Epidural stimulation can help paralyzed patients learn to walk again

University
of Louisville

• Researchers at the University of Louisville’s Kentucky
  Spinal Cord Injury Research Center have helped two paralyzed
  individuals regain the ability to walk on their own.
• They implanted a device that sends an electrical current into
  the spinal cord, and also trained patients to relearn to stand
  and walk.
• Other patients have also regained the ability to move their
  legs or stand with this new technique.
• The researchers behind the study think they’re getting better
  at helping people learn to move again, and want to try these
  implants and training techniques on others with spinal cord
  injuries.

Kelly Thomas raced in rodeos, played soccer, and worked on her
family’s farm in Florida until July of 2014, when a car crash
left her paralyzed from the waist down.

She was 19 years old and doctors told her that she’d never walk
again.

But Thomas has now taken steps on her own once more, thanks to an
innovative medical technique developed by researchers from the
University of Louisville’s Kentucky Spinal Cord Injury Research
Center. The treatment involves an implant that delivers
electrical stimulation directly to the the spinal cord — along
with a whole lot of training where researchers help patients go
through the motions of standing and walking again.

“One day we were ‘walking’ and, you know, they were helping me as
usual. Then they stopped helping me and I took maybe three or
four steps in sequence. And I just stopped,” Thomas
explained in a video released by the University of
Louisville. “My lip started quivering, and my face got hot, and
my eyes got teary, and I was like, ‘Oh my God, that just
happened.’ I just took steps.”

There have been previous trials with this treatment. But in this
latest round of experiments, two of the four patients that
received the implants and training actually regained the ability
to walk — the first time that this treatment has made that
possible.

A
study describing the results was published Monday in the New
England Journal of Medicine. It indicates that many more of
the 1,275,000 people in the US paralyzed with spinal cord
injuries may eventually regain some of that function thought to
be lost forever.

Thomas was one of two patients to regain the ability to walk. The
other, Jeff Marquis, had suffered an even more severe spinal cord
injury from a mountain biking accident that left him paralyzed
from the neck down.

“It was really amazing. You get to see the little small
increments on a daily basis or a weekly basis, and then when it
all comes together that is a very emotional time for the
participants, and for the team as well in the sense that okay —
we got it, we’re able to put the pieces of the puzzle together,”
Claudia Angeli, one of the lead researchers behind the study,
told Business Insider.

Thomas relearning to move
independently.

University of
Louisville/YouTube

Rewiring the spinal cord

Angeli and colleagues have been working on this treatment for
years now. All in all, at least 14 patients have received some
form of training and epidural implant. In every case, patients
have recovered at least some ability to independently move parts
of their body they previously didn’t have control over.

The researchers chose the four participants for this most recent
study because they had similar injuries to four other previous
patients, whose results were described
in a 2014 study.

The research team has learned from each experiment how to better
implement their treatment in the future.

For the set of experiments described in 2014, patients were given
training in learning to stand. This training, called “locomotor
training,” involves researchers helping move patients’ bodies so
they again become familiar with the motion. Once they received
epidural stimulation — meaning they had implants installed that
send a small electrical current into the spinal cord — patients
were able to stand, but unable to walk.

For this newest set of experiments, the locomotor training
alternated between going through standing motions and walking
motions throughout a training period that extended for months
both before and after receiving the implant.

Angeli thinks that because both the standing and walking pathways
were trained from the start, Thomas and Marquis were able to
regain the ability to walk as well as stand.

It’s not the stimulation alone that triggers the change, however.
As Angeli explains it, the spinal cord is basically the conduit
for information between the brain and the rest of the body. The
brain provides the impulse to walk, while the body creates the
feeling of the ground underneath your feet.

Spinal cord injuries seem to impede this communication. But
electrical stimulation helps the spinal cord organize and
coordinate this process, putting the ability to walk again within
reach.

“It’s a matter of training,” Angeli said. “One of the big
findings is that we know the spinal cord has the capacity to
relearn. It’s very plastic, as long as you train it and give it
the right input.”

Stepping toward the future

Thomas and Marquis had severe injuries, but both still had some
sensation in their lower bodies; they couldn’t move, but could
feel certain forms of touch.

The two patients who didn’t progress as far had no sensation.
Still, those patients were able to stand, move a leg, or step on
a treadmill. Angeli said that it’s still possible these
patients could progress further with more training, which the
researchers plan to offer.

Thomas told CNN that with the electrical stimulation device,
she’s regained sexual function and some bladder control, but she
still wants more — she wants to be able to get on her horse,
Shadow, and take her to a gallop.

“That’s the day I’ll accept that I’m healed,” she said.

Angeli said the researchers want to see what happens if they put
epidural stimulators in patients with other types of spinal cord
injuries.

“We know the spinal cord can now do this thing, it can regain the
ability to walk,” she said. “That is huge. We need to be able to
reproduce this in a larger number of individuals with different
injuries and different time since injuries.”