Paralysed man walks with device that connects brain, spinal cord
A paralyzed man can walk smoothly for the first time using only his thoughts.
A previously paralyzed man can walk again – just by thinking about it – thanks to a new device that connects his brain and spinal cord, bypassing an injury he suffered 12 years ago.
In a bicycle accident in 2011, 40-year-old Gert-Jan Oskam suffered paralyzed legs and partially paralyzed arms after his spinal cord was damaged in his neck.
But today he’s back on his feet and walks with crutches thanks to a “digital bridge” between his brain and the nerves below his injury.
“Within five to 10 minutes I had my hips under control, like the brain implant picked up what I was doing with my hips, so I think that was the best outcome for everyone,” Oskam said in a statement.
When he thinks about walking, electrodes on his brain relay the message to electrodes on his spinal cord, stimulating the spine.
“Now I can just do whatever I want. If I decide to take a step, the stimulation will kick in as soon as I remember,” Oskam said. “This simple pleasure represents a major change in my life.”
Thinking about walking
Oskam took part in a 2018 trial that showed technology to stimulate the spine with electrical impulses, with intense exercise, could help people with spinal cord injuries walk again, though his improvements had leveled off after three years.
His original spinal cord implant is combined with two disc-shaped implants inserted into his skull so that two 64-electrode grids rest against the membrane that covers the brain.
Now when Oskam thinks about walking, the skull implants detect electrical activity in the cortex, the outermost layer of the brain.
“To walk, the brain has to send a command to the area of the spinal cord responsible for controlling movement. In a spinal cord injury, this communication is interrupted,” says Professor Gregoire Courtine, neuroscientist at EPFL, the Swiss Federal Institute of Technology in Lausanne.
“Our idea was to restore this communication with a digital bridge, an electronic communication between the brain and the area of the spinal cord that is still intact and can control leg movement,” Courtine said.
This signal is transmitted wirelessly and decoded by a computer that Oskam carries in a backpack, which then relays the information to the spinal pulse generator.
“So once everything is set up, the patient first has to learn to work with their brain signals and we also have to learn how to correlate these signals with the stimulation of the spinal cord. But this is quite short. In a few sessions everything is connected and the patient starts training,” says Professor Jocelyne Bloch, neurosurgeon at EPFL.
‘digital repair’
After about 40 rehabilitation sessions using the brain-spine interface, Oskam regained the ability to voluntarily move his legs and feet.
The team says the study – published on Wednesday in the magazine Nature — shows a type of voluntary movement not possible after spinal stimulation alone, suggesting that the training sessions with the new device led to further recovery of nerve cells that were not completely severed during Oskam’s injury.
“What we observed over the duration of this training is a digital repair of the spinal cord,” Courtine said.
“Not only was he able to use the digital bridge to control his paralyzed muscle, but he also showed a recovery of neurological function he had lost for years, suggesting that this digital bridge also promoted the growth of new nerve connections.”
He can now even walk short distances without the device when using crutches.
Courtine’s team is currently recruiting three people to see if a similar device can restore arm movement.