Dimitry Sayenko, M.D., Ph.D.
The mammalian spinal cord can generate rhythmic or tonic motor output even in the absence of input from the brain. This evidence led to the hypothesis that if similar spinal circuits exist in humans, then electrically stimulating the lumbosacral spinal cord in combination with motor activity could facilitate motor function and mobility in patients with spinal cord injury (SCI). Adults with chronic motor complete paraplegia underwent epidural spinal stimulation therapy, could maintain minimally assisted standing, and revealed significant levels of voluntary control of the lower limbs during stimulation. Similar functional outcomes can be obtained using transcutaneous spinal stimulation. Activation of sub-functional longitudinal fibers across the lesion, and emerging responsiveness of spinal networks below the lesion to descending commands and proprioception is considered the main mechanism for both invasive and non-invasive spinal stimulation to restore function after paralysis.