Wireless brain implant lets paralyzed monkeys walk again

In a breakthrough that could one day help people with paraplegia walk again, researchers from the Swiss Federal Institute of Technology in Lausanne (EPFL) have helped paralyzed monkeys regain the use of their legs following a spinal cord injury using a new wireless device.

According to CNN and the New York Times, the EPFL scientists restored movement in the legs of two paralyzed rhesus macaques within two weeks by installing implants to establish a wireless connection from their brain to the part of the spine located directly below the damaged area.

The implants established a brain-spine interface that transmitted nerve signals from the brain to the spine, communicating with one another through computers and allowing the signals to bypass the injured part of the spine, the researchers explained. By re-establishing the broken connection, the system enabled one of the two monkeys to regain mobility in just six days.

“This is the first time that neurotechnology restores locomotion in primates, but there are many challenges ahead and it may take several years before all the components of this intervention can be tested in people,” neuroscientist Grégoire Courtine, lead researcher and corresponding author of a paper published Wednesday in the journal Nature, explained in a statement.

Goal is to adapt the technology for use in humans within 10 years

The interface works by decoding brain activity associated with the movements required to walk, then relaying this information wirelessly to the spinal cord below the injury. It does this by using electrodes that simulate the neural pathways needed to activate leg muscles, the authors said.

By reconnecting the previously broken neural pathway, the signals can arrive at the lower part of the spine, resulting in nerve stimulation that allows specific muscles in the legs of both macaques to be activated as needed when commands from the brain are received, CNN said. The important thing, Courtine said, is to “stimulate to induce the desired movement of the animal.”

When used in a monkey that suffered a partial lesion of its spinal cord, the EPFL team reported that the device allowed the primate to regain control of its paralyzed leg almost as soon as it was activated. They noted that it should also work for more serious spinal cord injuries if used along with pharmacological agents, and they are hopeful that it will eventually help paralyzed humans to walk again. However, Courtine cautioned, that is still a long way off.

“The idea is to go step-by-step,” he told CNN, adding in a separate comments to the Times that he and his colleagues hoped that the system could be adapted for use in people within “the next 10 years.” The goal, Courtine noted, is to “improve recovery and quality of life” but he stressed that “people are not going to walk in the streets with a brain-spine interface,” any time soon.


Image credit: Alain Herzog/EPFL