The discovery achieved by a group of French-speaking Swiss neuroscientists and clinicians (Courtine and Bloch Professors) is the latest achievement to understand and deal with spinal cord injuries that cause patients to stay in wheelchairs throughout the their lives. Thanks to a combination of advanced technologies that provide electrical stimulation directly to the spinal cord and intensive physical therapy, people with spinal cord injuries begin to walk.
What is different from previous studies?
Two recent studies have restored movement to paralyzed or partially paralyzed patients by applying continuous electrical stimulation to the spinal cord.
The new report by the prestigious journal Nature is the first demonstration of discontinuous stimulation: an implant sends bursts of targeted stimulation to the spinal cord, which in turn stimulates the muscles that are intended to move. Indeed, excitation may roughly mimic the signaling mechanism in the body.
Treatment is still experimental and its effectiveness for other patients with complete or partial paralysis remains to be determined. All three patients in the Swiss study felt a sensation on their feet before starting the test. There followed months of intensive training to make their first difficult steps. They still rely on wheelchairs. two can go out using a walker.
Is there sufficient electrical stimulation?
In all these recent studies, complete and prolonged recovery was necessary for success. Participants attended 100 to 278 sessions combining stimulation and recovery for a period of 5 to 21 months. Thus, only electrical stimulation was not the "magic sphere".
How did the studies begin?
The authors of the new report had previously shown that rats who had lost their hind legs could be trained to function again when a continuous stream was applied to their muscles through the spinal cord.
However, in humans, continuous stimulation seems to send a mixed signal to the muscles, triggering some and confusing others. For this reason, electrical excitation explodes appear to be more successful in these three patients with less severe spinal cord lesions.
What is the mechanism?
One of the fascinating discoveries was that each of the three patients learned to move previously soft muscles without the help of the implant. Perhaps electrical stimulation has caused the recovery of the nerves that are saved from the injury.
What's the future?
More participants need to be tested and may need new excitation techniques for various types of injuries. In any case, Courtine's team at EPFL reinforces the brilliant future of treating spinal cord injuries.