the neuroscientist Grégoire Courtine, from the Ecole Polytechnic Federal de Lausanne (EPFL), has been researching for years to get people with damaged spinal cords to walk again. Its advances in this field were demonstrated with mice in 2012 and with monkeys in 2016. Finally, in 2018, human patients arrived. On that occasion, three men paralyzed for several years walked again after presenting implants in the spinal cord.
After a few months of training with smart belts, they were able to control their leg muscles and take steps on their own, without the need for electrical stimulation. The results of this work, carried out in conjunction with the neurosurgeon jocelyne blochfrom the Centro Hospitalar Universitario EPFL de Vaud, were published in two studies in Nature is on Nature neuroscience.
The images from the end of 2018 made headlines around the world. David Mzee, who had been paralyzed by a partial spinal cord injury sustained in a sports accident, got up from his wheelchair and began to walk with the help of a walker. This was the first evidence that the Courtine and Bloch technique, which uses electrical stimulation per reactivate neuronscould work effectively in patients.
They introduced several improvements to the electrostimulation system: “The implanted electrode set is longer and wider in this version, which allows access to a greater number of nerve roots in the legs and trunk”, explains Jocelyn Bloch
Three years later, a new study led by these two experts and published in Nature medicine introduced several improvements in the injured spinal cord electrostimulation system that resulted in greater patient mobility in a shorter period of time, the authors point out.
Among these improvements, Jocelyne Bloch tells SINC that “the implanted electrode array is longer and wider in this version, which allows access to a greater number of nerve roots in the legs and trunk”.
These implants, explains Bloch, stimulate the region of the spinal cord that activates the muscles in the trunk and legs. Thanks to this technology, three spinal cord injury patients were able to walk outside the laboratory.
“Our stimulation algorithms are based on imitating nature,” says Courtine. “And the new implanted flexible electrodes are designed to be placed under the vertebrae, directly into the spinal cord. They can modulate neurons that regulate specific muscle groups.”
In addition, “by controlling these implants, we can activate the spinal cord as the brain would naturally make the patient stand up, walk, swim or ride a bicycle, for example”, he highlights.
Stimulation algorithms are based on imitation of nature. And the new implanted soft electrodes are designed to be placed under the vertebrae, directly into the spinal cord. They can modulate neurons that regulate specific muscle groups
Grégoire Courtine, neuroscientist at EPFL
Activate engine sequences with the push of a button
Last December, on a cold and snowy day, Michel Roccatti – an Italian man who was paralyzed after a motorcycle accident four years ago – braved icy winds to test the system outdoors in central Lausanne, say the authors.
He had recently undergone the surgery in which Bloch had the new cable implanted in his spinal cord.
The team at Courtine and Bloch’s NeuroRestore research center was with him, helping to put together the demonstration. They connected two small remote controls to Roccati’s walker and wirelessly connected a tablet that transmitted the signals to a pacemaker placed in his abdomen. That pacemaker, in turn, transmitted signals to the implanted spinal cord that stimulated specific neurons, causing the patient to move.
When he was ready, he grabbed the walker and left. He pressed the button on the right side of the walker, intending to step forward with his left leg. His left foot rose and fell to the ground a few inches later. He then did the same with the left button and his right foot came forward. I was walking!
“The first steps were incredible, a dream come true!” says Rocatti. “I’ve been training very intensely over the last few months and set a series of goals. For example, I can now go up and down stairs and I hope to be able to walk a kilometer this spring,” says the Italian.
The first steps were incredible, a dream come true! I’ve been training very intensely over the last few months and set a series of goals. For example, I can now go up and down stairs and hope to be able to walk a mile this spring.
Michel Roccati, patient
Two other patients also successfully tested the new system, described in natural medicine. “Our innovation in this case is longer and wider implanted electrodes with electrodes arranged to exactly match the spinal nerve roots,” insists Bloch. “This gives us fine control over the neurons that regulate specific muscles.”
Ultimately, it allows for greater selectivity and precision in controlling the motor sequences of a given activity, adds the neurosurgeon.
First steps a few hours later intervention
The researchers note that an extensive training program is obviously necessary for patients to feel comfortable using the device. But the pace and scope of the rehabilitation is incredible: “All three patients were able to stand, walk, bike, swim and control their trunk movements within days of activating the implants,” says Courtine.
“This is possible thanks to the specific stimulation programs that we have designed 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.”
While the progress that can be made in a single day is incredible, the progress made over several months is even more impressive. All three patients followed a training regimen based on the stimulation programs and were able to regain muscle mass, move more independently and participate in social activities such as having a drink while at a bar.
Also, as the technology is miniaturized, patients can perform their training exercises outdoors and not just inside a lab.
“This study further demonstrates the benefits of our approach,” says Courtine. “Now we are working with FORWARD Doctorwhich is already listed in Euronextto transform our discoveries into real treatments that can improve the lives of thousands of people around the world”, he underlines.