Safety And Preliminary Efficacy Of Cathodal Transcranial Direct Current Stimulation To Enhance Upper Limb Motor Function Early After Ischemic Stroke: A Double-Blind, Randomized Clinical Trial

Introduction: Transcranial direct current stimulation (tDCS) has the potential to improve upper limb motor outcomes after stroke. Objective: To evaluate the safety and preliminary efficacy of active cathodal compared to sham tDCS of the primary motor cortex of the unaffected hemisphere (ctDCSM1 UH ), within 72 hours to 6 weeks post-ischemic stroke. Methods: In this randomized, double-blind study, 30 patients with unilateral hand paresis were assigned to either active or sham ctDCSM1 UH as add-on interventions to rehabilitation. The primary outcome was the frequency of adverse events. Secondary outcomes, compared before, immediately after treatment and three months later, included measures of upper limb motor performance and quality of life. Stroke volume was assessed before and after treatment. Results: Overall, tDCS was well tolerated and there were no serious adverse events. One subject in the active group reported paresthesias in the paretic arm during the first session of ctDCSM1 UH . Heart rate increased significantly after active and decreased significantly after sham ctDCSM1 UH but these changes were not clinically significant. Upper limb motor impairment and quality of life improved significantly more in the sham than in the active group at three months post-treatment according to intention-to-treat and per-protocol analyses. The between-group difference in motor impairment was not clinically relevant. There were no recurrent strokes and lesion volumes did not increase significantly in either group. Conclusions: Active ctDCSM1 UH was safe and well tolerated but the preliminary efficacy results do not support a beneficial role of this intervention within the first six weeks after stroke.