A previously paralysed man has been able to walk again – just by thinking about it – thanks to a new device that connects his brain and his spinal cord, bypassing an injury he suffered 12 years ago.
A cycling accident in 2011 left Gert-Jan Oskam, 40, with paralysed legs and partially paralysed arms, after his spinal cord was damaged in his neck.
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But today he is back on his feet, walking with the use of crutches thanks to a “digital bridge” between his brain and the nerves below his injury.
“Within five to 10 minutes I could control my hips, like the brain implant picked up what I was doing with my hips so that was the best outcome I think 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 what I want. When I decide to make a step the stimulation will kick in as soon as I think about it,” Oskam said. “This simple pleasure represents a significant change in my life.”
Thinking about walking
Oskam took part in a trial in 2018 that showed, with intensive training, technology to stimulate the spine with electrical impulses could help people with spinal cord injuries to walk again, although, after three years, his improvements had plateaued.
His original spinal implant has been paired with two disc-shaped implants inserted into his skull so that two 64-electrode grids rest against the membrane covering the brain.
Now when Oskam thinks about walking, the skull implants detect electrical activity in the cortex, the outer layer of the brain.
“To walk, the brain must send a command to the region of the spinal cord responsible for the control of movements. When it’s a spinal cord injury this communication is interrupted,” said Professor Gregoire Courtine, a neuroscientist at EPFL, the Swiss Federal Institute of Technology in Lausanne.
“Our idea was to re-establish this communication with a digital bridge, an electronic communication between the brain and the region of the spinal cord that is still intact and can control the leg movement,” Courtine said.
This signal is wirelessly transmitted and decoded by a computer that Oskam wears in a backpack, which then transmits the information to the spinal pulse generator.
“So when everything is installed, the patient has first to learn how to work with his brain signals and we also have to learn how to correlate these signals to the spinal cord stimulation. But this is pretty short. In a few sessions, everything is linked and the patient starts training,” said Professor Jocelyne Bloch, a neurosurgeon at EPFL.
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 journal Nature – shows a type of voluntary movement not possible after spinal stimulation alone, and suggests the training sessions with the new device prompted further recovery in nerve cells that were not completely severed during Oskam’s injury.
“What we observed along the duration of this training is a digital repair of the spinal cord,” Courtine said.
“Not only he could leverage the digital bridge in order to control his paralysed muscle, but also show a recovery of neurological function he had lost for many years, suggesting that this digital bridge also promoted the growth of new nerve connections.”
He can now even walk short distances without the device if he uses crutches.
Courtine’s team is currently recruiting three people to see whether a similar device can restore arm movements.