We're One Step Closer to Reversing Paralysis
A new implant joins a small set of treatments offering hope to people with spinal injuries.
Jordan Fallis had been hurt before: a broken arm, broken ribs, a fractured wrist, a fractured hip—but that didn't deter him from riding. BMX was his passion, and although he always wore protective gear, injuries and brushes with death were things he accepted as part of the deal. One morning in October 2014, the then 24-year-old went to his usual spot in Peoria, Arizona, to practice the routine flips and jumps he'd done hundreds of times before. Well into the afternoon, he entered a backflip but under-rotated, hit the front wheel first, and then fell to the ground. He felt his body tingle like an electric current was passing through it. He remembers hoping he had pinched a nerve.
Fallis remained conscious as his friends strapped him onto a piece of plywood and then four-wheeled him to a helicopter that flew him to St. Joseph's Hospital in Phoenix, Arizona. A series of MRIs and x-rays revealed a fracture in his lower spinal column. Pieces of the bone had pierced his spinal cord, paralyzing him from the waist down. Several hours later, his doctors asked if he would be willing to undergo an experimental surgery that might allow him to walk again.
There wasn't time for second opinions or mulling over the details with family—the surgery had to be completed within 96 hours of the injury. Fallis decided he was willing to try his luck one more time. "It didn't bother me that no one had gotten this before," he says. "Anyone in my shoes would've done it. What do you have to lose at that point?"
Doctors cut into his spinal cord, cleared away the dead cells that had accumulated since the injury, and inserted a tiny, cylindrical capsule made almost entirely out of biodegradable fibers, which would act like a trellis where new nerve cells could hang and multiply. Though it had been tested many times before on mice, Fallis was the first human patient in the world to receive the treatment—and it was unclear how he would respond.
About 17,000 people in the US experience spinal cord injuries (SCIs) every year, due to car accidents, falls, gun shot wounds, and recreational activities such as biking. Depending on the severity of the injury and how many nerves are damaged, this can cause a host of problems, including loss of bladder and bowel function, muscle weakness in the arms, legs, or abdomen, and paralysis. For most people, it can take years of physical therapy coupled with some luck before they regain muscle movement or the ability to walk, if that happens at all.
Most patients have one option if they arrive at the hospital with a spinal injury. "We do what we've done for 75 years: put in rods and screws to stack the vertebrae, which takes pressure off the spinal cord, but the cord itself remains damaged," says Nicholas Theodore, the neurosurgeon who performed Fallis' surgery and director of the Johns Hopkins Neurosurgical Spine Center. "You still have inflammation that damages neurons, and nerve cells that are self-destructing and scarring, which prevents new cells from growing."
The implant Jordan received nine hours after his accident is called a neuro-spinal scaffold. It was created by InVivo Therapeutics, a biotechnology startup in Cambridge, Massachusetts. Researchers there hope that the new cells that grow around the trellis can spark connections between the spinal cord and the body, nudging the body to regain what it has lost, at least partially. Seven other SCI patients have received the treatment in the months since Fallis did.
InVivo isn't the only company trying to advance the treatment of SCIs with experimental therapies. Researchers at the University of California-Davis, for instance, recently enrolled their first patient in a study for a drug called VX-210. Applied topically over the spinal cord, scientists speculate that it could regenerate previously damaged axons, the part of nerve cells that transmits information. Another drug, glyburide, has been used for years to manage diabetes and, in another setting, reduce brain swelling after stroke. It's now being tested out with spinal cord injuries to reduce swelling in the wake of an injury, which in turn could keep cells in the spinal cord alive.
Stem cell treatments have become part of the picture, too. Researchers at Rush Medical Center in Chicago and the University of Southern California recently injected 10 million human embryonic stem cells into the spinal cords of paralyzed individuals, and saw improvements like increased sensation and movement in their arms and hands. All of these options, much like InVivo's scaffold, are still in the early stages of testing.
In the days after his fall, Fallis had become paralyzed from the waist down, with no sensation in his legs and no ability to control his bowels or bladder. A month later, after undergoing physical therapy four times a week, he was able to move his legs, and had regained some feeling as well. He had gone from the most severe grade of injury—what's considered AIS-A, according to a scale developed by the American Spinal Injury Association—to AIS-C. Improving two grades on the AIS scale in four weeks happens in less than five percent of patients.
In InVivo's ongoing clinical trial, five out of eight patients (including Fallis) have improved to at least an AIS B level, meaning they are starting to get feeling back, but can't yet move the paralyzed parts of their bodies. While these results sound promising, having only eight sets of data doesn't tell us enough.
"The concept is sound, as scaffolds have been used for decades in medical research and proved to be beneficial to cell regrowth in certain situations," says Michael Lane, assistant professor at Drexel University College of Medicine. "But right now, we have to be cautious and see whether or not these results can be reproduced in many, many more people."
Because it's so early and the implant's impact has yet to be studied, it's premature to give it all the credit in recovery. "It's hard to say 100 percent whether Fallis' progress was solely the work of the scaffold," Theodore says. "It could have been spontaneous, it could have been the fact that we removed all that dead tissue and cells, it could very well be the scaffold or a combination of all of those factors. I want to be careful about that."
Francis Farhadi, an associate medical director at the Ohio State University Wexner Medical Center who was not involved with the InVivo study but is a principal investigator of glyburide, expressed a similar sentiment. He adds that while Fallis' one-month recovery progress was quick, long-term improvements are not unusual. "Up to 20 percent of people who have an AIS A injury like Jordan can get better within one to six months, sometimes up to a year, and are able to regain sensation and movement," Farhadi says. "He could have simply been in that group."
Since most of the options for spinal cord treatment are still in clinical trials, there's no way of telling if the progress that's been observed in a few individuals will continue when more tests are complete. It's also possible that truly successful treatment of these injuries won't involve just one method but a combination of treatments—some to stop more damage from happening and others to promote the growth and regeneration of cells, says Farhadi.
At his one-year exam, Fallis was able to walk with the assistance of a walker and braces. In the video of the moment, a smile spreads slowly across his face, signaling a victory. "People think that taking a year to relearn to walk is a long time, but I have met people who have gone through the same injury, and after five or seven years they are still not able to walk," he says. "I still have a long way to go but I'm far ahead of a lot of people. That has to mean something is going right."
Maybe Fallis was a lucky case, or maybe the scaffold did serve as an incubator for new cell growth that accelerated his success. It will take testing on hundreds of more patients to confirm which it was. "We don't have anything like this, so the future of this technology is exciting," says Theodore. "But we have to make sure we are faithful to science before we make conclusions."
Image: Dana Kim