Transcranial direct current stimulation and cognitive stimulation therapy in children with autism spectrum disorder: randomized, sham-controlled, double-blind, crossover, clinical trial

Abstract

BACKGROUND: Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technic that has been researched as a therapeutic alternative to reduce symptoms and improve cognitive functioning in many disorders, including autism spectrum disorder (ASD), a neurodevelopmental disorder in which functional changes are observed in some brain structures, damaging different areas of the individual’s lives. OBJECTIVE: To compare the effects of active and sham transcranial direct current stimulation during cognitive stimulation tasks training in children with an autism spectrum disorder. METHODS: A randomized, sham-controlled, double-blind, crossover clinical trial was conducted. Twelve children with ASD underwent ten cognitive training sessions combined with active and sham tDCS. Anodal tDCS was administered over the left dorsolateral prefrontal cortex (DLPFC). Executive functions and social cognition were evaluated before, after, and three months after (follow-up) the intervention. RESULTS: No differences were found in the effects between the two interventions. Considering the mean results before and after active tDCS, improvements were seen in the theory of mind function (pre-intervention: 14.58 ± 5.04; post-intervention: 17.08 ± 5.21 [d2 = 0.51)]; follow-up: 16.92 ± 5.52 [d2 = 0.46]) and inhibitory control (pre-intervention: -1.31 ± 1.90; follow-up: 0.25 ± 1.14, d2 = 1.04). CONCLUSION: The administration of active tDCS over the left DLPFC during the training of cognitive stimulation tasks did not result in superior effects compared to sham tDCS combined with training in children with an autism spectrum disorder.