[DIGEST: Nature, BBC, IFLS, ScienceAlert]
People with spinal cord injuries may walk again someday, thanks to a new wireless brain implant. The technology bypasses the spinal cord to establish wireless communications directly between the brain and the legs. Researchers from the Swiss Federal Institute of Technology successfully used the implant to enable two paralyzed rhesus macaques to walk again. The researchers say the technology could be available to humans within the decade.
People who become paralyzed through an injury to the spinal cord rarely recover movement. Depending on where on the spinal cord the injury occurs, the person may lose feeling and movement below their waist (paraplegia) or below their neck (quadriplegia), due to severed communications from the brain, which sends electrical signals down the spinal cord, to the limbs.
In the study, researchers placed a chip in the part of the monkeys’ brains that controls movement. The chip interpreted spikes of electricity in the brain that indicate instructions to move the legs, and then sent information to a corresponding implant in the spine that controls the nerves in the legs. The process, which takes place in real time, coordinates movement by bypassing the severed spinal cord with technology.
"The link between decoding of the brain and the stimulation of the spinal cord is completely new,” said Jocelyne Bloch, a neurosurgeon from the Lausanne University Hospital. "For the first time, I can image a completely paralyzed patient being able to move their legs through this brain-spine interface."
Dr. Gregoire Courtine, one of the researchers, said the experiment is the first time that a neurotechnology has restored movement in paralyzed primates — although differences between humans and monkeys mean the technology will need to be fine-tuned. "The way we walk is different to primates. We are bipedal and this requires more sophisticated ways to stimulate the muscle.”
Even so, this and other studies are giving hope to people living with paralysis. In 2012, the Lancet published results from a study in which a quadriplegic woman achieved the ability to move a robotic arm using her brain waves. In 2014, four paraplegic men took part in a study that used electrical stimulation of the spinal cord to flex their feet, toes, ankles and knees. Although they were unable to stand or walk, even this minimal restored movement improved their muscle mass, as well as bowel and bladder function, which are impacted by spinal cord injuries. In a Chinese study published in the U.S. medical journal Surgery in 2016, researchers were able to restore spinal cord function to animals by injecting polyethylene glycol compounds into the spinal cord to stimulate the injured nerve cells to regenerate.
Despite continual small achievements in the scientific world, and optimistic news stories promising a cure for paralysis just around the corner, at this time, no such cure exists. The Christopher and Dana Reeve Foundation says that 1 in 50 people live with paralysis, and pressure is on the medical community to bring these people the means to improve their quality of life. This may change in the coming years, however, if this technology lives up to the hype. hopes. All implants and components involved in the monkey studies have been approved for human research.