For the first time, a man completely paralyzed from the chest down regained the ability to take several steps with support and stand on his own thanks to electric stimulation to his spinal cord, new research published in the Lancet shows.
Rob Summers, 25, was paralyzed in 2006 after being hit by a car that jumped the curb. After undergoing intensive motion training, an electrical pulse generator that mimics the brain’s signals for movement was implanted in his back and Summers was able to regain some voluntary motion during stimulation sessions that lasted up to two hours.
It was the first time electric stimulation produced this result in a human, though previous tests on animals showed similar results.
Watch Summers after the therapy:
Summers stands with electric stimulation:
“I think this is a real game-changer,” said Susan Howley, executive vice president for research at the Christopher & Dana Reeve Foundation, which helped fund the study conducted by researchers at the University of Louisville and the University of California, Los Angeles.
“I think it opens the door very wide for further exploration and potentially changes daily life for many people with spinal cord injuries,” she 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.”
Rob Summers, study patient
Patients who could benefit the most are likely those with a similar degree of injury to Summers, said Ali Bydon, director of the Johns Hopkins Spinal Column Biomechanics & Surgical Outcomes Laboratory, who was not involved in the research. Summers’ spinal injury was categorized as a level B, because he retained some feeling below the point of injury, though he had no motor ability. Patients rated with an injury level of A retain no motor ability and no sensory ability.
“This is ground-breaking research,” said Bydon. “The brain is completely bypassed in this research, [signal] is going from the legs to the stimulator and back.”
The signals sent by the electric stimulator, which provided continuous electrical current during sessions at up to 10 volts, had to work in concert with the spinal cord’s own neural network and the sensory input coming from the patient’s legs in order to create the muscle movements seen in the study.
Summers told researchers he could always feel when the stimulation was on, usually from a tingling sensation at the site, but that the feeling never reached discomfort or pain.
The findings could help guide future spinal cord injury research, though the study authors caution that the results must be replicated in other paraplegic patients and further study is needed.
“We are in the very, very early stages of really understanding the best way to activate the circuitry” in the spinal cord, said Susan Harkema, one of the study authors and the rehabilitation research director at the Kentucky Spinal Cord Injury Research Center. “The most important finding right now is that we can access this circuitry.”
Another vital component to the result was the two years of motion training Summers underwent in order to re-teach the neural network of the spine to produce the movements.
“The spinal cord is able to learn. The way a child does not just get up and walk, an injured spinal cord is a new spinal cord and has to be trained to do things,” said Michael Sofroniew, a professor of neurobiology at UCLA’s School of Medicine, who was not involved in the study but has conducted similar studies in animals.
The spinal cord has a large capacity for reorganization, he said, allowing it to reorganize itself and make use of signal it receives from a new source to drive movement.
For his part, Rob Summers says the treatment was life-changing.
“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,” he said in a statement. “My physique and muscle tone has improved greatly, so much that most people don’t even believe I am paralyzed. I believe that epidural stimulation will get me out of this chair.”
But Bydon cautions it may be too early to hope that the same results can be seen in other patients.
“It is good, it’s reassuring,” he said. “It is too early to say we are going to beat the dire effects of spinal cord injury.”