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SALT LAKE CITY — A man in France who watched his mobility decline for three decades due to Parkinson's disease has new pep in his step thanks to an experimental spinal cord implant that stimulates the nerves to help him walk more stably.
The neuroprosthesis was the result of work by researchers in France, Switzerland and elsewhere, who mapped the lower spinal cord. The device was developed and implanted by a team from Switzerland.
Marc Gauthier, 63, who lives near Bordeaux, France, has been living with the implant for about two years now, some of that time in rehabilitation learning to walk with its help.
As CNN reported, "Marc Gauthier can now step into an elevator without his body stiffening and freezing in place. He can take a 3-mile lakeside stroll without stopping. He can stand up out of a chair with ease."
Gauthier told news reporters that his gait would often freeze up. "And now, it just doesn't happen anymore. I don't have freezing anymore," he told reporters, in French that was translated into English.
His experimental surgical journey was published in the journal Nature Medicine. The article says those with late-stage Parkinson's disease often have debilitating motor-control issues that are "resistant to currently available therapies."
The National Institute on Aging describes Parkinson's disease as a "brain disorder that causes unintended or uncontrollable movements, such as shaking, stiffness and difficulty with balance and coordination." It says that "symptoms usually begin gradually and worsen over time. As the disease progresses, people may have difficulty walking and talking. They may also have mental and behavioral changes, sleep problems, depression, memory difficulties and fatigue."
Stimulating leg movement
For the experiment, the researchers created a neuroprosthesis that stimulates the parts of the spinal cord that are crucial to walking. Before they placed it in Gauthier, the article noted his severe gait impairments and said that he fell often. That's no longer true, post-implantation.
In the study, the researchers wrote that the implant "interacted synergistically with deep brain stimulation" in ways that promote longer steps, improve balance and stop his gait from freezing.
CNN quoted a member of the research team, from Lausanne University Hospital in Switzerland, who spoke during the news conference. "Addressing deficits of gait and balance in Parkinson's disease is extremely challenging. These deficits can be very heterogeneous. They can be variable across patients. They can affect walking but also symmetry, balance, posture," said Dr. Eduardo Moraud, one of the study authors.
"The neuroprosthetic approach that we have developed here allows for the first time to target and address these problems individually in a highly specific manner for each patient," Moraud said. "It operates in real-time, and importantly, it is complementary to other existing therapies."
Gauthier had previously been treated with dopamine replacement therapy and in 2004 he had deep brain stimulation. But he had developed severe walking disorders. He told reporters he fell about four times a day, which ended his career as an architect.
CNN reported that he uses the device now for about eight hours daily, turning it off if he sits for long periods of time or is sleeping.
The implant does not stem the progress of the debilitating disease, but it does provide higher quality of life, the researchers told reporters.
Studying the device
MIT Technology Review reported the team first tested the device on three monkeys who had balance and walking challenges similar to those that people with Parkinson's may experience. "They implanted the devices into the monkeys' spinal cords and also gave each monkey a brain-computer interface that allowed researchers to tell when the monkey wanted to walk. Then the researchers delivered short bursts of electrical signals through the spinal implant, ultimately restoring walking abilities in all three monkeys."
Gauthier's implant includes electrodes on top of his spinal cord that are connected to a neurostimulator under the skin in his abdomen. When he wants to take a walk, he pushes a button on a remote control to activate the neurostimulator with electrical signals to the spinal cord.
A second patient has started the process of getting the implant, and six others are planned as part of a clinical trial, the work supported in part by a $1 million donation from the Michael J. Fox Foundation. A commercial version is also being developed, CNN reported.
Researchers don't know if the device will work for all Parkinson's patients with gait issues.
The Guardian quoted Grégoire Courtine, a neuroscientist at École Polytechnique Fédérale de Lausanne, who co-led the work. "At this stage, it's a proof of concept," he said. "Of course it's not tomorrow, it will be at least five years of development and testing."
