Using a medical device invented to treat back pain, researchers have discovered a way for paraplegics to move their legs.
The discovery represents a game-changing shift in the treatment of paralysis, said Peter Wilderotter, president of the Short Hills-based Christopher & Dana Reeve Foundation, which helped fund the research.
"The old dogma used to be that whatever movement you got back in the first couple of months after your injury was all you could expect," he said.
Now doctors have proved that some spinal nerves can be coaxed back to work even years after injury. Those nerves weren’t destroyed, it seems, but merely dormant, Wilderotter said.
"It’s truly a significant breakthrough," he said.
The technique involves surgically implanting the small pliable strip with 16 tiny electrodes against the spinal cord just below the injury site. Very low electrical current is then used to stimulate the spinal cord — mimicking the way the brain sends commands.
"It’s giving the circuitry a little nudge, saying, ‘Remember? This is what you used to do’," said Grace C.Y. Peng, program director of rehabilitation engineering at the National Institute of Biomedical Imaging and Bioengineering, which helped fund the experiment.
A battery pack is placed inside the abdominal cavity, which in turn is activated by a remote control held by the patient.
The four men who participated in the study had been injured in motorcycle or car accidents more than two years before their treatments. During the treatments, they were able to move their legs, hips and toes.
Even better, the participants needed less electrical stimulation in subsequent treatment sessions — a change that meant the spinal network was proving its ability to learn.
Given the experiment’s success rate of four-out-of-four, researchers were hopeful the technique would help many other paraplegics. For that reason, they tested it on four tough cases.
"They picked subjects who were the most injured who were diagnosed as never being able to move again," said Peng.
The ability to walk remains a long way off, however, researchers say. Controlling leg muscles is different from being able to stand up, balance, and bear weight. And all of those skills must be in place before a patient could attempt even a single step.
Thirty years ago, the belief that the spinal cord is smart enough to have some kind of memory of its own was considered "junk science," Wilderotter said. So ingrained is the belief that injury-damaged nerves are gone for good that when visiting researchers see a patient move his legs on his own, he said, "their mouths drop."
The findings were published in Monday’s medical journal Brain. The research was conducted mostly at the University of Louisville’s Kentucky Spinal Cord Injury Research Center.
The device is not commercially available. For now, its use is limited to patients in the clinical trial.
Now that is has been proved that stimulation can reawaken damaged nerves that control the legs, Peng said researchers are now studying whether they can reproduce the same success for paralyzed arms.
"It took us 30 years to reach this point, so it’s an extremely exciting advancement, Wilderotter. "And it’s not going to take us another 30 years to get to the next point."
Christopher Reeve, who played "Superman" and other roles in movies, was left paralyzed from the shoulders down after breaking his neck in a fall from a horse in 1995.
He started a concentrated program of exercise and electrical muscle stimulation in 1999, and doctors later said he had enjoyed a slow rebirth of limited sensation and movement. That type of stimulation was aimed at his muscles, not the spinal cord, as was this newer experiment. The 52-year-old Reeve died in 2004.