For the more than one million Americans paralyzed by a spinal cord injury, the dream of standing and walking again may soon be a possibility. Scientists at the Kentucky Spinal Cord Injury Research Center at the University of Louisville have developed a combination treatment using implants to stimulate the spinal cord, along with intense physical therapy to help paralyzed patients regain motor function. The implant itself has been used for the treatment of chronic pain. Its use in spinal cord injury patients is new and still experimental.
Epidural spinal cord stimulation involves surgically implanting nerve-stimulating electrodes into the lower spine, the area that controls movement of the hips, legs and feet. To trigger the electrodes, a stimulator is implanted in the abdomen.
The initial study of the technique involved four patients who had been unable to stand, walk or sit without support for between two and three years. Two of the patients had some sensation below the level of their injury.
The patients began with two months of physical therapy called locomotor training. Their weight was supported in an apparatus while therapists moved their legs on a treadmill for two hours a day, five days a week to rehabilitate their muscles.
The next step was to surgically implant the nerve-stimulating electrodes and the abdominal stimulator. After recovering from surgery, the patients started on months of near-daily locomotor training using the apparatus while getting constant stimulation from the device. Training sessions included standing, treadmill walking and, for those who could, walking on the ground. Over time, the support from the apparatus was reduced to let the patients support more of their weight on their own.
All four patients gained some ability to move their legs, walk on the treadmill with support and stand using a walker. The two patients who had had some sensation were also able to walk on the ground, one with a walker and the other using poles or holding hands with physical trainers. Researchers believe the stimulation excites the healthy spinal cord below the level of the injury, making it receptive to information. Signals from the brain giving the intent to walk are able to cross the injury site. The spinal cord then integrates the command from the brain with sensory cues and generates the appropriate movement.
The length of time it took to reach these achievements was different for each patient, even between the two who were able to walk—it took one, a 23-year-old woman, 3.5 months and the other, a 35-year-old man, 18 months.
Overall, this research showed that the spinal cord stimulator, when combined with intense locomotor training and the intent to walk, led to the recovery of the ability to walk even years after a spinal cord injury.
With expanded research and improvements in stimulator technology, the scientists predict that more gains will be seen.
As of now, spinal cord epidural stimulation has moved into the trial phase, with a new 36-patient study supported by the Christopher and Dana Reeve Foundation under way at the University of Louisville. If you or a loved one is interested in participating in a future paralysis research trial, you can add your name to a database of potential research participants at https://victoryoverparalysis.org/participate-in-research-copy/.
