The Effects of Transcranial Direct Current Stimulation and Selective Motor Training on Fine Motor Skills in Children with Autism Spectrum Disorders

Introduction: Transcranial direct current stimulation (tDCS) is a noninvasive technique that modulates motor performance and learning. Previous studies have shown that tDCS over the primary motor cortex (M1) can facilitate consolidation of various motor skills in healthy subjects; but the effect of tDCS on motor skills improvement in autism spectrum disorders (ASD) remains unknown. The aim of the current study was to examine the effects of anodal tDCS and selective motor training on fine motor skills in 6-14-year-old children with ASD. Materials and Methods: This was an experimental research with a pretest–posttest design. A total of eighteen children with ASD (age range 6-14 years) were selected according to available sampling and inclusion criteria and then were randomly divided to experimental and control group. Nine subjects received 1.5 mA anodal tDCS over the left M1 for 20 min before the training session and practiced motor training after tDCS to improve fine motor skills. The remaining 9 subjects underwent identical training sessions, except that tDCS was artificially applied for them (sham group). Fine motor skills were assessed at baseline (pre-intervention) and after 10 sessions (post-intervention). Results: Anodal tDCS and fine motor skill training have significant effects on fine motor skills in children with ASD (P < 0.05). Conclusion: Our findings suggest that tDCS may be considered as a useful adjunct to fine motor skill training for children with ASD, although studies in a larger group of children with varying levels of autistic traits and different stimulation polarity are needed to evaluate the functional use of non-invasive brain stimulation