Help stroke patients regain hand movement

Heather Rendulic had a stroke when she was 23 that left her left side paralyzed. Ten years later, her left arm and her left hand remain so disabled that she can’t tie her shoelaces, type with her two hands, or cut food herself.

But one insane month while participating in groundbreaking research, she suddenly found herself able to open padlocks with a key, draw a map of Italy, dip chicken nuggets in sauce, and eat them with a fork. It is now possible.

“It really did look like it had two arms, oh my god!” Lendulik said recently.

Researchers at the University of Pittsburgh and Carnegie Mellon University implanted electrodes along her spinal cord to provide electrical stimulation while she attempted various activities. Stimulation made her left arm more mobile and her fingers more dexterous, allowing her to make deliberate movements more quickly and smoothly.

the study, published on monday The journal Nature Medicine presents the first successful demonstration of spinal cord stimulation to address weakness and paralysis in the arms and hands of stroke patients.

The study was small and preliminary, involving only Rendulic and one other patient. Some scientists said many questions remain about the technology’s effectiveness and applicability, but research suggests that spinal cord stimulation could ultimately help some of the many people who have had a stroke. It suggests.

“I think it makes a lot of sense to improve quality of life,” said Lumy Sawaki-Adams, Ph.D., program director of the Division of Clinical Research at the National Institute of Neurological Disorders and Stroke. Still, she said, “When you think we’re not there yet, we have to be careful that we don’t offer hope to many people.

Spinal cord stimulation has been used for decades to treat chronic pain. Recently, some stimulating experiments have been conducted. surgically implanted electrodes again Non-invasively via electrodes placed on the skin — Shows promise for treating patients with spinal cord injuries regain leg mobility Sometimes arms and hands too.

However, neurologists say this approach has been largely unstudied for stroke, in part because of differences in the location and type of injury.

Strokes occur in the brain, so adding stimulation outside the brain wasn’t considered “just as cost-effective,” says Shirley Ryan, executive director of the technology and innovation hub at the rehabilitation center Ability Labs. Arun Jayaraman said. in Chicago. Although he was not involved, the study refutes that assumption and suggests that stimulating the spine, the pathway from the brain to the muscles of the hands and arms, may help with limb disorders. said.

more than every year 12 million people worldwide and About 800,000 in the US Karen Fury, Ph.D., vice chair of the American Stroke Association’s Stroke and Brain Health Sciences Subcommittee, said:

Initially, patients typically undergo about six months of physical, occupational, and other therapy, after which progress is often stagnant.

Dr. Furie, who is also chairman of the Department of Neurology at Warren-Alpert School of Medicine at Brown University and was not involved in the study, said:

About three-quarters of stroke patients experience dysfunction, weakness, or numbness in their arms and hands, said Dr. Elliott Ross, attending physician at the Brain Innovation Center at Shirley Ryan Ability Labs. He was not involved in this research. “For many people, it is the most difficult part of the stroke recovery process and tends to be the slowest to recover from.

Patients in this study had experienced different types of stroke and had varying degrees of disability. Lendulik’s stroke was hemorrhagic due to a ruptured blood vessel. Another more severely disabled patient, her 47-year-old woman, who the researchers did not identify, had a more common ischemic stroke with occlusion of blood vessels.

The researchers implanted eight electrode strands in two locations corresponding to where neurosensory fibers from the arm and hand enter the spinal cord.

Marco Capogrosso, an assistant professor of neurosurgery at the University of Pittsburgh, says the approach stems from the fact that in the case of a stroke, some nerve areas remain undamaged.

“So if we can build this technology to amplify neural signals, we might have an opportunity to restore arm and hand movement.” Professor of mechanical engineering at the University of Pittsburgh and Carnegie Mellon University Neuroscience Institute. Douglas Weber, who is

For four hours each day, five days a week, researchers enabled the stimulation, adjusted it to determine the optimal parameters for each patient, and asked them to attempt a variety of movements and tasks. Immediately, the effect was noticeable.

“My first day in the lab, and the first time they turned it on, I was sitting in a chair. They asked me to open and close my hands. It was really hard for me. That’s it,” Rendulik said. “I was opening and closing my hands quickly,” she said as her husband and her mother watched. “We all cried.”

Over the course of four weeks, she was given increasingly difficult tasks, such as grabbing and moving soup cans. With stimulation, her left hand moved over the barrier in the box and she moved 14 small blocks, whereas without stimulation she moved 6 blocks.

Lendulik, 33, who works from home in her company’s human resources department, said that when she usually tries to make her left hand hold a pen, it feels like her arm is “made of rock” and disconnects from her brain. is likely to fall. she said. With stimulation, she said, “her brain was able to find her left arm more easily.”

Another patient, whose left hand was almost completely paralyzed, was given simpler tasks but improved in skills such as reaching.

The researchers also tested “sham” stimulation that randomly activated the electrodes to see if patients responded to a sort of placebo effect rather than stimulation specifically targeted to the arm or hand. . Both performed better with targeted stimulation.

Patients felt irritation, but it didn’t cause pain, stiffness, or safety issues, researchers report.

The approved study protocol required removal of the electrodes after 29 days. But one month later, the patient retained improved performance, surprising the researchers. Only he “thought it was impossible” after four weeks of stimulation, Dr. Pirondini said.

Dr. Capogrosso said it’s unclear exactly why this effect persists, but “the same neural processes that enable these people to use this method of stimulation are activated when the stimulation is turned off. will also lead to recovery of movement.” “We’re not making new fibers, but we’re definitely re-enhancing what’s there,” he said.

Some experts noted that the pilot study was not designed to answer the most important question for patients: Can improvements in laboratory performance translate into important skills in everyday life? mosquito?

Dr. Daniel Lu, professor and vice president of neurosurgery at the University of California, Los Angeles, said: 2016 research We showed that spinal cord stimulation from implanted electrodes improved hand strength and control in two spinal cord injury patients.

Dr. Lou believes stimulation is promising, but it is difficult to assess its impact in the new study because there was no comparison group and patients were not given the same regimen of intense activity before stimulation. said it was.

“Is it possible that you could have had the same effect in patients who were just exercising and not stimulating?” he asked.

Another question raised by neuroscientists is whether or under what circumstances it would be better to surgically implant electrodes or place them on the skin, an inexpensive method called transcutaneous stimulation. is. The authors of the new study believe surgical implantation is superior because it is “much more specific” and can “target the muscles that control the wrist and hand.”

Others, like Chet Moritz, a professor of neuroengineering at the University of Washington, report improvements in spinal cord injury patients using electrodes on the skin, including benefits lasting months after stimulation ends. “Sure, we can’t adjust our shoulders to this degree, our elbows to this degree, our wrists to that degree, but our nervous system seems to handle it for us,” he said. rice field.

Some neurology experts predicted that both methods could ultimately be useful and appropriate for different patients, depending on health and other factors. All experts, including the study authors, said stimulation was more effective when combined with rehabilitation therapy.

The study’s authors said their ongoing study is evaluating patients of varying stroke severity, age, and other characteristics to determine who would benefit from their approach. They said they founded the company and envisioned allowing patients to adjust stimulation via an app or remote control, similar to similar technology for chronic pain.

Rendulic would welcome regular stimulation for stroke patients. “I threatened not to show up for surgery to have it removed,” she said.

She’s devised ways to do activities like driving and typing one-handed, but the daily frustration comes down to having her husband, Mark, whom she calls “my left-handed guy,” slice steaks for her. There is.

“In the trial, I was able to cut a steak. It was great,” she said. Then, holding a fork in her left hand, she speared a piece of her and lifted it into her mouth. It’s a move that was previously impossible at one time.