A common implant designed to stimulate the spinal cord is allowing paralyzed patients to move again — a first-of-its-kind finding in a clinical trial at HCMC in Minneapolis.
While results have varied among about 20 trial participants, the takeaway so far is that people can regain function after spinal cord injuries and not merely maintain whatever limited mobility they have, said Dr. David Darrow, the lead investigator.
The trial could be the first that compels the U.S. Food and Drug Administration to approve a device that restores function after spinal cord injuries, he said. "So this, using neuromodulation, is exciting, because if we get a positive change then hopefully it means we can parlay that into bigger and bigger changes."
Crystal LaBo was proof Thursday at her third follow-up appointment at HCMC after having the stimulator implanted in March. When the device is active at certain settings, she can lift her legs and bend her ankles — limbs that had been immobile for 23 years after LaBo was injured in a car accident.
While relatives and friends are amazed by her newfound movements, LaBo said they are largely for show because she can't yet put enough pressure on her legs to stand or walk. Far more meaningful are the hidden benefits. The stimulation has stabilized her blood pressure, eliminated extreme temperature swings and allowed her to urinate without using a catheter.
"That was more of a big deal to me than moving my legs," she said. "I know that might sound strange."
LaBo, who's 41 and lives in northern Ohio, had been searching for options to regain mobility for years, but most studies required patients with recent spinal cord injuries. She was about to pursue a trial in Indonesia before she found the HCMC study, called E-STAND. The acronym stands for Epidural Stimulation After Neurologic Damage.
LaBo maintains an active, independent lifestyle as the mother of four children and the co-owner with her husband of two gourmet grilled cheese restaurants. She cooks and serves food from her wheelchair frequently when staffing is short. But she has always hoped for more.
"I've always had the mindset that I would walk again one day," she said. "I don't know that I thought it would be like this, but I'm happy about it. I knew eventually one day somebody would come up with something."
Darrow said FDA approval could be swift if the HCMC trial succeeds, because the stimulator is widely used for pain management.
Most people with severe spinal cord injuries only have a fraction of their nerve fibers still capable of sending signals from the brain to lower limbs, Darrow said.
"Clinically we don't see any movement, we don't see any function at all," he said. "When we turn on the stimulation on the bottom of the spinal cord, it's actually changing how receptive it is to those remaining fibers. … We're just revving up the spinal cord so it's better able to receive."
The stimulation tends to improve motor function but not sensation, so patients such as LaBo learn to move again with their eyes rather than with their feelings and instincts.
"I'm really moving my feet, but I can't feel it," LaBo said during Thursday's exam. "So, am I really moving? It's a mental game with myself."
Patients enroll in the study for 13 months and participate in monthly visits. Each time they are sent home with a new range of stimulation settings so researchers can learn which ones are most effective.
Patients can turn the stimulator on and off, which LaBo said is helpful because the device can sometimes prompt sudden involuntary movements. She doesn't dare set a tray of food on her lap with the stimulator on — not since a leg twitch catapulted one into her face.
LaBo said progress has been steady but slow. Her family and friends created a whiteboard of future goals if she can continue to regain mobility. Her husband and all four of her kids want her to bowl standing up again.
"She may not realize it, but she looks like a kid at Christmas" whenever she achieves a new level of movement, said her husband, Dustin LaBo.
The study is dispelling myths that patients with older injuries can't make progress, Darrow said. What's unclear is whether patients will need stimulation permanently.
Darrow said about half the patients in the trial report some gains when their stimulators are off, but not at the level of motion with the stimulators. The research group's most recent study found increased muscle activation and coordination in trial participants.
"We see a building effect over time with more and more stimulation," he said. "So, I think that it will still require stimulation, but that's a hard question at this point."