||Last Updated: Feb 4, 2015 - 12:35:55 PM
Sometimes research brings about unexpected outcomes. Such seems to be the case for Susan Harkema, a neuroscientist at University of Louisville. This study was funded by the Christopher and Dana Reeve Foundation, and is being published in the scientific journal Brain. She was studying the effects of sending electrical stimulation to broken spinal cords in hopes of learning more about nerve pathways. But along the way, her research subjects started showing what she thought were involuntary spasms.
One of her subjects, Rob Summers demonstrated these spasms. When asked to lie down and close his eyes, Harkema told him to move his toes…first his right toes, then his left. The surprise was that he could do it on command, ruling out the involuntary spasm theory. Over the next five years, Harkema’s team applied electrical stimulation to three more paralyzed men and all of them, including Summers, were able to wiggle their toes, lift and swing their legs, move their ankles and sit up without support. Two of the subjects were even able to do sit-ups.
It's not the first time electrical stimulation has made paralyzed patients move, but Harkema says it's the first time electrical stimulation directly to the spinal cord has shown voluntary activity. Experts say this new technique is another piece of the puzzle toward helping paralyzed people walk again. And it's another avenue doctors can go down to try to help these patients.
Dr. Barth Green, co-founder of the Miami Project to Cure Paralysis at the University of Miami calls this research “a breakthrough”. It shows that you can have a living spinal cord under the layer of the injury.
More than 1,700 paralyzed people have inquired about using this technology, which involves surgically implanting a stimulator and giving it directions with an external remote control. The stimulator creates a small, slightly visible bulge in the lower abdomen and is connected to wires that send electrical pulses to the spinal cord.
But patients shouldn't expect that the stimulator will help them walk -- at least not now and maybe not ever. The stimulator can only make one leg work at a time. Patients have to turn the stimulator off and then back on again to make the other leg work or to make another set of muscles such as their torsos work.
Even though the stimulation doesn’t allow for walking, it does have some other benefits. For some patients it dramatically improved bladder, bowel and sexual function. Also, tests showed that the patients, some of whom had been paralyzed for many years, were able to move their legs and torsos in addition to becoming healthier in general with improved heart and respiratory functioning.
If you can change health and wellness and life expectancy, to me that's a home run," Green says. "Remember, Christopher Reeve died from complications of immobility,"
The researchers are pretty much stumped as to exactly why electrical stimulation to the spinal cord created the movement on demand -- after all, they didn't touch the patients' brains.
Perhaps, Harkema says, the spinal cord in a way has a brain of its own.
"Maybe the spinal cord makes the decision to move on its own and then executes the movement," Harkema says. "Otherwise I don't know how you would see what we see today."
The Louisville researchers now have funding to implant the device in eight more patients. They hope a device company will help them come up with a way to stimulate more than one muscle group at a time.
"I think what's incredibly exciting is we've opened up a realm of possibilities of what we can do now with people who are paralyzed, and we've just scratched the surface," she says.
Quotation of the Week
“That is the essence of science: ask an impertinent question, and you are on your way to the pertinent answer.”
Jacob Bronowski, The Ascent of Man, 1973
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