A system developed by researchers at the Ecole Polytechnique Fédérale de Lausanne (EPFL) allows patients with a complete spinal cord injury to stand up, walk and even engage in recreational activities such as swimming, cycling or canoeing.
It’s about the personalized electrical stimulation of the spinal cord using electrode plates specifically designed for spinal cord injuries. In a study published today in Nature Medicine, this innovative technique has been shown to restore independent motor movements within hours of initiation of therapy in three patients with complete sensorimotor paralysis.
spinal cord injuries interrupt communication within the nervous system, leading to loss of essential neurological functions and leading to paralysis.
Electrical epidural stimulation, that is, stimulation applied to the spinal cord, had been successful in restoring locomotor ability in animal models of spinal cord injury, but until now had been less effective in humans for unknown reasons.
In 2019 the team of Gregoire Courtine, from the Ecole Polytechnique Fédérale de Lausanne (EPFL) in collaboration with the Jocelyne Bloch, from the University Hospital of Lausanne, both in Switzerland, applied this therapy to three patients who had different types of spinal cord injury: chronic spinal cord injury and partial or complete paralysis of the lower extremities. Within a week all three could walk with crutches.
This was the first proof that their therapy, which uses electrical stimulation to reactivate spinal neurons, could work effectively in patients.
Now the team led by Courtine y Bloch it has upgraded its system with more sophisticated implants controlled by artificial intelligence software.
The new implants, they explained, can stimulate the region of the spinal cord that activates the muscles of the trunk and legs.
Thus, thanks to this new technology, three patients with paraplegics have not only walked again, but have taken another step. “Our algorithms for stimulation mimic nature,” explains Courtine. And our malleable implanted wires have been designed to be placed under the vertebrae, directly over the spine, making it possible to modulate neurons that regulate specific muscle groups.”
Courtine explains that “by controlling these implants, it is possible to activate the spinal cord as the brain would naturally so that the patient gets up, walks, swims, or rides a bike».
The Italian Michael Roccati He was one of the three lucky ones to be able to walk on their own again last December. Four years earlier, Michel had suffered a serious motorcycle accident that left him a paraplegic in a wheelchair.
Days after undergoing the surgical procedure in which surgeon Bloch implanted the new cable in his spinal cord, Michel, together with experts from the Courtine and Bloch research center, took to the streets of Lausanne to try out his new life.
Michel’s walker had two small remote controls that connected wirelessly to a tablet that sends signals to a pacemaker in Michel’s abdomen. The pacemaker, in turn, transmits the signals to the wire located in the spinal column and stimulates specific neurons, causing Michel to move.
So, Michel took his walker and set off. He himself pressed the button on the right side of the walker to step forward with his left leg. His left foot lifted as if by magic and landed on the ground a few inches ahead. He then did the same with the button on his left side, and his right foot moved forward. I was walking!
“The first steps were incredible, a dream come true! -recognize-. I’ve been through some pretty intense training over the last few months, and I’ve set myself a number of goals. For example, now I can go up and down the stairs, and next spring I hope to be able to walk a kilometer.”
Two other patients have also successfully tried the new system. And all this in just 24 hours.
“All three patients were able to stand, walk, cycle, swim and control their movements just one day after their implants were activated,” Courtine notes.
“Our great avance are the implanted leads, longer and wider, with electrodes arranged in a manner identical to spinal nerve roots,” explains Bloch. This gives us precise control over the neurons that regulate specific muscles.”
In addition, this sophisticated wiring system with electrodes allows greater selectivity and precision in the control of motor sequences for each activity: walking, cycling, swimming…
“Thanks to the specific stimulation programs for each type of activity, patients can select the desired activity on the tablet and the corresponding protocols are transmitted to the pacemaker in the abdomen,” he adds.
Also, while it’s amazing how quickly the therapy works, profit increases over time.
The researchers write that months later the three patients, who followed a training regimen based on stimulation programs allowing them to regain muscle mass, they could move more independently and participate in social activities such as having a drink standing up in a bar.
Another detail is that all the training can be done outdoors, and not just inside a laboratory, thanks to the fact that the technology is miniaturized.
The next step, Courtine concludes, “turning our discoveries into treatments that can improve the lives of thousands of people around the world.”
And how far can this technique go? Courtine believes that technological advances are going to help a lot. “Next generations of electrodes will be more precise and better able to activate the concise areas.”
In this sense, they are working with the ONWARD Medical biotechnology company to develop customized neurotechnology with the aim of turning this rehabilitation paradigm into a treatment available in hospitals and clinics around the world. “We are building next-generation neurotechnology that will also be tested closer to the time of injury, when the potential for recovery is high and the neuromuscular system has not yet undergone the atrophy that follows chronic paralysis. Our goal is to develop an easily accessible treatment,” adds Courtine.
Like other approaches, this technology does not generate new neurons and does not regenerate nerves. In animals, Courtine noted, “what we’ve seen is that neural connections in the cortex are rearranged. The treatment achieves this new brain connection, although in humans it is still a hypothesis.