For the first time, doctors have found a way to help completely paralyzed patients regain voluntary movement -- without surgery.
A new technique called transcutaneous stimulation helped five paralyzed patients move their own legs after several weeks of gradually increased re-training using electrical stimulation, physical therapy and an experimental drug. This is another step in early research into how paralyzed people may be able to regain some function.
"These encouraging results provide continued evidence that spinal cord injury may no longer mean a life-long sentence of paralysis and support the need for more research," Dr. Roderic Pettigrew, director of the National Institute of Biomedical Imaging and Bioengineering at the National Institutes of Health, said in a statement.
The study, published in the Journal of Neurotrauma, involved five men who had been paralyzed for two to six years, working with researchers at the University of California, Los Angeles; the University of California, San Francisco; and the Pavlov Institute in St. Petersburg, Russia. It was partially funded by the National Institutes of Health.
The technique researchers developed built on a previous study which showed that the spines of paralyzed patients still have functional potential that can be unlocked by electrical stimulation. The first study showed four patients who received an implant of electrodes in their spine were able to regain some leg movement. Research with amputees has also shown that attaching electrodes to active muscles or nerves can help them manipulate prosthetics.
Researchers in this study wanted to find a way to produce similar results without the trauma and cost of further surgeries.
"The potential to offer a life-changing therapy to patients without requiring surgery would be a major advance; it could greatly expand the number of individuals who might benefit from spinal stimulation," said Pettigrew. "It's a wonderful example of the power that comes from combining advances in basic biological research with technological innovation."
In 45-minute sessions that took place once a week, doctors placed the patients' legs in a "gravity-neutral" position attached to braces hung from the ceiling.
First, they placed electrodes over the skin of the patients' lower backs, which stimulated nerves that control the legs. In the early weeks, the men could only move their legs slightly, even with electrical stimulation, but gradually gained more capacity.
The men received physical training to re-learn a stepping motion, along with electrical stimulation, in each session. In the last few weeks, doctors added the experimental drug buspirone, which has been shown to help mice with spinal cord injuries.
Researchers say the men doubled their range of motion after four weeks when they voluntarily moved their legs while receiving the electrical stimulation. When the drug was added, the men were able to move their legs unassisted at the same level as they did when receiving electrical stimulation and training.
They say the entire therapy process may have helped the men to reconnect some signals between their brain and spinal cord, which retrained their bodies to make partial stepping motions -- without surgery.
"It's as if we've reawakened some networks so that once the individuals learned how to use those networks, they become less dependent and even independent of the stimulation," lead author of the original study, Dr. V. Reggie Edgerton, professor of integrative biology and physiology at UCLA, said in a statement.
Though no technique has been proven to help any group of paralyzed patients walk again, this research is part of a larger group of studies working to help them regain some function. More research on retraining the brain, body and nervous connections of paralyzed patients will be necessary. Researchers say they will need to test these therapies further and work to develop specialized plans for the wide range of partially and completely paralyzed people.
"All patients are going to need something slightly different, and maybe non-invasive stimulation is going to be best in some cases and epidural stimulation in others," said Edgerton. "What we need to do is maximize the clinical tool box that we have so that the physician and the patient can select a therapy that is best for them."