Therapeutic Effects of Diagonal-Transcranial Direct Current Stimulation on Functional Recovery in Acute Stroke: A Pilot Study

Abstract Background: Peak neurologic recovery from acute stroke occurs within the first 3 months, and continues at a slower pace for 6 months. Objective/Hypothesis: The aim of this pilot study is to clarify the safety and feasibility of multiple diagonal-transcranial direct current stimulation (d-tDCS) sessions up to 3 months with electrodes placed diagonally over the lesional dorsolateral prefrontal cortex and contralesional primary motor cortex for upper limb hemiparesis in acute stroke. Methods: Five patients with acute stroke (2 with intracerebral hemorrhage and 3 with cerebral infarction) with upper limb paresis participated. d-tDCS (1 mA, 20 min per day) combined with conventional rehabilitation was given starting 7–21 days after stroke onset. Each session consisted of 10 d-tDCS over 2 weeks and patients received 2 sessions in the acute phase and 2 sessions in the subacute phase for a total 40 treatments. Motor function was assessed using Fugl-Meyer Assessment for upper extremity (FMA-UE) before and after each session, and the period to achieve 70% of maximal potential recovery in FMA-UE was evaluated. Results: All 5 patients completed the intervention and showed no adverse effects throughout the protocol. Of these, 3 (60%) achieved 70% predicted scores within 2 months. Regarding therapeutic gains of FMA-UE in each of the 10 sessions in the acute phase, 4 sessions showed great recovery, 3 sessions showed moderate recovery, and 3 sessions showed poor recovery. Conclusion: These findings suggest that d-tDCS over 3 months may be safe and feasible for acute stroke patients in the acute to subacute phases and have therapeutic potential to promote recovery of upper limb function, although further randomized, double-blind, sham-controlled trial is warranted with larger sample size.