Transcranial Direct Current Stimulation Combined With Virtual Reality for Balance and Executive Function in Children With Spastic Diplegic Cerebral Palsy: A Three-Arm Randomized Controlled Trial

Introduction:
Children with spastic diplegic cerebral palsy often have poor executive functioning and balance. In virtual reality (VR) rehabilitation, some studies have suggested that transcranial direct current stimulation (tDCS) could be beneficial for improving learning. The purpose of this study was to find out if the combination of active tDCS and VR is superior in enhancing balance and executive function compared to sham tDCS and VR or conventional therapy.

Methods:
A total of 42 children (aged 8–16 years) with GMFCS levels I–III were randomly divided into three groups: Active tDCS and VR, sham tDCS and VR, and conventional therapy. There were 18 sessions, which took place over 6 weeks. During VR training, active tDCS was administered at 1 mA for 20 minutes, and sham for 30 s. The assessments were conducted at baseline, session 9 and session 18. Linear mixed-effects models were used to test group by assessment interactions, adjusted for covariates and corrected using Holm.

Results:
There was a significant group x assessment interaction for the peds BSA scores (adjusted p=0.043). The difference between the change rates of active tDCS plus VR and conventional therapy was statistically significant (1.0 point; 95% CI, 0.418–1.582; adjusted p=0.007), but not between the change rates of sham tDCS plus VR and conventional therapy (0.5 point; 95% CI, −0.082 to 1.082; adjusted p=0.647). Not all sensitivity analyses were consistent. There were no differential effects on the Functional Reach Test distance, Digit Span total score, Trail Making Test Part B or Stroop interference time (all adjusted p=1.000).

Conclusions:
Active tDCS plus VR resulted in better functional balance than conventional therapy, but failed to reliably demonstrate an effect on executive function. Improvements in balance may be more attributed to VR than to simultaneous tDCS.