Effects of combined non-invasive brain stimulation and brain-computer interface on upper extremity motor function after stroke: a systematic review and meta-analysis

Abstract

Non-invasive brain stimulation (NIBS) and brain-computer interface (BCI) training are both promising approaches for post-stroke upper extremity rehabilitation, and their combination has been hypothesized to produce synergistic effects. However, the efficacy of this combined strategy has not been systematically evaluated. We systematically searched EMBASE, PubMed, Web of Science, and the Cochrane Library from inception to October 2025 for randomized controlled trials evaluating NIBS combined with BCI in stroke rehabilitation. Mean differences (MDs) in pre- to post-intervention change scores and 95% confidence intervals (CIs) were pooled. Prespecified subgroup analyses were conducted to examine potential moderators. Seven randomized controlled trials were included. Pooled analysis showed that NIBS combined with BCI did not provide superior immediate upper extremity motor recovery compared with BCI alone and was associated with lower FMA-UE improvement (MD = −3.67, 95% CI −5.32 to −2.01; I 2  = 0%). Subgroup analysis suggested that this effect was mainly driven by studies of tDCS plus BCI, while no significant difference was observed for rTMS plus BCI. No significant long-term effect of tDCS plus BCI or stimulation-site difference for rTMS plus BCI was identified. However, the certainty of evidence ranged from moderate to very low, and sensitivity analyses suggested that the findings were unstable. Current evidence does not demonstrate a clear additional benefit of NIBS as an adjunct to BCI for upper extremity rehabilitation after stroke. Given the limited number of studies and the instability of the pooled result in sensitivity analysis, these findings should be interpreted cautiously. More rigorous and adequately powered trials are needed to determine whether optimized stimulation protocols or specific patient subgroups may benefit from this combined strategy. https://www.crd.york.ac.uk/PROSPERO/ , identifier CRD420251151708.