A paralyzed man has regained the ability to walk smoothly using only his thoughts for the first time, researchers said Wednesday, thanks to two implants that restore communication between the brain and spinal cord.
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Patient Gert-Jan, who did not want to give her last name, said the collapse gave her “a freedom I didn’t have” before.
The 40-year-old Dutchman has been paralyzed in his legs for more than a decade after suffering a spinal cord injury during a bicycle accident.
But with a new system he can now walk “naturally”, ride on rough terrain and even climb stairs, according to a study published in the journal Nature.
The development is the result of more than a decade of work by a group of researchers in France and Switzerland.
Last year the team showed that a spinal cord implant — which sends electrical pulses to stimulate movement in leg muscles — allowed three paralyzed patients to walk again. But they have to press a button to move their legs each time.
Gert-Jan, who also has a spinal implant, said it made it difficult to get into the rhythm of taking a “natural step”.
‘Digital bridge’
The latest research combines the spinal implant with a new technology called a brain-computer interface, which is implanted over the part of the brain that controls leg movement.
The interface uses algorithms based on artificial intelligence techniques to decode brain records in real time, the researchers said.
This allows the interface, designed by researchers at the Atomic Energy Commission (CEA) in France, to determine how the patient wants to move their legs at any time.
Data is transmitted to the spinal cord implant through a portable device that fits on a walker or small backpack, allowing patients to get around without help from others.
The two implants build what the researchers call a “digital bridge” to bridge the disconnect between the spinal cord and brain that was created during Gert-Jan’s accident.
“Now I can just do what I want – when I decide to make a move the stimulation starts as soon as I think about it,” says Gert-Jan.
After undergoing invasive surgery twice to implant both devices, it was “a long journey to get here,” he said at a press conference in the Swiss city of Lausanne.
But among other changes, he was once again able to stand in a bar with friends while drinking beer. “This simple pleasure represents a significant turning point in my life,” he said in a statement.
‘very different’
Gregoire Courtine, a neuroscientist at Ecole Polytechnique Federale de Lausanne in Switzerland and a co-author of the study, said it was “very different” from what had been done before.
“Previous patients walked with great effort – now one has to think about walking to take a step,” he said at a press conference in the Swiss city of Lausanne.
There is another positive sign: after six months of training, Gert-Jan regained some sensory perception and motor skills that he lost in the accident. He was still able to walk with crutches when the “digital bridge” was turned off.
Guillaume Charvet, a researcher at CEA in France, told AFP that it suggests “that the establishment of a link between the brain and spinal cord can promote a reorganization of neuronal networks” in the area of the injury.
So when will this technology be available to paraplegics around the world? Charvet warned that it would take “many more years of research” to get to that point.
But the team is already preparing a trial to study whether this technology can restore the function of arms and hands. They also hope to use it for other problems such as paralysis caused by stroke.
(AFP)
