DLPFC的阳极和阴极tDCS对ASD儿童的行为和兴奋抑制平衡有不同的影响。与阴极干预相比，阳极tDCS干预似乎有更积极的影响。然而，样本量较小，且我们仅关注tDCS的效果，我们的实验设计可能无法推广到我们研究中所有兴奋性的外部操作。在未来的研究中，我们将继续改进实验以解决这些局限性。
