Effect of non-invasive brain stimulation on lower limb function in patients after stroke: A prisma-compliant systematic review and meta-analysis

Abstract

Background: In recent years, it is reported that non-invasive brain stimulation [including transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS)] could improve lower limb function in patients after stroke. However, some studies showed no effect. In the present study, we aimed to make a meta-analysis to assess effect of non-invasive brain stimulation on lower limb function in patients after stroke. Methods: Studies exploring the effect of tDCS or rTMS on lower limb function in patients after stroke were searched on the PubMed, Web of Science, EMBASE, Medline, Google Scholar before March 2021. Meta-analysis was made to summarize results of these studies. Results: The present study showed significantly better walking speed, mobility and muscle strength increase effect in tDCS group compared to sham tDCS group [walking speed: standard mean difference (SMD) = 1.14, 95% CI = 0.48 to 1.80, I2 = 74.0%, p value for Q test < 0.001; mobility: SMD = 0.79, 95% CI = 0.21 to 1.36, I2 = 53.8%, p value for Q test = 0.043; muscle strength: SMD = 2.79, 95% CI = 0.61 to 4.98, I2 = 93.9%, p value for Q test < 0.001]. In addition, meta-analysis showed significantly better walking speed, balance and motor function increase effect in rTMS group compared to sham rTMS group [walking speed: SMD = 3.31, 95% CI = 1.38 to 5.24, I2 = 92.1%, p value for Q test < 0.001; balance: SMD = 3.54, 95% CI = 1.45 to 5.63, I2 = 95.4%, p value for Q test < 0.001; motor function: SMD = 1.65, 95% CI = 0.53 to 2.76, I2 = 90.3%, p value for Q test < 0.001]. Conclusions: This meta-analysis suggested that non-invasive brain stimulation improved lower limb function in patients after stroke. More large scale, blinded RCTs were necessary to confirm the effect of rTMS and tDCS on lower limb function in patients after stroke.