Gert-Jan Oskam, who suffered a spinal cord injury in a bicycle accident eleven years ago, has become the first paraplegic person to regain the ability to get up and walk with control of his legs naturally. His recovery has been possible by reconnecting the brain and spinal cord with wireless technology developed by the team of Grégoire Courtine and Jocelyne Bloch in Lausanne (Switzerland), world pioneers in this field of research.
"Our goal is to make this technology available worldwide to all patients who need it," said Grégoire Courtine, from the Federal Polytechnic School of Lausanne (EPFL) and the Lausanne University Hospital, yesterday at a press conference. The researchers have founded the company Onward Medical with funding from the European Commission to develop a commercial version of the technology, which is currently experimental.
Courtine cautioned that Gert-Jan Oskam is the only person who has received the treatment so far and that studies with more participants will be needed in the coming years before the technology can be applied on a large scale.
“The sensation is very similar to the normal sensation of walking. I feel like I'm applying force to the ground, which allows me to take a good step. I am practicing the quality of my steps," Oskam, who has been collaborating as a volunteer in Courtine and Bloch's investigations since 2017, told the press conference.
He regained the ability to start walking in an earlier trial in which electrodes were implanted in his spinal cord to control his leg muscles. Although it was a significant improvement, “the stimulation was not natural,” Oskam explained. “Before the stimulation controlled me; now I control the stimulation.”
His ability to walk is far from what he had before suffering the spinal cord injury. He walks a hundred or two hundred meters a day, stands without supporting himself with his hands for two or three minutes, and can climb stairs. But he perceives the movement as fluid and natural. “Before the stimulation was activated by a computer; each step was a bit stressful because I had to time it with the rhythm [of the neurostimulator]; now I can do what I want, ”he explained.
The treatment Oskam has received consists of two electrode implants, the researchers report in the journal Nature, where they are presenting the progress today. One of the implants is placed in the head to record signals from the brain that encode the will to walk. The other is placed on the spinal cord, below the point of spinal cord injury, to transmit signals to the legs. “We captured the brain's natural control signal and reconnected two regions of the nervous system that had been disconnected,” explained Grégoire Courtine, who has devoted twenty years to this line of research.
The signals registered in the brain are processed with algorithms based on artificial intelligence to interpret the intention to walk in real time. The signal is transmitted to a neurostimulator that activates electrodes in the spinal cord. These electrodes, in turn, activate neurons that reach the appropriate muscle groups to perform the desired movement. Thus, what Courtine calls “a wireless digital bridge” between the brain and the spinal cord is established.
"When I met Grégoire eleven years ago and he explained this idea to me, it seemed like science fiction," neurosurgeon Jocelyne Bloch, who is now co-director of the project, acknowledged at the press conference.
Once the electrodes are implanted, a rehabilitation treatment under medical supervision is necessary so that the patient learns to master the implants and recovers voluntary control of walking. In Oskam's case, his evolution was so good that the medical team suggested that he use this experimental technology in his daily life, outside the hospital.
To the researchers' surprise, their abilities improved not only when the electrodes were on but also when they were turned off. He can now lift one leg or walk on crutches without the need for neurostimulation.
According to the researchers, the neurostimulation led to a reorganization of their neural circuits. Therefore, the neurological improvement that can be expected in other patients in the future will depend on the severity of their spinal cord injury. In Oskam's case, the injury was serious, but not complete.
“We have understood how to dialogue with the spinal cord,” Courtine declared. “Paralysis is the tip of the iceberg for spinal cord function. Now we can start working on bladder or blood pressure control.”
The Lausanne team also plans to test the technique on people with quadriplegia to regain control of their arms and hands, as well as on patients who have been disabled after suffering a stroke.
"Although these developments will require time and resources, we do not anticipate that there will be technical obstacles," conclude the researchers in Nature. "The concept of a digital bridge between the brain and spinal cord heralds a new era in the treatment of motor deficits due to neurological disorders."