Electrical Stimulation Offers Hope for People With Severe Spinal Cord Injury
Spinal Cord Injury Research Update
Electrical stimulation is giving new hope to people with severe spinal cord injury. A recent study shows that four young men with paraplegia are now able to move their legs on their own with the help of electrical stimulation of the spine. Researchers believe the therapy has the potential to change the prognosis of people with paralysis even years after injury.
The men, who had been paralyzed for more than 2 years, were able to able flex their toes, ankles, and knees while using electric stimulation. An even greater improvement in movement was found when the men used the stimulation in combination with physical rehabilitation. Details on this groundbreaking discovery were published in the April 8 issue of Brain.
The discovery “offers a new outlook that the spinal cord, even after a severe injury, has great potential for functional recovery,” said lead investigator Claudia Angeli, Ph.D., senior researcher, Human Locomotor Research Center at Frazier Rehab Institute, and assistant professor, University of Louisville’s Kentucky Spinal Cord Injury Research Center (KSCIRC).
How Electrical Stimulation Works
Electrical stimulation involves pulses of electricity that are sent down the spine to mimic the signals the brain normally sends to initiate movement. The electrical pulses are delivered through a stimulator that is surgically placed on the spinal cord.
Rob Summers, who is paralyzed below his chest, was the first person to benefit from this treatment. He received electrical pulses to his spinal cord just below the injury while undergoing daily training in which he was suspended in a harness over a treadmill while researchers helped him either stand or walk. Eventually, Rob could stand on his own for up to 4 minutes. Seven months into the trial, Rob regained some voluntary control of his legs.
Above: Kent Stephenson, the second person to undergo epidural stimulation of the spinal cord, voluntarily raises his leg while his stimulator is active. Photo courtesy of the University of Louisville.
All the men were able to synchronize leg, ankle, and toe movements in unison with a visual cue of the rise and fall of a wave shown on a computer screen, and three out of the four were able to change the force at which they flexed their leg, depending on the intensity of three different auditory cues.
“The fact that the brain is able to take advantage of the few connections that may be remaining, and then process this complicated visual, auditory, and perceptual information, is pretty amazing. It tells us that the information from the brain is getting to the right place in the spinal cord, so that the person can control, with fairly impressive accuracy, the nature of the movement,” said V. Reggie Edgerton, PhD, the researcher responsible for developing this approach to therapy. Dr. Edgerton is Distinguished Professor of Integrative Biology, Physiology, Neurobiology, and Neurosurgery at the University of California, Los Angeles.
Other Health Improvements
All four of the men were able to bear their own weight on their own and also showed other health improvements, such as increased muscle mass, less fatigue, and a greater sense of well-being. Rob, for example, Rob began to have better blood pressure control, body temperature regulation, bladder control, and sexual function.
The researchers are studying whether epidural stimulation can be used to help people with paralysis of the arms and developing a technology to deliver spinal stimulation through the skin rather than having to surgically implant the stimulator. In addition, researchers are working to advance electrical stimulator technology to help achieve greater control of movement in people with paralysis.
Angeli CA, Edgerton VR, Gerasimenko YP, Harkema SJ. Brain. 2014. doi:10.1093/brain/awu038.
National Institutes of Health. Spinal stimulation helps four patients with paraplegia regain voluntary movement. http://www.nih.gov/news/health/apr2014/nibib-08.htm. Accessed April 8, 2014.
University of Louisville. Four paraplegic men voluntarily move their legs, an 'unprecedented breakthrough' for paralysis community. http://louisville.edu/medicine/news/four-paraplegic-men-voluntarily-move-their-legs-an-unprecedented-breakthrough-for-paralysis-community. Accessed April 8, 2014.