Brain-spine interface: an exploration of a potential future treatment for spinal cord injury

Spinal cord injuries (SCIs) profoundly impact millions globally, leading to loss of motor and sensory functions below the injury site. Brain-spine interfaces (BSIs) represent an early-stage neuroprosthetic strategy that attempts to restore functional communication between cortical motor-intention signals and spinal sensorimotor circuits below the level of injury. Although early preclinical and highly selected clinical studies have shown encouraging motor outcomes, the evidence remains preliminary, and routine clinical use is limited by questions regarding safety, durability, patient selection, accessibility, and long-term functional benefit. BSI approaches are based on the observation that residual spinal pathways and sensorimotor circuits may remain partially responsive to neuromodulation even after injury. Along the way, technological advancements have significantly bolstered SCI treatment strategies, ranging from surgical interventions to regenerative therapies. Approaches such as neurostimulation and biomaterial-based strategies have shown potential in experimental and early translational settings, although their clinical efficacy and generalizability remain incompletely established. Furthermore, exploring neuroplasticity and the body's intrinsic ability to reorganize neural connections post-injury underscores the potential for spontaneous recovery in certain cases. However, integrating BSIs into clinical practice faces substantial hurdles, including technical challenges, ethical considerations, and the need for specialized training for healthcare providers. Despite these obstacles, BSIs and other novel treatments may have potential to improve the quality of life for SCI patients, although further clinical investigation is needed to establish their safety, efficacy, and generalizability. This review catalogs recent conceptual and technological developments contributing to the emergence of BSI.