Paraplegic Man Regains Voluntary Movement With Implanted Device, Rehab
By Daniel J. DeNoon
WebMD Health News
Reviewed by Laura J. Martin, MD
May 19, 2011 - Rob Summers can't walk -- yet. But he can do something no other person paralyzed with a devastating spinal cord injury ever has done: He can stand up from his wheelchair when he wants to.
"Being able to stand for first time was both emotional and exciting. After years of seeing no gains or recovered function, I was able to see my hard work pay off. It was as rewarding as anything I have ever done in my life," Summers said at a news teleconference.
He does it with the help of a pacemaker-like device that sends a gentle electric current through 16 electrodes implanted in his spine. The device doesn't make his muscles move -- he does. This "epidural stimulation" excites the neurons in his spine, allowing them to receive and react to sensory information from his legs.
These results are being hailed as "unprecedented in spinal cord injury medicine," a "breakthrough," and as "going to make a major impact" by spine-injury experts not directly linked to the study by Susan Harkema, PhD, of the University of Louisville, Ky., and colleagues.
"What we have found here is a new set of mechanisms that have never been taken advantage of in a therapeutic way," Harkema said at a news conference held to announce the findings. "It opens a whole new set of possibilities for patients, not just those recently injured but those who have been injured for months and years."
Hard Work Leads to Success
The breakthrough did not happen overnight. It's the result of more than 30 years of animal research by a number of scientists. Prominent among them is Harkema's mentor and study partner, University of California, Los Angeles researcher V. Reggie Edgerton, PhD.
"When Rob regained voluntary control of his leg, I was afraid to believe it when I saw it," Edgerton said at the news conference. "What nobody has ever demonstrated is that epidural stimulation at modest levels enables an individual to have conscious control of body motion. Someone with paralysis for several years can now control his movement. This has never been done before."
Summers was a 20-year old pitcher for Oregon State's championship team. Late one night in July 2006, he was taking his gym bag out of his car when another car jumped the curb and knocked his legs out from under him. He woke up unable to move his legs or trunk, or to control his anal sphincter or bladder.
Eventually he found his way to TIRR Research Center in Houston, the same rehab center now treating Rep. Gabrielle Giffords. Harkema, at TIRR for a visit, met Summers and invited him to the Kentucky Spinal Cord Injury Research Center, where she is director.
Summers became the first of a planned five patients to receive the epidural stimulation device, originally designed and FDA-approved for pain relief. California Institute of Technology engineer Joel Burdick, PhD, adapted the device for spinal cord treatment. Jonathan Hodes, MD, chair of the University of Louisville department of neurosurgery, implanted the device into Summers' spine.
But it wasn't all the doctors' doing. Before getting the implant, Summers practiced trying to move for over 26 months in 170 training sessions. He never gave up -- but did not move until receiving the implant. On his third try, when Harkema's team found just the right level and pattern of electric stimulation, he was able to stand with only minimal support for balance.
Seven months later, he became able to move his legs on command, although he can neither stand nor move when the device is turned off. It's not designed to be left on all day, but that hasn't dimmed the young athlete's determination.
"Being able to move my ankles, my toes, my knees -- there are not enough words to describe how I felt after not having anything for four years," Summers said. "It was a dream and now it is a reality. I am going to work until I achieve all my goals. I have a long list: First to stand completely independently, then to take steps in a functional manner, and eventually to play baseball again."
Summers' treatment and hard work had an unexpected benefit: He regained control of his bowels and bladder, and told his doctors that he had regained sexual function.
"Not only has this given me more quality of life, but I have the confidence to get out in world and live my life," he said.
Spinal Injury Treatment Experimental, but Device Already on Market for Pain
Harkema and colleagues warn that the procedure remains experimental, and that the device implanted into Summers will have to be redesigned for spinal-cord treatment. They are not sure exactly which spinal-cord-injury patients can be helped with this technique and which can't.
But John McDonald, MD, director of the International Center for Spinal Cord Injury at Kennedy Krieger Institute, is eager to try the technique. McDonald worked with actor Christopher Reeve for several years after Reeve's devastating spinal cord injury.
"I'm already on board," McDonald tells WebMD. "This technology will really only help the 10 to 15 percent of people with spinal cord injury who are basically about to regain the ability to walk a short distance using walkers or braces. ... Eventually, everyone in that 10 to 15 percent is going to get one of these. To be able to offer this is what we dream of as physicians."
John Heller, MD, director of the spine fellowship training program at Emory University, participated in some of the early research into spinal stimulation in the 1980s. Like McDonald (but unlike Harkema), he sees no problem with surgical teams adapting the current device for treating spine-injury patients. But Heller is quick to point out the limitations of the Harkema/Edgerton technique.
"This would be a nice kind of end-around that would be a very helpful crutch to patients," Heller tells WebMD. "But because it depends on software and batteries and a gadget, it will never be the same as if we could re-establish the spine/brain connections nature engineered -- that is the Holy Grail of spinal injury research. While we will continue those efforts, if this is a leg up in the process, this is great."
The Harkema study was funded by the Christopher & Dana Reeve Foundation and by the National Institutes of Health. Harkema and colleagues report their findings in the May 20 online issue of The Lancet.