Researchers at the Mayo Clinic in Rochester, Minn., have helped a man walk again, with some assistance, thanks to an electronic device implanted in his spine.
The man, now 29, had been paralyzed in a snowmobile accident four years before he started the experiment and had completely lost the ability to move his legs as well as all sensation in those limbs.
Study co-author Dr. Kendall Lee, director of the Mayo Clinic’s neural engineering laboratories, said the researchers wanted to know, “Could we get this patient to one, move the paralyzed leg in a voluntary way, and two, once we’ve achieved that, could we get the patient to stand and take independent steps?”
According to a paper published in Nature Medicine, the researchers were able to do both. “We were able to get him to stand independently and be able to take his own steps,” said Lee.
To get there, they placed an electronic stimulator in the patient’s spine, below the injury site. This stimulated the nerves in his spine, and after 43 weeks of therapy and tweaking of the device, in the end, he was able to take independent steps on a treadmill while supporting his body by holding onto a handrail. He was also able to take some steps using a walker, with occasional assistance from a personal trainer.
Although Lee thinks the study results are “very exciting,” the researchers actually aren’t sure how and why it works.
“The precise mechanism on how we were able to accomplish this in terms of the epidural stimulation is still not known.”
The researchers will continue to study this further to figure out exactly how it works and how it might be applied to others.
Spinal cord injury
That’s the trick, according to Dr. Eve Tsai, the Suruchi Bhargava chair in spinal cord and brain regeneration research at the Ottawa Hospital Research Institute.
“This is fantastic,” she said of the research. But, “whenever you have something like this though you always have to have a bit of reservation about it.”
The problem is that not all spinal cord injuries are the same. “The reality is with spinal cord injury, it’s really a huge spectrum,” she said. It can range from a mild loss of sensation to full loss of sensation and motor control.
So this particular advance is not going to be the “cure-all for everybody and there’s still a lot of work that needs to be done to sort out which patients might be helped, why they’re getting this improvement and maybe we can tailor it to each individual person and have it work out better for each individual person.”
The nervous system isn’t as simple as a wire running from the brain to each muscle, she said. Some of the functions that help us move our limbs are actually partly located in the spinal cord itself, which is why electronic stimulation of that area might be having an effect, by inducing a “reflex” action, she thinks.
Lee believes his team’s research is “highly significant because if you look at all the research that has been done over the past five years in trying to regain functional control back, there really has not been very much success.”
Even just having one patient able to regain this voluntary control of his legs is a good advance, he thinks, though there is a lot of research left to do.