Brain-computer interface for upper limb functional recovery post-stroke: a meta-analysis of improvement in upper limb motor function and changes in neurophysiological markers.

backgroundBrain-Computer Interface (BCI) has emerged as a promising intervention, facilitating recovery of upper limb motor function, enhancing associated neurophysiological markers, and improving activities of daily living (ADL) performance, which is measured using the Modified Barthel Index (MBI). Nevertheless, most existing research has centered on individual outcome domains, and thus critical questions remain unanswered. These questions include heterogeneity in treatment efficacy across different post-stroke phases, in addition to the consistency of BCI's effects across specific functional assessment scales, such as the Fugl-Meyer Upper Extremity Scale (FMA-UE) and the Action Research Arm Test (ARAT)-and on neurophysiological markers.

objectiveTo perform a systematic review and meta-analysis of the effects of BCI-mediated rehabilitation versus conventional rehabilitation on upper limb motor function, functional activities, neurophysiological markers, and MBI performance in patients with stroke.

methodsSystematic searches were performed in 7 databases for this study: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Wan Fang Data, and China Biology Medicine Database (CBM). Inclusion criteria were randomized controlled trials (RCTs) comparing BCI-mediated rehabilitation with conventional rehabilitation in patients with upper limb dysfunction following stroke. The primary outcome measure was FMA-UE scores. Secondary outcome measures included functional activity levels as assessed by ARAT, neurophysiological markers (e.g., motor evoked potentials, MEPs, electroencephalography, EEG indices), and MBI scores. The methodological quality of the included studies was assessed using the validated evidence-based Cochrane Collaboration's RoB 2.0. In the meta-analysis, if the results of the heterogeneity test were less than 25%, the fixed-effect model was employed; otherwise, the random-effects model was used. For each outcome measure, the mean difference (MD) or standardized mean difference (SMD), together with their corresponding 95% confidence intervals (95% CI), were calculated.

resultsAfter screening against the inclusion and exclusion criteria, 16 eligible randomized controlled trials (RCTs) were ultimately included, encompassing a total of 1761 patients. Compared with conventional rehabilitation interventions, BCI rehabilitation interventions exert a certain effect on improving patients 'upper limb motor function (SMD = 0.49, 95%CI;0.26-0.73, p = 0.037).Additionally, significant improvements were observed in ARAT scores (SMD = 0.53, 95% CI: 0.14-0.91, p = 0.035),neurophysiological markers(SMD = 0.53, 95% CI;0.08-0.98, p < 0.05)and MBI scores(SMD = 0.85, 95% CI;0.55-1.14, p < 0.001).Subgroup analyses of BCI-mediated rehabilitation interventions for upper limb motor function recovery in stroke patients demonstrated certain subgroup-specific disparities in the magnitude of therapeutic effects across different subgroups. With respect to stroke staging, BCI-mediated rehabilitation interventions conferred superior efficacy for motor function recovery in patients with subacute stroke, a finding plausibly attributable to the temporal course of post-stroke neural remodeling. Subgroup analyses stratified by intervention dosage demonstrated that both 10-15 and 20-30 sessions of BCI-mediated rehabilitation interventions resulted in clinically meaningful improvements in patients' upper limb function. No statistically significant difference was detected between these two treatment regimens, yet the 20-30-session protocol was associated with a relatively larger effect size. Furthermore, subgroup analyses stratified by intervention modality demonstrated that no statistically significant differences emerged across the distinct intervention approaches, and this observation plausibly suggests the rehabilitative benefits of divergent BCI paradigms in patients are uniformly mediated through neural circuit remodeling.

conclusionBCI emerges as a promising therapeutic modality for stroke rehabilitation, delivering substantial, statistically significant improvements across multiple key outcomes, including FMA-UE, ARAT, neurophysiological markers, and MBI scores with consistent statistical significance observed across all aforementioned domains.