Repetitive Transcranial Magnetic Stimulation for Motor Recovery After Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials With Low Risk of Bias

Abstract

Objectives: Repetitive transcranial magnetic stimulation (rTMS) has shown promising results in enhancing motor recovery after stroke, but nuances regarding its use, such as the impact of the type and site of stimulation, are not yet established. We aimed to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) with low risk of bias to investigate the effect of rTMS on motor recovery after both ischemic and hemorrhagic stroke.

Materials and methods: Three databases were searched systematically for all RCTs reporting comparisons between rTMS (including theta-burst stimulation) and either no stimulation or sham stimulation up to August 19, 2022. The primary outcome measure was the Fugl-Meyer Assessment for Upper Extremity (FMA-UE). Secondary outcome measures comprised the Action Research Arm Test, Box and Block Test, Modified Ashworth Scale for the wrist, and modified Rankin Scale (mRS).

Results: A total of 37 articles reporting 48 unique comparisons were included. Pooled mean FMA-UE scores were significantly higher in the experimental group than the control group after intervention (MD = 5.4 [MD = 10.7 after correction of potential publication bias], p < 0.001) and at the last follow-up (MD = 5.2, p = 0.031). On subgroup analysis, the improvements in FMA-UE scores, both after intervention and at the last follow-up, were significant in the acute/subacute stage of stroke (within six months) and for patients with more severe baseline motor impairment. Both contralesional and ipsilesional stimulation yielded significant improvements in FMA-UE at the first assessment after rTMS but not at the last follow-up, while the improvements from bilateral rTMS only achieved statistical significance at the last follow-up. Among the secondary outcome measures, only mRS was significantly improved in the rTMS group after intervention (MD = -0.5, p = 0.013) and at the last follow-up (MD = -0.9, p = 0.001).

Conclusions: Current literature supports the use of rTMS for motor recovery after stroke, especially when done within six months and for patients with more severe stroke at baseline. Future studies with larger sample sizes may be helpful in clarifying the potential of rTMS in poststroke rehabilitation.

Keywords: Neuromodulation; brain stimulation; rehabilitation; stroke; transcranial magnetic stimulation.