His face flushed from the effort, Jered Chinnock straightened his back after a therapist helped position his feet on the floor of a Mayo Clinic hospital lab. He paused, concentrating, before he gently loosened his grip on the metal railing at his side.
“Nice control!” a physical therapist encouraged him as he recently stood perfectly still, everyone in the room watching.
It was a simple act, but for Chinnock and so many others, it was confirming a medical breakthrough:
He was standing. Unsupported. Four years after he was paralyzed.
Chinnock is one of a handful of patients in the country who, through the collaborative work of pioneering researchers, have had a small electrical stimulator implanted on their spine.
So far, the 28-year-old from Tomah, Wis., injured in a snowmobile accident in February 2013, has been able to consciously move his legs in step-like motions — both while lying on his side and while partly suspended in a harness — as well as support his own weight to stand.
“It’s just kind of in awe,” he said, describing his feelings the first time he regained slight movement shortly after getting the stimulator in August. It was a “pinch me, see-if-this-is-real kind of thing,” he said.
It was a big moment for the research team surrounding him, too.
Working with a team from the University of California, Los Angeles, researchers at Mayo set out to replicate the results of an experimental study involving four paraplegic patients who had stimulators implanted at the University of Louisville in Kentucky, starting in 2009, also with the UCLA team and others.
Louisville patients were able to flex their ankles, knees and hips when their stimulators were active, their movements enhanced with physical therapy. Some saw other improved functions, too, such as blood pressure and body temperature regulation, sexual function and bladder control.
Initial results at Mayo, published Monday in the medical journal Mayo Clinic Proceedings, were even more encouraging, bringing Chinnock a surprising amount of movement within days of using the stimulator.
Chinnock barely remembers his life-changing accident. He was thrown from his snowmobile on a lake near Hayward, Wis., and was hit by another snowmobile zooming behind him. He remembers lying curled up on the snow, struggling to breathe while explaining their location to a buddy calling 911.
He was lucky to be alive, but he had broken ribs, a punctured lung and a “complete spinal cord injury” at the sixth thoracic vertebra. He could not move or feel anything below the middle of his torso.
He underwent spinal fusion surgery — typical for spinal cord patients — and was hospitalized for months. He worked hard to strengthen his upper body and eventually returned to his passions of snowmobiling and hunting, using a bow to try to bag deer from his wheelchair eight months after the accident. He was determined to keep living a life of outdoor adventure, even sky diving tandem two years after his accident.
“It came down to … proving people wrong that I couldn’t do it,” he said.
When his doctor suggested he could be a candidate for the study at Mayo, he didn’t balk.
Chinnock’s treatment started with physical therapy. For 22 weeks before the surgery, he worked out in a lab at St. Marys Hospital three times a week, the research team measuring and documenting every exercise as they moved his paralyzed muscles for him. After some testing, researchers characterized Chinnock’s injury as “discomplete,” suggesting dormant connections may remain across his injury.
Surgeons then implanted the stimulator on his spine, the device adjustable with a remote control.
After a three-week surgical recovery period, Chinnock was back in physical therapy.
Within two weeks, with the stimulator active, he was able to accomplish four tasks that had taken previous patients weeks to months: He regained some leg movement during his first therapy session. He stood during the second. He made step-like movements while lying on his side during the fifth session and similar movements while upright with some of his body weight supported in a harness during the eighth session.
“We’ve actually gone beyond our initial hopes,” said principal investigator Dr. Kendall Lee, a neurosurgeon and director of Mayo Clinic’s Neural Engineering Laboratory. Mayo’s replication and advancement is a “major breakthrough,” he said.
While the ultimate goal is for patients to recover as much movement and function as possible, researchers said, even the initial results are beneficial. Standing will help paralyzed patients avoid pressure ulcers, for instance, which sometimes cause infections and require surgeries to fix.
“People with spinal cord injury are interested in more than just walking,” said Kristin Zhao, co-principal investigator and director of Mayo Clinic’s Assistive and Restorative Technology Laboratory. “We have an interest in recovering any function that’s important to them.”
Hope in technology
The stimulator experiment was pioneered in part by UCLA Prof. Reggie Edgerton, who four decades ago found with another scientist that, for some routine movements, the spinal cords of animals knew what to do without the brain telling them.
Edgerton eventually got lab rats with broken spinal cords to walk with electrical stimulation.
Funding and other roadblocks thwarted work on paralyzed humans, however. Finally, in 2009, he and collaborator Susan Harkema launched the Louisville study.
The work continued there and elsewhere, with grants coming from nonprofits and government agencies through the years.
Edgerton’s team also has succeeded in using stimulators over the skin. He said researchers are focusing on improving technology to make stimulators more sophisticated.
“The explanation for complete paralysis may not be what we had generally assumed. It appears there are some types of connections that remain” in the spine in most patients, Edgerton said. “We don’t have to rebuild them necessarily, just reactivate them to a point.”
Other facilities have been working on epidural stimulation, too.
In Minnesota, the Hennepin County Medical Center, the Minneapolis Veterans Medical Center and University of Minnesota are working with a Toronto group toward similar goals, said Dr. Uzma Samadani of HCMC. They have a list of patients and hope to implant stimulators in some of them soon, starting with one as soon as May, she said.
The Mayo team plans to continue its study, though enrollment for it has closed. Funding has come from nonprofits and the clinic itself.
Money to cover patient expenses for two people is being provided by the Jack Jablonski BEL13VE in Miracles Foundation, named for the Twin Cities high school hockey player paralyzed in a game in 2011 (the 13 in the name was his jersey number).
Jablonski, a junior at the University of Southern California, said the foundation is eager to be part of the research.
He is continuing therapy to keep his paralyzed muscles conditioned in the hopes that someday he will benefit from medical advancements, too.
“We want it now,” he said, “but we also understand that it’s got to be the right thing.”