Conclusion

Spinal cord injury treatment has progressed from supportive care and surgical stabilization toward increasingly sophisticated strategies that seek to preserve neural tissue, modulate residual circuits, promote plasticity, and restore functional movement. BSIs represent a promising engineered neuroprosthetic approach that attempts to bridge disrupted communication between cortical motor-intention signals and spinal sensorimotor circuits below the level of injury. However, BSIs should not be interpreted as a natural reconnection of the brain and spine, nor are they ready for routine clinical use. Current BSI evidence remains early-stage and is largely derived from preclinical studies, proof-of-concept systems, small cohorts, and highly selected participants. Important limitations include patient selection, invasiveness, surgical and device-related risks, long-term safety, decoding stability, durability of benefit, rehabilitation intensity, cost, accessibility, and uncertain generalizability across the broader SCI population. Future studies will need to establish whether BSI-mediated gains are reproducible, durable, clinically meaningful, and achievable outside specialized research settings. Thus, while BSIs may become an important component of future SCI rehabilitation, their promise must be balanced against the substantial technical, clinical, ethical, and logistical barriers that remain.