May 20, 2011
Experimental Treatment Has Paralyzed Man Standing, Walking
Rob Summers was left paralyzed after a car accident in 2006 but is now able to stand and take steps after electrical stimulation of his spinal cord in what researchers described as a breakthrough in treating paralyzing injuries, Reuters is reporting.
Summers, a 25-year-old former college baseball pitcher, can now also move his hips, knees, ankles and toes. He also regained some bladder and sexual functionality, researchers said on Thursday.
Susan Harkema, lead researcher of the study from the University of Louisville in Kentucky, explains, "It opens up a huge opportunity to improve the daily functioning of these individuals ... but we have a long road ahead."
"This is not a cure, and Rob's not walking. ... Short of that, this approach may have impact in incremental ways," she continued. "Allowing people to just stand a few minutes a day can dramatically change their health."
After 26 months of retraining the leg muscles, followed by the pioneering surgery, Summers can reach a standing position and support his own weight for up to four minutes at a time.
With a harness to support him and with some assistance from a therapist, he can make repeated stepping motions on a treadmill. He can also voluntarily move his toes, ankles, knees and hips on command. Summers, said he was ecstatic.
"This procedure has completely changed my life," he said. "For someone who for four years was unable to even move a toe, to have the freedom and ability to stand on my own is the most amazing feeling. To be able to pick up my foot and step down again was unbelievable, but beyond all of that, my sense of wellbeing has changed. My physique and muscle tone has improved greatly, so much that most people don't even believe I am paralyzed," AFP reports.
Paralysis comes from damage to the spinal cord down which the brain sends electrical signals along nerves instructing limb movement. This research focused on nerve networks in the lower spine that are relatively autonomous. They can follow through the commands for weight-bearing and coordinated stepping without input from the brain.
The mechanism works with feedback from nerves in the muscles of the legs and feet that is sent directly to the spinal cord. It is this sensory input that helps the individual to adjust his balance and speed of movement and level of weight-bearing in response to surfaces and inclines.
"The spinal cord can independently interpret these data and send movement instructions back to the legs -- all without cortical [cerebral] involvement," explained Reggie Edgerton, a professor of integrative biology and comparative physiology at the University of California, Los Angeles.
Sixteen electrodes were surgically implanted in the lumbosacral spinal cord, connecting them to thick nerve bundles that largely control movement of the ankles, hips, knees and toes. This sent down electrical signals mimicking those sent down the spine by the brain initiating movement.
With Summers, electrostimulation was part of sessions lasting up to 250 minutes.
The goal of this research is to allow at least some individuals with spinal paralysis to use a portable stimulation unit to stimulate normal movement and feeling. With the help of a walker, it is hoped, such patients would maintain balance and execute some effective stepping, AP reports.
There could be even greater secondary benefits, including perhaps the restoration of bladder and sphincter control and sexual response.
Summers is the only patient so far to undergo the treatment out of five authorized by the US Food and Drug Administration (FDA). While completely paralyzed below the chest, Summers was rated a "B" on the US classification of spinal injury, as he did retain some feeling below the point where the damage occurred.
It is unknown whether the procedure will work on "A" patients, who have no sensation below the injury. In addition, Summers is young and was extremely fit before his accident. Drugs are being developed to heighten the sensitivity and function of the spinal cord neural network, which could further enhance the technique.
The California Institute of Technology also contributed to his recovery. A paper detailing this work is published in The Lancet.
Image Caption: Rob Summers, 25, in the harness that provides support while he receives electrical stimulation to his spinal cord. The experimental procedure has allowed Summers to stand and move his legs voluntarily. Credit: Rob Summers
On the Net:
- University of Louisville
- University of California, Los Angeles
- California Institute of Technology
- The Lancet