May Dual Transcranial Direct Current Stimulation Enhance the Efficacy of Robot-Assisted Therapy for Promoting Upper Limb Recovery in Chronic Stroke?

The main between-group comparison was null, so positive claims rest on secondary or post-hoc findings. The motor evoked potential subgroup analysis was not planned before treatment, so it cannot be treated as confirmatory. There was no control group receiving the same amount of conventional non-robotic therapy, so improvement cannot be assigned to the robot rather than usual rehabilitation. Follow-up was incomplete: 66 of 80 enrolled patients completed the rehabilitation pathway, and 50 were assessed at both planned follow-ups. The sample was chronic stroke patients with stable upper limb deficits and excluded completely paralyzed limbs, severe neglect, epilepsy, and other conditions, so results may not apply to patients outside those criteria. The robot-measured range-of-motion increase did not match a significant clinical between-group difference on the primary outcome.

The authors declared no potential conflicts of interest with respect to the research, authorship, and publication of the article.

Do not read the higher percentage gain in patients without motor evoked potentials as proof that dual tDCS helps that subgroup. That split was post-hoc, and the direct comparison of Fugl-Meyer scores between real and sham tDCS in those patients was not significant.