Cerebellar transcranial direct current stimulation improves adaptive postural control

Abstract Objective Rehabilitation interventions contribute to recovery of impaired postural control, but it remains a priority to optimize their effectiveness. A promising strategy may involve transcranial direct current stimulation (tDCS) of brain areas involved in fine-tuning of motor adaptation. This study explored the effects of cerebellar tDCS (ctDCS) on postural recovery from disturbance by Achilles tendon vibration. Methods Twenty-eight healthy volunteers participated in this sham-ctDCS controlled study. Standing blindfolded on a force platform, four trials were completed: 60 sec quiet standing followed by 20 min active (anodal-tDCS, 1 mA, 20 min, N=14) or sham-ctDCS (40 sec, N=14) tDCS; three quiet standing trials with 15 sec of Achilles tendon vibration and 25 sec of postural recovery. Postural steadiness was quantified as displacement, standard deviation and path derived from the center of pressure (COP). Results Baseline demographics and quiet standing postural steadiness, and backwards displacement during vibration were comparable between groups. However, active-tDCS significantly improved postural steadiness during vibration and reduced forward displacement and variability in COP derivatives during recovery. Conclusions We demonstrate that ctDCS results in short-term improvement of postural adaptation in healthy individuals. Significance Future studies need to investigate if multisession ctDCS combined with training or rehabilitation interventions can induce prolonged improvement of postural balance.