New spinal cord implants are helping paraplegic patients walk or regain some movement, with the results documented in two new studies this week. The device electrically stimulates the spinal cords of patients that lost voluntary movement below the site of an injury. Along with physical training, two teams of scientists are now reporting success with the device, according to The Guardian.
One team, at the Kentucky Spinal Cord Injury Research Center at the University of Louisville published a study in the New England Journal of Medicine. They implanted 16 electrodes in the lower back of four paralyzed patients, below the site of their injury, over areas that send signals to the legs. A battery was separately implanted in the abdominal wall, allowing the stimulation to be controlled wirelessly. This epidural stimulation relies on small signals that still make it past the site of a spinal cord injury. The stimulation helps to make the spinal cord more receptive to signaling.
“It is like it is more aware, it actually can listen to that little whisper from the brain that is still there and it can generate the motor pattern,” says Dr Claudia Angeli, one of the study’s authors.
Of the four patients, two were ultimately able to walk without assistance. The other patients were able to stand and sit without help.
Another study published in Nature Medicine, by researchers from UCLA and the Mayo clinic, showed similar success with the approach. With training, a paralyzed patient was able to walk without assistance on a treadmill, and across ground with a frame and some human assistance.
Dr. Kendall Lee, of the Mayo Clinic, explained:
“The patient’s own mind, or thought, was able to drive the movement in the legs. You have to deliver a very specific type of stimulation parameters. A random stimulation does not work.”
Angeli also noted that it takes time and special programming to get results from the implants. She said that if the intensity of the stimulation is too high, it can lead to involuntary movements, but too low, and signals won’t get through at all.
“A future direction that we are actually starting right now is to see if we target the epidural stimulation for [the] bladder itself, if we can actually improve the bladder control,” Angeli said.
Other experts praised the results, but said the technique could be honed to produce more robust muscle movements.