High-Tech 'Exoskeleton' Can Give Mobility Back to People With MS
Most people take the ability to move for granted, but not Kathy Miska.
Miska has had multiple sclerosis for two decades now, and her ability to get around has deteriorated steadily.
Now, a new robotic exoskeleton is giving her an opportunity to regain some of the mobility she's lost to the degenerative nerve disease.
"You can definitely tell when you get out of the suit. It's easier to move," said the 56-year-old resident of Strongsville, Ohio. "I would have moments when I was at home, and I'd get up and it was like my leg was doing what it was supposed to be doing, and I hadn't seen that for a while. I'd be screaming to my husband, my leg's working! My leg's working!"
Miska is one of five patients at the Cleveland Clinic's Mellen Center for Multiple Sclerosis who are taking part in a trial to assess the potential effectiveness of a robotic exoskeleton in physical rehab.
These exoskeletons -- a metal frame with motors at the joints -- are already used to help people regain mobility after spinal cord injuries and stroke, said lead researcher Dr. Francois Bethoux, director of rehabilitation services at the center.
Building strength and range of motion
MS patients struggle with weakness and fatigue during rehab, Bethoux said, and researchers figured an exoskeleton would help extend their sessions beyond their normal capabilities.
"If we don't use the device, then when the person becomes fatigued or getting weaker, they have to stop for a rest period and they may not be able to walk again during their physical therapy session," he said. "Here, the device can provide some assistance."
The idea -- not yet proven -- is that the exoskeleton gives patients more opportunity to build their muscle strength and improve their range of motion, Bethoux said.
He added that researchers also hope the longer workout sessions will strengthen neural connections in the brain and spinal cord that have been damaged by MS, a concept called neuroplasticity.
"Mind you, that hasn't really been proven with the exoskeleton, but we know that neuroplasticity can happen with physical rehabilitation," Bethoux said. "The more repetitions of a movement we do, the more likely is it we can trigger neuroplasticity. That's where the device is strong. It allows more repetition of steps."
Tailored levels of assistance
A physical therapist straps a patient into the exoskeleton, which Bethoux said can cost as much as $150,000. An adjustable metal brace supports the legs, feet and torso, allowing people to stand without using their own strength.
Battery-powered motors drive the knee and hip joints, with the exoskeleton programmed to respond to the patient's body movement. Shifting weight toward the leg that will stay on the ground and initiating liftoff with the other foot causes the motors to engage.
"At the highest level of assistance, the device can basically walk for the person, actively moving the legs to produce the movements of walking," Bethoux said.
Physical therapists set the level to give patient the best possible workout and keep them moving. Patients use canes or walkers to maintain their balance.
One patient's story
Miska entered the study because she started using a walker about three years ago, and her doctor thought she would benefit from physical therapy. Cleveland Clinic had just gotten the exoskeleton thanks to a generous donor and grant money.
"My physical therapist thought I was a fantastic fit for it, because I still had some mobility," Miska said.
It was not easy to use the exoskeleton at first, she recalled.
"You have to kind of retrain your brain how to walk," Miska said. "My right leg is my very weak leg. I have difficulty with lifting my leg. In order to make a correct walk, you have to pick your leg up. I can't do that, so I would swing my right leg around to walk. When you swing your right leg out to walk, it forces you to the left to kind of counterbalance yourself."
Miska found she had to shift her weight way to the right in order to walk normally with the exoskeleton, with physical therapists providing help.
"By the end of the session, they would be working up a sweat trying to pull me over to the right to compensate for what I was doing," she said. "It was a huge learning curve."
Results from the therapy were immediately evident, however, and grew over the eight weeks when Miska engaged three days a week in hour-long sessions with the exoskeleton.
"When I was done, I was walking about 25% quicker and had better endurance and my gait was much more normal, so I was very excited," Miska said. "I'd get out of the suit and I would just notice right away it seemed a little easier to walk."
One of her physical therapists, Matthew Sutliff, attested to her improvement.
"It seems to be really making a difference in Kathy's gait training," he said in a Cleveland Clinic news release. "She has a lot of weakness in her right leg, but her left leg is a bit stronger. So we programmed the device to give her a fair amount of support for her right leg to teach the proper step pattern. As we continued, we slowly reduced assistance for the right leg, requiring her muscles to perform more of the work."
Miska lost a bit of her progress during a holiday vacation at a resort where she had to rely on a mobility scooter and walked less than usual.
"I feel like for the last month I was working to get back to where I was before my trip," she said. "I think I'm back there now."
Ways exoskeletons could help
Exoskeleton-assisted physical therapy could be very promising for some patients with MS, said Kathy Zackowski, the National MS Society's senior director of patient management, care and rehabilitation research.
"We need tools like this to get people to have a way to actively take part in their recovery and enjoy their life," she said. "We're not saying that medications aren't necessary, because they are. What we need are things people can do in addition that might actually help them recover."
Zackowski said the exoskeleton could relieve MS fatigue and weakness by helping a person build up muscles and become more fit.
"There is evidence that if people are as fit as possible, that does help their fatigue," said Zackowski, who did research into mobility and gait for 15 years at Johns Hopkins.
But she questions whether the exoskeleton would help MS patients whose mobility is affected by spasticity or ataxia. People with ataxia sway and have inconsistent steps -- a gait similar to someone who has had too much to drink.
"The people with these symptoms have very different kinds of movement, and I don't know if this device is set up to counter the forces that would be produced by the person," Zackowski said. "This device looks like it requires people to walk kind of in a straight line. I don't know how it deals with someone who had this ataxia problem, and it's a big problem. People get stopped on the street, because they think people are drunk, and they're not. They just have these terrible symptoms."
Bethoux agreed that more research is needed to learn which people would benefit most from the exoskeleton.
"It's likely it's not going to work for everyone, so we have to define the ideal benefit of someone who would benefit from the device," he said. "We also still don't know the dosing -- how many sessions of training are needed to provide an improvement in walking even after they stop using the device."
To get a better look at how the exoskeleton works, here's a video clip from the Cleveland Clinic:
The National MS Society has more about multiple sclerosis.
SOURCES: Kathy Miska, Strongsville, Ohio; Francois Bethoux, M.D., director, rehabilitation services, Mellen Center for MS Treatment and Research, Cleveland Clinic Foundation, Ohio; Kathy Zackowski, Ph.D., senior director, patient management, care and rehabilitation research, National Multiple Sclerosis Society; Cleveland Clinic, news release