New research shows electrode devices implanted along spinal cord enables paralyzed individuals to walk independently and to feel again
Scientists have been working on spinal cord stimulation as a means of overcoming paralysis for over 30 years. While there has been some limited success in the past, this research was innovative as it used redesigned technology originally applied to alleviate pain to successfully target nerve roots. When turned on, the device makes it possible for patients suffering from paralysis resulting from severe spinal cord damage to take their first steps since their injury.
Epidural electrical stimulation (EES) which targets the dorsal roots of lumbosacral segments has been shown to restore the ability to walk in patients with spinal cord injury (SCI). This procedure was originally conducted through the use of multielectrode paddle leads originally designed to target the dorsal column of the spinal cord.
Previous evaluation of this method showed that it successfully helped paralyzed individuals redevelop the ability to stand, walk independently on a treadmill and to walk overground with a walker and body weight support after 43 weeks of multimodal rehabilitation therapy. These results were remarkable as the high-intensity training was found to cause changes that led to improved sensory-motor function even when the stimulator was not turned on. This type of improvement was unprecedented and found to occur without negative secondary side-effects.
The current study was conducted as part of the same ongoing feasibility study of Stimulation Movement Overground (STIMO) procedures. The treatment combines two intervention modalities which are “precise epidural electrical stimulation of the spinal cord” and “robot-assisted locomotion (walking training).
This method improves on the previous procedure through the use of a computational system that allows for the best possible arrangement of electrodes on a new type of paddle lead for targeting specific muscles. Electrodes targeted the dorsal roots of nerves involved in leg and trunk movement. Additionally, new software was developed which supported the rapid construction of specific activity related stimulation systems that replicated the natural activation of motor neurons responsible for each activity. It was hypothesized that this more advanced technology would lead to a quicker response and more diverse motor functions in the treated individuals.
Three patients with complete sensorimotor paralysis were treated. Within a single day of surgery, all three subjects were able to stand, walk, cycle, swim and control trunk movements. After three to four months of neurorehabilitation, there was enough improvement for these individuals to be able to engage in these activities in community settings.
One of the study participants, Michel Roccati, who was injured in a 2017 motorcycle accident in 2017 said that with the electrical stimulation is turned on he is able to walk, bike, swim and climb stairs. He added, “"Everything I have in mind to train, I can do with the stimulation."
The researchers hope these results could lead to the development of a commercially available product for tens of thousands of people with paralysis around the world in just a few years.