Particularly impressive work, even in the current context where regenerative medicine is progressing very rapidly.
In impressive work published in the prestigious journal Nature Medicine, Swiss researchers from the Ecole Polytechnique Fédérale de Lausanne (EPFL) presented the progress of their work on the healing of nerve trauma; they succeeded in restoring partial use of their legs to three paraplegics thanks to a nerve implant.
In practice, the result is comparable to that of other recent works which have also succeeded in restoring the partial use of their limbs to paralyzed people. But the approach, on the other hand, is quite different. Here, point of brain-machine interface, stem cells or network of “dancer” nanofibers; instead, the system relies on an implant placed at the level of the spine.
In the context of paraplegia of traumatic origin, there is often a partial or even total rupture of the spinal cord – or rather spinal cord, according to the new nomenclature. This is obviously a big problem since it is the interface that allows our brain to deliver its instructions to the four corners of the body through all the ramifications of the nervous system. When the spinal cord is severed, all the structures downstream are therefore unable to communicate and therefore to function. This channel of communication must therefore be restored.
Impressive preliminary results
To achieve this, Grégoire Courtine’s team began by developing a predictive model of the functioning of the spinal cord of an average human using a system based on artificial intelligence. This model then served as a reference for the surgeons who had to implant the numerous electrodes necessary for the transit of the signal, one by one, directly in contact with this delicate structure. They then only had to calibrate each implant so that the signal was adapted to the patient.
After the operation, the results were quite impressive. In less than a day, the three patients had all recovered some degree of movement in the legs, whereas they were completely deprived of it until then. They were even able to take a few steps on a treadmill. “The first steps were amazing, a dream come true”, explains one of the patients in a press release.
After a short period of training, the participants were even able to perform more complex movements such as balancing, pedaling, or even swimming. And after several months of rehabilitation, one of the patients is even able to walk a kilometer without interruption! Extremely impressive, knowing that it is indeed a former total paraplegic.
Particularly solid work
Another remarkable fact: the publication seems to have been hailed almost unanimously by specialists in the discipline. This is a rare enough fact to be underlined, because in this is a field of research where we regularly see heaps of work appearing revolutionary, but too far removed from concrete reality. Here, no pixie powder, but solid work, and documented in an extremely solid way.
Reggie Edgerton, an exercise physiologist at the University of California interviewed by Nature, said to himself “impressed with the level of detaill” of the publication. Above all, he welcomes the global aspect of this approach. Indeed, the researchers didn’t just graft a sort of multi-switch onto the spinal cord to control the leg muscles; it is all about restoring the integrity of the original system, including the link between the trunk and the lower body. “We don’t just walk with our legs!”, insists Edgerton.
The other big advantage of this approach is that it allows the nervous mechanisms involved to be explored with great precision. The feedback from the three patients will allow the researchers to “better understand the dynamics of spinal cord signals”, which could then make it possible to tackle other forms of loss of control, for example at the level of the bladder or erectile function. Eventually, they even hope to be able to tackle the most serious forms of paralysis, such as quadriplegia.
Grégoir Courtine’s team has just received approval from the American administration to launch a clinical trial in the United States, in order to test the device on more patients. They hope to be able to treat people who have recently become paraplegic; this would minimize the degradation of neural pathways, which could make the treatment even more effective. It will therefore be necessary to follow the progress of this work with particular attention, because it could change the daily lives of many patients within just a few years.
The text of the study is available here.