A new non-invasive spinal cord stimulation technique has helped five men with complete paralysis who, with training, were able to move their legs, say researchers at the University of California Los Angeles (UCLA), the University of California – San Francisco, and the Pavlov Institute in St. Petersburg, Russia. The study was announced on July 30, 2015 and the findings were published in the Journal of Neurotrauma.
The new method, known as transcutaneous stimulation, uses electrodes strategically placed on the skin of the lower back to deliver an electrical current to the spinal cord. The study participants were able to voluntarily produce step-like movements. This is the first time that anon-invasive technique has been used to spur movement. In a previous study by researchers at the University of Louisville, UCLA and the Pavlov Institute of Physiology, electrodes were surgically implanted on the spinal cord.
During the current study, the men moved their legs while their legs were suspended by braces that were hung from the ceiling. This arrangement allowed the men to move freely without resistance from gravity. Researchers say that this environment cannot be compared with walking, but demonstrated significant progress towards developing therapies for people with spinal cord injuries.
The five participants ranged in age from 19 to 56 and had been paralyzed for more than two years due to athletic injuries, or in one case, an auto accident. They attended 45 minute sessions once a week for approximately 18 weeks so that researchers can analyze how the non-invasive electrical stimulation affected their ability to move their legs. The participants also received several minutes of conditioning in every session through the manual moving of their legs in a step-like pattern. Researchers studied the conditioning to determine if physical training in addition to electrical stimulation enhanced the men’s ability to move voluntarily.
At the beginning of the study, movement only occurred when the stimulation was strong enough to generate involuntary step-like movements. After four weeks of receiving stimulation and physical training, the men were able to double their legs’ range of motion during stimulation. The researchers recorded the electrical signals generated by the calf and muscle directly below the calf while the men tried to flex their feet. Researchers say the result suggest that the electrical stimulation may be able to reawaken dormant connections between the spinal cord and the brain.
During the final four weeks of the study, the men were given the drug buspirone, which is often used to treat anxiety disorders. During stimulation, the men were told at various times to either remain still or to move their legs. The electrical charges did not cause discomfort in the patients. By the end of the study, the participants could move their legs without stimulation, and had the same ability to move as they did while receiving stimulation. “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,” said V. Reggie Edgerton, senior author of the study and a UCLA professor of integrative biology and physiology, neurobiology and neurosurgery.
“These encouraging results provide continued evidence that spinal cord injury may no longer mean a lifelong sentence of paralysis and support the need for more research,” said Roderic Pettigrew, Ph.D., M.D., director of the National Institute of Biomedical Imaging and Bioengineering at the National Institute of Health. “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. It’s a wonderful example of the power that comes from combining advances in basic biological research with technological innovation.”