The electrical implant helps paralyzed patients for years to take action

By LAURAN NEERGAARD

WASHINGTON (AP) – Three people, whose legs have been paralyzed for years, can get up and take measurements with an electric implant that zaps the injured spinal cord, as well as months of intense reeducation, researchers said Monday. .

This step, reported by two teams of scientists working separately, is not a cure. Patients only walk with help – standing at a walker or with other help to keep their balance. Turn off the spinal stimulator and they can not move their legs voluntarily.

But during a physiotherapy session at the Mayo Clinic, 29-year-old Jered Chinnock made enough rounds to cover the length of a football field.

"The side of the walk is not something I leave my wheelchair behind," said Chinnock of Tomah, Wisconsin, Associated Press. But "there's the optimistic side of, maybe I'll win – where I can leave the wheelchair behind, even if it's for walking up to the fridge."

This work is part of a quest to help people with spinal cord injuries return to work, and experts say it has been tried by only a few people, but it is a promising approach. which requires more studies.

"I'm really excited about this," said Dr. Cristina Sadowsky, a rehabilitation expert at Johns Hopkins University, who was not involved in the new research. He touched "residual connections that are not used" after a spinal cord injury.

Still, "everyone who has a similar injury will not respond in the same way," warned Sadowsky, who directs spinal cord treatment at the Baltimore Kennedy Krieger Institute.

Serious spinal cord injury leaves the brain's instructions to "move" unable to reach the nerves that activate the muscles. Researchers have tried other technologies, such as wrapping patients in robotic exoskeletons or implanting muscle stimulators, to help move paralyzed limbs.

According to the new approach, the three patients are taking action on their own – intentionally moving, according to reports released Monday by Nature Medicine and the New England Journal of Medicine.

How it works? One theory: the nerve circuits below the site of the lesion are dormant, but still alive. The application of an electric current, in custom models, could awaken some of these circuits and, with careful rehabilitation to revive rusty connections, eventually allow them to receive simple commands.

"Recovery can occur if you have the right circumstances," said Susan Harkema, a professor at the University of Louisville and co-author of the New England Journal's study. The spinal cord "is learning to do things less well than before, but it can work".

"This study gives hope to people facing paralysis that functional control is possible," said Dr. Kendall Lee, a Mayo neurosurgeon who treated Chinnock and co-authored the Nature Medicine report.

Four years ago, the Harkema team made headlines when a few patients implanted with spinal stimulators – originally developed to treat pain – were able to move their toes, move their legs and get up. briefly. But they did not work.

Lee and Kristin Zhao, who runs the Mayo Food and Beverage Laboratory, decided to repeat the experiment – and the success of Chinnock surprised them.

He had been paralyzed in a snowmobile accident in 2013, with no movement or sensation below his mid back. He underwent 43 weeks of intense physical therapy and stimulator adjustments. At first, trainers positioned their knees and hips to help them stand up, swing their legs and move their weight on a treadmill.

But finally, looking in a mirror, he learned to move his legs and propel himself with a walker, although with a trainer back in case he lost his balance.

He can tell his therapists when he will start, stop or speed up, Zhao said, "It's really a thoughtful and intentional movement."