• MI-BCI training significantly improves upper limb motor function and daily living activities in stroke patients.
• Intervention duration ≥4 weeks and frequency ≥20 sessions yield greater improvements in daily living ability and motor function.
• MI-BCI enhances neuroplasticity and motor recovery by decoding motor imagery signals.
• Current evidence is limited by methodological heterogeneity and small sample sizes, necessitating larger, rigorous RCTs.