Anodal tDCS: A Promising Tool for Enhancing Balance in Children with ASD

In a randomized, double-blind trial, anodal tDCS added to structured neuro-rehabilitation produced large, durable improvements in balance for children with autism spectrum disorder (ASD) compared with rehabilitation alone.

Motor dysfunction and impaired postural control are common in pediatric ASD and often limit everyday participation. Standard care emphasizes targeted neuro-rehabilitation and balance training, but gains are variably durable; the investigators tested whether adding focal cortical stimulation would enhance motor learning and retention.

The trial randomized 60 children (aged 6–17 years) in a double-blind, sham-controlled design to active stimulation plus individualized neuro-rehabilitation or to sham plus the same rehabilitation. Stimulation targeted the primary motor cortex with the cathode over the right supraorbital area. Primary endpoints were the MABC-2 balance subscale and the Quick Neurological Screening Test (QNST), assessed at baseline, immediately after 10 sessions (5/week for 2 weeks), and at 2-month follow-up. The rehabilitation program delivered individualized, balance-focused exercises immediately after each stimulation session.

Active tDCS plus rehabilitation produced large, statistically significant gains on the MABC-2 balance subscale: post-intervention percentiles were 67.33 ± 34.08 for the active group versus 17.27 ± 23.70 for sham (p=0.0001), with a maintained advantage at 2 months (64.89 ± 31.04 vs 8.20 ± 6.84; p=0.0001). On the QNST (higher scores = greater impairment), the active arm moved into the within‑normal range post-intervention (mean 7.46 ± 3.59) and remained substantially improved at follow-up (mean 12.20 ± 9.90), whereas the rehabilitation-only arm showed only small, non-sustained shifts (post 24.71 ± 9.24; follow-up 26.93 ± 10.00). The between-group percent-change—calculated as (follow-up − baseline)/baseline × 100%, so negative values indicate reduced impairment—favored stimulation by roughly an order of magnitude (group mean change ≈ −61.11% vs −6.99%). These findings indicate both immediate and durable functional balance gains with stimulation in this cohort.

Stimulation parameters are clearly specified and reproducible: anodal tDCS over the primary motor cortex, 1 mA, 20 minutes per session with 30-second ramp up/down, delivered in 10 sessions over two weeks. Adverse events were mild and transient: tingling under the electrodes in 13.3% of children, caregiver‑reported irritability in 10%, and brief sleepiness in 3.3%—all resolved by the fourth day/session. Overall the regimen was well tolerated in this pediatric sample.

Combined tDCS and targeted neuro-rehabilitation shifts the treatment calculus by producing larger and more durable motor gains than rehabilitation alone in this trial, but important limits remain: a single-center sample, modest size (n=60), and a 2‑month follow-up that does not establish long-term durability. Replication in larger, multicenter cohorts, standardized stimulation and rehabilitation protocols, and longer-term outcome assessment are needed before routine clinical implementation.