Effects of transcranial direct current stimulation combined with virtual reality on gross motor skills, balance and cognitive function in children with down syndrome

Abstract

Objective: Down syndrome (DS) is most common chromosomal cause of intellectual disability in children; characterized by delayed milestones, poor gross motor function (GMF), gait and balance difficulties. The aim of this study was to determine if a combination of transcranial direct current stimulation (tDCS) and virtual reality (VR) training better improve GMF, balance, and cognitive function than by conventional physiotherapy alone. Methodology: This single-blind randomized control trial, conducted at Superior University, Lahore, Pakistan, (May 2025 - October 2025), included 30 children (6-12 years) randomly assigned to Group-A (VR + tDCS, n = 15) and Group-B (conventional physiotherapy, n = 15). Children with other neurological, metabolic, cardiopulmonary, visual, or significant sensory issues, recent surgery, musculoskeletal deformities, seizures, sensitivity to electrical stimulation were excluded. Both groups received sessions over 12 weeks. Outcomes included GMFM-D and GMFM-E, balance, and cognition. Result: Both interventions showed statistically significant within-group gains from both interventions (p < 0.001). Group-A had consistently higher post-intervention scores than Group-B. Independent sample t-tests between-group difference for GMFM-D was statistically significant (p = 0.050). However GMFM-E (p = 0.105), balance (p = 0.196), or cognition (p = 0.150) did not reach statistical significance.  Large within-group effect sizes in both groups indicate substantial improvements following both interventions. Conclusion: Both groups produced significant improvements in GMF, balance, and cognition. VR+tDCS improved standing function significantly more than conventional therapy; supporting the potential role of tDCS + VR for children with DS.