Spinal cord bioelectronic interfaces: opportunities in neural recording and clinical challenges

Bioelectronic stimulation of the spinal cord has demonstrated significant progress in the restoration of motor function in spinal cord injury (SCI). The proximal, uninjured spinal cord presents a viable target for the recording and generation of control signals to drive targeted stimulation. Signals have been directly recorded from the spinal cord in behaving animals and correlated with limb kinematics. Advances in flexible materials, electrode impedance and signal analysis will allow spinal cord recording (SCR) to be used in next-generation neuroprosthetics. In this review, we summarize the technological advances enabling progress in SCR and describe systematically the clinical challenges facing spinal cord bioelectronic interfaces and potential solutions, from device manufacture, surgical implantation to chronic effects of foreign body reaction and stress-strain mismatches between electrodes and neural tissue. Finally, we establish our vision of bi-directional closed-loop spinal cord bioelectronic bypass interfaces that enable the communication of disrupted sensory signals and restoration of motor function in SCI.

Automated summary

Bioelectronic stimulation of the spinal cord has made significant progress in restoring motor function in spinal cord injury (SCI). The recording and generation of control signals from the uninjured spinal cord has been achieved, allowing for targeted stimulation. Technological advances in flexible materials, electrode impedance, and signal analysis have improved spinal cord recording (SCR) for future neuroprosthetics. This review summarizes these advances and addresses the clinical challenges of spinal cord bioelectronic interfaces and potential solutions, from device manufacture to chronic effects of foreign body reaction and electrode compatibility issues. Additionally, the review presents the vision of a bi-directional closed-loop spinal cord bioelectronic bypass interface for restoring motor function in SCI cases.