Protocol of Non-invasive Current Stimulation in Acute Posterior-circulation Stroke with High Risk for Falling (NAPS trial): A Randomized Double-blind Sham-controlled Study

Abstract Background: Posterior-circulation stroke accounts for approximately 20∼30% of all ischemic stroke. It can manifest as symptoms with a variety of headache, nausea, diplopia, ataxia and gait disturbance. Among them, imbalance and gait problem are main symptoms that can induce a difficulty for living daily life and a high risk for falling in these patients. In many neurological diseases including stroke and cerebellar ataxia, a therapeutic approach to imbalance and gait problem through brain stimulation has received much attention at neurorehabilitation field. However, there has been no such effort focusing on acute posterior-circulation stroke patients with imbalance and/or gait problem. Our study’s aim is to investigate the effect of non-invasive repetitive transcranial direct current stimulation (tDCS) of cerebellum on improving balance/gait control in acute posterior-circulation stroke patients with imbalance or gait problem. Methods: Acute posterior-circulation stroke patients who were admitted within 5 days of symptom onset and at high risk for falling due to imbalance and/or gait problem, were recruited and randomized into two groups: intervention (tDCS stimulation) and control (sham stimulation) groups. Intervention group will receive 10 daily sessions of tDCS for 2 weeks (2 mA for 20 min). Outcome measurement was performed at baseline, after 2 weeks (the end of stimulation), and 4 weeks. Primary outcome was mean difference of Performance-oriented assessment of mobility (POMA) total score (baseline - 4 weeks) between the two groups. Secondary outcomes were difference of the balance and gait score of POMA, Dizziness Handicap Inventory (DHI), Falls Self-Efficiency Scale (FES-I), Beck Depression Invention (BDI), Beck Anxiety Inventory (BAI) and gait analysis. Conclusion: Our study focuses on the acute-stage (<1 week of symptom onset) and more specific symptoms in posterior-circulation stroke patients to improve the clinical outcome and quality of life in those and prove the effect of early tDCS intervention. Keywords: Transcranial direct current stimulation, Acute stroke, Posterior-circulation, Outcome