Twelve years ago, a bicycle accident damaged the spinal cord in his neck, leaving Gert Jan Oskam, now 40, paralyzed in his legs and partially paralyzed in his arms. Recently, however, Oskamm has been able to stand and walk thanks to a device that creates a “digital bridge” between his brain and the nerves beneath the injury.
Oscam says the implant changed his life. “Last week he needed to paint and no one was there to help him, so he brought a walker and paint and stood up and painted it himself,” he says.
The device, called a cerebrospinal interface, builds on previous work by neuroscientist Gregoire Courtin and colleagues at the Swiss Federal Institute of Technology Lausanne. In 2018, researchers demonstrated that a technique that stimulates the lower spine with electrical pulses, combined with intense training, can help people with spinal cord injuries walk again.
Oskamu was also a participant in the trial, but after three years his improvement plateaued. The new system takes advantage of Oscam’s existing spinal implants and combines them with two disc-shaped implants inserted into the skull so that two 64-electrode grids hit the membrane that covers the brain.
When Oscam thinks about walking, the skull implant detects electrical activity in the outer layer of the brain, the cortex. This signal is transmitted by radio, decoded by a computer that Oscam wears in his backpack, and the information is sent to a spinal pulse generator.
Previous devices were “like pre-programmed stimuli” that generated stepping movements for the robot, Cotin says. “Now it’s completely different. Gert Yang has full control over the stimulation parameters, so he can stop, walk, climb stairs.”
“Before, my stimuli controlled me, but now my thoughts control my stimuli,” says Oscam. “When you decide to take a step, the moment you think of it, the simulation starts.”
Strengthening rehabilitation
After about 40 rehabilitation sessions using a brain-spine interface, Oskamu regained the ability to move his legs and feet on his own. Voluntary movements of this kind were not possible with spinal stimulation alone, suggesting that training sessions with the new device encouraged further recovery of neurons that had not been completely severed at the time of injury. With crutches, Oskam can walk short distances without a device.
Bruce Harland, a neuroscientist at the University of Auckland in New Zealand, says continued improvement in spinal cord function is good news for people with spinal cord injuries. Different ways healing can occur. “
“This is certainly a big leap forward” towards improving function in people with spinal cord injuries, says neuroscientist Anna Leonard of the University of Adelaide in Australia. And there is still room for other interventions, such as stem cells, to further improve outcomes, she says. She added that the brain-spine interface restores ambulation, but other functions such as bladder and bowel control are not covered by the device. “So there is certainly still room for research in other areas that could help drive improvements in outcomes in these other types of areas,” she says.
A less invasive device would be ideal, says Antonio Laut, a biomedical engineer at Western Sydney University in Australia. His one of Oscam’s skull implants was removed after about five months due to an infection. Nevertheless, Jocelyn Block, a neurosurgeon at the Swiss Federal Institute of Technology who implanted the device, says the risks are small compared to the benefits. “There’s always some risk of infection or bleeding, but they’re so small that it’s worth the risk,” she says.
Courteen’s team is now recruiting three people to see if a similar device can restore arm motion.
This article is reprinted with permission and was first published May 24, 2023.
