Two out of four paralyzed patients who underwent an experimental electrode treatment and rigorous physical therapy regained the ability to walk with limited help, a University of Louisville team reported Monday.
The four patients had suffered a traumatic, motor complete spinal cord injury, meaning that they could not make voluntary movements below the injury site. All four were unable to move their legs for at least two-and-a-half years when they began treatment, which started with eight weeks of intense physical therapy. Physical therapy alone did not change their ability to walk.
Each patient went through two hours of training five days a week before an epidural stimulator was implanted below the injury site, between a bone in the spine and the spinal cord. Medtronic provided the 16-electrode stimulators—designed for pain control—and their associated programming and charging devices, but didn’t otherwise participate in or support the study. The report was published online in the New England Journal of Medicine.
About 20 days post-surgery, the researchers set about finding the best stimulation combinations that activated “ensembles of leg muscles that stimulated walking movements.” They settled on combinations that enhanced standing and stepping movements as patients focused on carrying out those tasks.
After treatment, all four patients regained trunk stability and were able to stand independently with a walker. Two patients were able to transition from walking on a treadmill to walking on the ground—one walked with horizontal poles or when holding hands with a person on either side, while the other walked using a walker and without help from trainers. The other two patients couldn’t walk on the ground, but were able to walk on the treadmill with their body weight supported.
None of them could do these actions when their stimulator was switched off, but their movements “were not driven solely by electrical stimulation.” Patients only stood or walked when they had the intention to move.
“The current study showed that recovery of walking, standing, and trunk mobility can occur under special circumstances with intensive training and electrical stimulation years after a spinal cord injury that caused complete leg paralysis,” the team wrote. “Persons with some degree of spared sensation below the level of injury may be more suitable candidates than those with no sensation, but this, and the durability of over-ground walking, requires investigation in larger groups of patients with spinal cord injury.”