Paralyzed man can walk by activating spinal implants with his mind

A Dutch man who was left paralyzed after breaking his neck can now walk on crutches after receiving implants that allow his brain to send signals to his spine via a computer in a backpack.

Gert-Jan Oskam, 40, can now stand up from a sitting position, climb stairs and walk outside on uneven ground. “The stimulation will kick in as soon as it thinks of [taking] one step,” he says.

Oskam also found that even when the device is turned off, he can walk short distances with a rolling walker. Grégoire Courtine of the Swiss Federal Institute of Technology (EPFL) in Geneva and his colleagues, who developed the technology, think this may be because repeated exercise has stimulated new growth of nerve cells in the spinal column.

Brain implants are contained within two 5-centimeter discs that rest on the surface of the brain, replacing two circles of bone taken from the skull. They communicate wirelessly with a helmet-like receiver, which sends signals to the backpack’s computer. The computer then sends signals to stimulators placed in Oskam’s spinal cord, which trigger movements in his leg muscles.

The system is an update to the first version, which Oskam received five years ago, which involved only the spinal electrodes. With this version, Oskam activated each step by making a small heel movement, which he was able to do because the accident had not completely severed his spinal cord. Heel movements were detected by lightweight motion sensors, and this caused the spinal implants to trigger semi-automatic stepping movements coordinated by networks of neurons in the lower part of the spinal cord.

The resulting steps allowed Oskam to walk on level ground using a wheeled walker. “This was more like a robotic stepping motion,” says Courtine.

In 2021, Oskam got the brain implant upgrade. Within minutes of surgery, he was able to walk and this led to more natural movements. “He can adjust when the stimulation comes on and how much. He makes the movement very fluid,” says Guillaume Charvet from Grenoble Alpes University in France, another member of the team.

“The stimulation used to control me, and now I control the stimulation with my thoughts,” says Oskam.

The brain-controlled system also leads to a wider range of movements of the hips, knees and ankles, says Henri Lorach, a member of the EPFL team. “He can access multiple functions.”

So far, nine people in total have received just the spinal implants, controlling their movement by making small residual movements of their legs, as Oskam did, or by pressing buttons on the walker. Some may now have the update.

The team also has approval to try using the same approach to restore arm movements in people who are paralyzed from the neck down.

“This is beautiful work,” says Zubair Ahmed of the University of Birmingham, UK. “The good thing about this is that they are linking a lot of technologies together.”

However, the system is still in the early stages of development and would be too expensive for other people with spinal cord injuries to use widely, he says.