NIH Study: Spinal Stimulation Helps Paraplegic Patients Regain Voluntary Movement
Groundbreaking results offer new hope for patients with spinal cord injury
Four people with paraplegia are able to voluntarily move previously paralyzed muscles as a result of a new therapy that involves electrical stimulation of the spinal cord, according to a new study funded in part by the National Institutes of Health.
The participants, each of whom had been paralyzed for more than 2 years, were able to voluntarily flex their toes, ankles, and knees while the stimulator was active, and the movements were enhanced over time when combined with physical rehabilitation. Researchers involved in the study say the therapy has the potential to change the prognosis of people with paralysis even years after injury.
The study is the continuation of a groundbreaking pilot trial initiated in 2009 to determine whether spinal stimulation, in conjunction with daily training on a treadmill, could help patients with paralysis regain some ability to move. In that trial, a young man paralyzed below his chest had a 16-electrode array implanted on his spinal cord. He then underwent daily training in which he was suspended in a harness over a treadmill while a team of researchers supported his legs, helping him to either stand or walk. At the same time, the array delivered electrical pulses to his spinal cord just below his injury.
According to the researchers, the goal of the stimulation was to increase the sensitivity of local circuits within the spinal cord that carry out basic motor functions without input from the brain — such as the knee jerk that occurs after stepping on a tack, or even more complex patterned movements, such as stepping. While not strong enough to directly induce muscle activation by itself, the researchers believed the stimulation could lead to movement when combined with sensory input from stepping on a treadmill.
In the new follow-up study, Claudia Angeli, PhD, and her colleagues report that three additional patients with paralysis have recovered voluntary muscle control after electrical stimulation of the spine. Their report was published in the April 8 online issue of Brain.
The three patients in the new study include two with complete motor and sensory paralysis and one with complete motor paralysis but some ability to experience sensation below his injury. Within a few days of the start of stimulation, all three patients regained some voluntary control of previously paralyzed muscles.
“This is a wake-up call for how we see motor complete spinal cord injury,” said V. Reggie Edgerton, PhD, the researcher responsible for developing the new approach to rehabilitation. “We don’t have to necessarily rely on regrowth of nerves in order to regain function. The fact that we’ve observed this in all four patients suggests that this is actually a common phenomenon in those with complete paralysis.”
Source: NIH; April 8, 2014.