Effects of Repetitive Transcranial Magnetic Stimulation Over Trunk Motor Spot on Balance Function in Stroke Patients

Abstract

Objective: To assess the efficacy of high-frequency repetitive transcranial magnetic stimulation (rTMS) on balance function in patients with chronic stroke.

Methods: Thirty participants with chronic stroke were enrolled in this study. High frequency (10 Hz) rTMS was delivered with butterfly-coil on trunk motor spot. Each patient received both real and sham rTMS in a random sequence. The rTMS cycles (real or sham) were composed of 10 sessions each, administered over two weeks, and separated by a 4-week washout period. Balance function was measured by Berg Balance Scale and computerized dynamic posturography to determine the effect of rTMS before and one day after the end of each treatment period, as well as at a 1-month follow-up.

Results: The balance function was significantly improved after high frequency rTMS as compared with that after sham rTMS (p<0.05). There was no serious adverse effect in patients during the treatment period.

Conclusion: In the chronic stroke patients, high frequency rTMS to the trunk motor area seems to be a helpful way to improve balance function without any specific adverse effects. Further studies are needed to identify the underlying mechanism and generate a detailed protocol.

Keywords: Hemiplegia; Postural balance; Stroke; Transcranial magnetic stimulation.

Fig. 1. Experimental design. For both groups, 10 real rTMS treatment and 10 sham rTMS treatment were performed within 2 weeks, separated by 4 weeks wash out period. T, time of evaluation; rTMS, repetitive transcranial magnetic stimulation.

Fig. 2. Changes in sensory organization test (SOT) scores in accordance with treatment sequence (black diamonds, real-sham treatment; gray squares, sham-real treatment). In both groups, SOT score significantly improved after real treatment and improvement persisted for 1 month after treatment.

Fig. 3. The percentage improvement in clinical measures. (A) SOT, significant improvement at the end of treatment as well as at follow-up. Other clinical measures also showed similar results. (B) On-axis velocity left-right, (C) on-axis velocity front-back, (D) DCL left-right, and (E) DCL front-back. SOT, sensory organization test; DCL, directional control. ^*p<0.05.