Electrical and optogenetic spinal cord stimulation for movement recovery after spinal cord injury

In this review, we discuss electrical and optogenetic technologies for stimulating the spinal cord to improve movement after spinal cord injury (SCI).

Paralysis or paresis following SCI severely impairs control and movement of the extremities. Restoring movement in the upper and lower extremities is a top priority for this population. Invasive and noninvasive electrical stimulation of the spinal cord can modulate the activity of spinal circuits, resulting in improvements in motor and sensory function. More recently, optogenetic stimulation has emerged as another technique capable of modulating spinal circuity to facilitate movement recovery in animal models. Recent studies are offering new insights into the effects of parameter selection, multisite stimulation, and the combined effects of stimulation and wearable robotic exoskeletons, all with the goal of restoring movement after SCI.

Modulating the activity of the spinal cord via electrical and optogenetic stimulation is a promising intervention for improving movement after SCI. Future studies should determine optimal stimulation parameters, synergistic effects when combined with wearable robotics, and the safety of optogenetics in the human spinal cord. Such work will best position these emerging technologies for clinical translation.