Four men paralyzed after bad spinal cord injuries can all move their legs again, thanks to an electrical stimulator.
Astonished researchers say they’d hoped for some result, but nothing like what they got. They think the stimulator is retraining the mens’ nerves to work with the brain again, despite the terrible damage.
“This is wonderful news. Spinal cord injury need no longer be a lifelong sentence of paralysis,” said Dr. Roderic Pettigrew, director of the National Institute of Biomedical Imaging and Bioengineering, one of the National Institutes of Health. “It is just downright marvelous.”
Rob Summers, now 28, was the first patient implanted and his case made international headlines in 2011 when he was first able to stand using the stimulator. Summers now exercises for three hours a day and says his life has been transformed.
“It has changed my life on a day-to-day basis,” said Summers, who was paralyzed from the chest down after a hit-and-run driver plowed into him as he stood in his own driveway. “It’s given me the ability to travel alone and come and go as I please.”
Summers says he does an hour of abdominal exercises daily, reversing the gradual wasting of muscles that normally comes with paralysis.
“I can now feel soft touch, hard touch. I can feel pinpricks,” Summers, who lives in Portland, Ore., told NBC News. “I can feel the wind on my legs.”
None of the four men can walk again, but researchers believe the stimulator is retraining the damaged nerves in their spinal columns to communicate once again with the brain. They’re not sure why — it may be some connection remained after their injuries or it is slightly possible the nerves are re-growing.
“We have uncovered a fundamentally new intervention strategy that can dramatically affect recovery of voluntary movement in individuals with complete paralysis even years after injury,” the researchers, led by Dr. Susan Harkema of the Frazier Rehabilitation Institute and the University of Louisville, write in their report, published in the journal Brain on Tuesday.
Because all four men tested have regained movement, including two who were completely paralyzed, it’s likely that many people who believed they were permanently paralyzed may be able to move again, says Reggie Edgerton, distinguished professor of integrative biology and physiology at the University of California, Los Angeles, who developed the approach.
“It tells us that the information from the brain is getting to the right place in the spinal cord, so that the person can control, with fairly impressive accuracy, the nature of the movement,” said Edgerton. “We don’t have to necessarily rely on regrowth of nerves in order to regain function. The fact that we’ve observed this in all four patients suggests that this is actually a common phenomenon in those with complete paralysis.”
The stimulator was originally developed by Medtronic to treat chronic pain. It's a pacemaker-sized device implanted under the skin of the abdomen, connecting to electrodes placed near the spinal cord. When turned on, it delivers a low pulse of electricity.
For patients with chronic pain, the electricity interrupts the pain signal before it can reach the brain. The researchers adapted it to try on patients with paralysis.
“The next generation will be more precisely controlled and noninvasive,” says NIBIB’s Pettigrew, whose institute helped pay for the research, along with the Christopher & Dana Reeve Foundation.
Pettigrew says the results are no flash breakthough. They are based on decades of work. He says researchers are already working with a fresh batch of volunteers and will report new findings soon.
“It is why we come to work every day,” Pettigrew said.
The next step is to try and make the approach work without having to implant electrodes, Pettigrew said. The hope would be for an external device, with electrodes simply stuck onto the skin to stimulate the nerves.
“The implications of this study for the entire field are quite profound and we can now envision a day where epidural stimulation might be part of a cocktail of therapies used to treat paralysis,” said Susan Howley, executive vice president for research at the Christopher & Dana Reeve Foundation.
The accident cost Summers a promising possible career in baseball. He’d been a top pitcher for Oregon State University and he was struck a month after his team won the college world series.
But he’s happy now that going out to dinner is no longer an ordeal that required hours of preparation. He’s strong enough now to hop into his wheelchair and just go.
“Not only has this benefited me with the confidence to go out and do what I want to do … I can continue to live my life as I choose and not be restricted or limited,” Summers said. His doctors say he has regained continence, sexual function and even the lost ability to sweat.
“I truly believe this is the greatest thing out there,” Summers said.
Summers says he can feel the device working. “The best way to describe it is like a strong tingling sensation,” he says, almost like a limb feels after it’s “fallen asleep." “It almost feels like pins and needles.”
The three other men whose cases are described in the report are all in their 20s and 30s now and, like Summers, had been paralyzed for years before trying the device.
Kent Stephenson of Mount Pleasant, Texas, was 21 when he was paralyzed in a motocross accident in 2009. He cannot move his leg without the stimulator, but with it on can pull his leg up to his chest, straighten it, and slowly lower it again.
Andrew Meas of Louisville was injured when his motorcycle and a car collided in 2007, while Dustin Shillcox of Green River, Wyo. was 26 when a company van he was driving blew out a tire and wrecked. Stephenson and Meas both have resumed outdoor activities such as snow machining and fishing.
Each has a little different level of function with the device. “I have mentored all the other guys using it,” Summers says. “We have been like a brotherhood bonding on this.”