A study has found that three paraplegics and one quadriplegic, each of whom had been paralyzed for over two years as a result of a spinal cord injury, can now voluntarily flex their knees, ankles and toes through epidural stimulation. Combined with physical rehabilitation, the movements were also enhanced over time. The breakthrough, which built upon the results of an earlier study, was reported in the April 8 online issue of the neurology journal Brain.
The results of this recent study, which comes from researchers at the University of Louisville, UCLA and the Pavlov Institute of Physiology, indicate that epidural stimulation therapy may help people with paralysis even years after injury. It also includes new results from tests conducted on Rob Summers. The initial study was published in The Lancet in 2011 and was based on Summers’ participation in a 2009 pilot trial evaluating the effects of epidural stimulation in conjunction with daily treadmill training. Summers had an electric nerve stimulator implanted in his spine that, when turned on, helped him use his own nerve impulses to move his muscles. Summers was able to stand three days after surgery and take his first steps nine months later. Currently, Summers uses a wheelchair on a day-to-day basis but is able to stand for 90 minutes.
The Brain study was funded by the Christopher and Dana Reeves Foundation and the National Intstitutes of Health (NIH). Director of the NIH National Institute of Biomedical Imaging and Bioengineering (NIBIB) Roderic Pettigrew, Ph.D., M.D. said that the astounding results of the 2009 study caused researchers to be “cautiously optimistic.” The 2014 followup study has repeated those results in four out of four patients. Pettigrew said the new study results suggest that “a large cohort of individuals, previously with little realistic hope of any meaningful recovery from spinal cord injury, may benefit from this intervention.” Out of the four subjects, two were diagnosed as being complete sensory and motor injured “with no chance of recovery at all,” said Claudia Angeli, Ph.D., who is an assistant professor at University of Louisville’s Kentucky Spinal Cord Injury Research Center. When the stimulator was implanted and activated in the patients, they were all immediately able to move their knees, ankles, and toes as well as independently bear weight.
The participants’ recovery time was so brief that researchers are now speculating that some nerve pathways, after injury, might still be intact. UCLA distinguished professor of integrative biology, physiology, and neurobiology V. Reggie Edgerton, Ph.D., who has been conducting research in spinal cord injury for 38 years, said that the study’s results are “a wake-up call for how we see motor complete spinal cord injury.” The regrowth of nerves is not necessarily a prerequisite for regaining function, said Edgerton, because function without regrowth was observed in four out of four participants. Edgerton went on to say it “suggests that this is actually a common phenomenon in those diagnosed with complete paralysis.”
The belief that complete paralysis is permanent has now been challenged. There is strong evidence, said Dr. Angeli, that continued advancements of the epidural stimulator will enable complete spinal cord injury individuals to be able to work towards stepping. Executive vice president of research at the Christopher & Dana Reeves Foundation, Susan Howley said in a statement on the foundation’s website that the followup study shows the findings of the 2011 The Lancet pilot study “were not an anomaly.” Howley added that the study’s implications “are quite profound” given that currently “there are no effective evidence-based treatments for chronic spinal cord injury.” Epidural stimulation may become “part of a cocktail of therapies used to treat paralysis,” said Howley.
By Donna Westlund