Two people with paralysis walk again with an implanted device

After Kelly Thomas's truck returned in 2014, she was told that she would probably never walk again. Now, with the help of a spinal cord implant she nicknamed "Junior," Thomas is able to walk alone.

Thomas and Jeff Marquis, who were paralyzed after a mountain bike accident, can now walk independently again after participating in a study published at the University of Louisville New England Journal of Medicine. Thomas's balance is still off and she needs a walker, but she can walk a hundred yards on the grass. She also gained muscle and lost the nerve pain in her foot that has persisted since her accident. According to a similar study from the Mayo Clinic, also published today in the journal, another anonymous person with a spinal cord injury can now independently cross the ground with the help of a doctor. ;a trainer. Medicine of nature.

In the United States, nearly 1.3 million people are paralyzed because of spinal cord injuries. The hope is that standing and walking can help increase independence, improve circulation and bone density, and improve cardiovascular health. "There is no real cure for people with this type of injury," says Susan Harkema, associate director of the Kentucky Spinal Cord Injury Research Center at the University of Louisville and senior author of the New England Journal of Medicine paper. "It does not take them back to their wounds before, but it gives them an important return of function and health, and that can dramatically improve their daily lives."

Kelly Thomas and Jeff Marquis describe their experiences by participating in the research program of the University of Louisville. Video: University of Louisville

For Thomas, when she walked unaided for the first time, "it was like watching fireworks, but from within," she said. "Something I was never supposed to do had never happened. It was awesome. There is no other sensation in the world. The device Thomas calls "Junior" is a 16-electrode system that electrically stimulates the spinal cord. With intense training and what Harkema calls "a whisper of intent" from Thomas's brain, the device helped Thomas to walk again.

The technique does not work perfectly for everyone: two other participants at the University of Louisville have not relearned to walk, although they can now stand up, hold their torso straight and move their legs. "There are still ways to make it truly functional and to allow people to move again as the primary means of mobility," says Jennifer Collinger, a professor of physical medicine and rehabilitation at the University of Pittsburgh. But even a limited ability to walk is good for your health, she says. "This is the first time anyone has demonstrated functional walking activity in a person with a complete spinal cord injury."

Thomas was 19 years old and was driving near her home in central Florida when her truck left the shoulder, she said factually. She overcorrected, the truck rolled over and hit her head on the roof, squeezing her spine. At the hospital, she remembers that people told her how unlikely it was that she could walk again. "My surgeon personally told me," I will not say zero, but maybe one, maybe two percent, "she says. "I told him," Okay, I'll be your one or two percent. "

Photo: University of Louisville

Thomas is enrolled to participate in future research at the University of Louisville. And in November 2016, she received a call asking her if she wanted to enroll in a study. Thomas was torn She had already undergone intensive physical therapy and was able to stand up at that time. But there was a problem: to participate, she had to undergo surgery to implant Junior. "I did not want to lose anything for which I had worked so hard," she says. "I had so much recovered and the surgery scared me."

Junior is the RestoreAdvanced SureScan MRI Neurostimulator manufactured by Medtronic and approved by the FDA for pain management. (The Mayo Clinic study used Medtronic's RestoreUltra SureScan MRI Neurostimulator.) Thomas controls it using a remote control that communicates through his skin with a hub in his abdomen. "I have to have a remote to start and stop, and when she's stopped, I'm completely paralyzed," she says. "Whenever possible, I can get out my legs, I can walk, I can move my toes. I can do just about anything I need to do.

It may seem a little strange to use a pain control device to restore the ability to walk. But animal research has shown that rats with spinal cord injuries can learn to train, take medicine and stimulate the spine. And paralyzed people can do recumbent footsteps, with or without spinal cord stimulation. So, this suggests that parts of the spinal cord responsible for walking should still work in these patients. "If you cut off the head of a snake, the snake will continue to move – you can not even say it's not controlled by the head," says Reggie Edgerton, professor of integrative biology and Physiology at the University of California at Los Angeles. a co-author on the Medicine of nature paper. "All this is integrated into the spinal cord."

This video shows the progress of the training of the anonymous participant in the Mayo Clinic study. Video: Zhao et al. Mayo Clinic; Medicine of nature.

According to one theory, after a spinal cord injury, these spinal networks risk losing the electrical charge and the information they receive from the brain – although some weak connections may remain. And that's where the spinal stimulator comes in: it basically loads the spinal cord so that with enough practice and practice l & # 39; intent To move, Thomas's body could relearn to walk. "Combined with all the sensory information you get by moving your legs in a steppe-shaped model, and that tiny whisper of a signal of intent that they're still falling out, everything comes together, "explains Harkema.

The key was to learn to work with the pacemaker, says Thomas. She had to concentrate to move her legs. "It's not a quick fix to paralysis. You do not turn it on and you automatically return to where you were before an injury, "she says. "You have to find how to use it, how to work again with your body."

After months of training on a treadmill and walking on the floor with coaches moving her feet, she made her first steps in February 2018. "I watched the coach and I started crying, "says Thomas. "Oh my god, everything I had been working for for three years and I had said, 'You're never going to start again,'" she says. "I turned what was impossible into possible and it was liberating."

Photo: University of Louisville

Researchers still do not know why it works so well for Thomas and Marquis, but less for others. This could be differences between study participants' injuries, training patterns, or the stimulation itself. "We still do not know. We need to do more tests, "says Harkema.

But before the team can do these larger trials, the technology needs to become more accessible. At this time, the controllers must be operated by hand and the function of the hand may be limited by spinal cord injury, depending on the location of the injury. A next step will be to activate speech stimulators. The technology exists, but applying it to a spine stimulator requires investment in the technology sector, and this is not the responsibility of researchers, says Harkema. "We have Siri, for the love of God!"

These days, Thomas is back home and lives with his parents in Central Florida. The edge that she specializes in criminal justice at the College of Central Florida. She can now walk with a walker, provided the stimulator is on. But her next goal is to improve her balance so she can give up the walker. "If I lean forward too much, I may fall," she says. "It's my next step, to figure out how to catch myself if I start to fall."