A 30-year-old Italian man whose spinal cord was severed in a motorcycle accident is doing something unexpected: walking. Michel Rocatti is able to do so thanks to an implanted device called a spinal cord stimulator that sends electrical signals to his legs, reports NBC News. As the BBC describes it, this "is the first time someone who has had a complete cut to their spinal cord has been able to walk freely." Swiss researchers caution that they are a long way away from translating this into a common treatment for those with spinal injuries, but the results reported in Nature Medicine are being hailed as an important milestone. (This video via the National News provides a sense of Rocatti's progress.)
The Guardian lays out the procedure, developed by neuroscientist Grégoire Courtine and neurosurgeon Jocelyne Bloch: The device makes use of a "soft, flexible electrode that is laid on top of the spinal cord nerves, underneath the vertebrae." The electrode sends pulses to nerves on the spinal cord that control muscles in test subjects' legs and torso. "The pulses, in turn, are controlled by software on a tablet that issues instructions for a certain action, such as standing, walking, cycling, or kicking the legs for swimming."
Rocatti, who was paralyzed in 2017, received his implant two years later. Two other men with similar spinal injuries followed, and all three were able to stand right away, per the study. However, it took three to four months before they could consistently move with their walkers. "It was not perfect at the beginning, but they could train very early to have a more fluid gait," says Bloch. The BBC notes those with the implants don't rely on it to walk "in their everyday lives" due to how complicated it is, but they use it to practice walking, rebuild muscle, and have some independent movement. Researchers plan to continue experimenting and perfecting with a larger group of test subjects, and they hope to try the device on subjects with more recent injuries than the first three men. (Read more medical breakthrough stories.)