Effectiveness of a combined transcranial direct current stimulation and virtual reality-based intervention on upper limb function in chronic individuals post-stroke with persistent severe hemiparesis: a randomized controlled trial.

Only 29 participants were analysed, after one control participant attended only one session and two experimental participants dropped out. The trial was registered retrospectively, after the study period. The experimental group received tDCS and a VR task plus conventional physical therapy, and no sham tDCS or placebo VR was used, so the contribution of any single component cannot be separated. The supervising physical therapist was not blinded, although the outcome assessor was blinded. The trial measured outcomes only before and after the intervention, so it does not show whether motor gains persisted. The study had no structural or functional data on corticospinal tract integrity, so it cannot explain why four participants did not improve. The Wolf Motor Function Test gains had poor effect sizes, so those secondary motor activity findings were weaker than the primary Fugl-Meyer result.

Funded by Conselleria d'Educació, Investigació, Cultura i Esport, Ministerio de Economía y Competitividad, and Universitat Politècnica de València (ES). The supplied text lists these funders and does not state author conflicts.

Do not conclude that tDCS or VR alone caused the motor gains. The experimental group also received conventional physical therapy, and no sham tDCS or placebo VR was used, so the contribution of any single component cannot be separated.