They couldn’t move their legs, not even feel them. Several paraplegic patients are now able to walk again thanks to an implant that electrically stimulates their spinal cord, an advance that could become widespread in the next few years.
• Read also: Tuberculosis kills more due to Covid-19
• Read also: A new, more virulent HIV variant identified in the Netherlands
• Read also: Cell death similar to AIDS
This technology has allowed three paraplegics “to stand again, to walk, cycle and swim again”, summarizes a study published Monday in the journal Nature Medicine.
These three patients, all men, were not only incapable of any movement of the legs, but they no longer had the slightest feeling there, following accidents which had damaged their spinal cord.
The spinal cord, contained by the vertebral column, extends the brain and controls many movements. These can therefore be irretrievably lost if the contact with the brain is damaged.
But, for these three patients, it was possible to change the situation. In Lausanne, a team, led by the Swiss surgeon Jocelyne Bloch and the French neuroscientist Grégoire Courtine, implanted them with about fifteen electrodes which make it possible to electrically stimulate several areas of their spinal cord.
This is not a first, but rather the culmination of ten years of work of this type with, finally, the prospect of making it a therapy that would change the lives of many paralytics.
The idea of sending an electric current to regain lost motion dates back decades and was first put into practice in 2011 when a paraplegic was able to stand upright again.
Walk a mile
In 2018, several teams, including already that of Ms. Bloch and Mr. Courtine, had succeeded in getting patients to walk again using such technology.
But we were still far from being able to envisage a concrete application. The patients concerned had needed several weeks to redo a few steps and their progress remained limited, with little benefit to their daily life.
This time, the operated patients were able to take their first steps almost immediately, even if they were taken on a treadmill in the laboratory and had nothing to do with normal walking.
“You shouldn’t imagine an immediate miracle (but) it allows you to practice your activities right away,” explained Mr. Courtine during a press conference.
After five months of rehabilitation, the progress was considerable: one of the patients, for example, was able to walk almost a kilometer without interruption.
To achieve such breakthroughs, the researchers improved the technology used compared to previous experiments.
These were based on pre-existing electrical stimulation tools. However, these devices were designed for a different purpose: to reduce pain and not to stimulate movement, a much more complex objective, especially since each human being has a spinal cord with very variable characteristics.
A few hours a day
This time, “the electrodes are longer and larger than those used before, which allows access to more muscles”, detailed Jocelyne Bloch.
Another important advance, thanks to software using artificial intelligence, the electrical impulses are much more precise: they correspond better to each movement, instead of consisting of an indiscriminate current flow.
When will these advances be able to benefit the greatest number? “With a bit of luck, within a few years,” said Ms. Bloch.
The technology is to undergo much larger clinical trials under the aegis of a Dutch startup, Onward. This company aims to make it easily usable using a smartphone, for example to control its triggering.
Because this is one of the limits to take into account: as soon as it is turned off, the electrical stimulation has almost no lasting effect. And it is inconceivable to maintain it permanently, which would exhaust the patient’s organism.
But finding a little movement every day is already a lot, as evidenced by one of the patients, Michel Roccati, in whom these electrodes were implanted in 2020, three years after a serious motorcycle accident.
“I use it every day for a few hours: at work, at home, for a lot of things,” he said. “Now it’s part of my daily life.”