High-tech implant helps paralyzed man walk more naturally

by Dennis Thompson

HealthDay Reporter

WEDNESDAY, May 24, 2023 (HealthDay News) — A Dutch man with paralyzed legs can now stand and walk, thanks to a wireless interface between his brain and spinal cord that responds to his thoughts by moving his legs.

Gert-Jan Oskam, 40, suffered a spinal cord injury 11 years ago due to a bicycle accident in China that left him unable to walk.

Oskam now has a brain implant that picks up movement signals that, in a healthy person, would travel down the spinal cord and cause the legs to move. Instead, that implant transmits those signals wirelessly to a second implant located in the lower part of the spine, which then stimulates the leg muscles into action, the researchers report.

This experimental high-tech “digital bridge” between the brain and the spinal cord allowed Oskam to pick up a paintbrush the other day and perform a simple, low-tech task at home in the Netherlands.

“There was something to paint and there was no one to help me, so I had to walk and paint,” Oskam said at a news conference on Tuesday. “I did it myself, while standing up.”

For years, researchers have been trying to restore the ability to walk using nerve stimulators implanted in patients’ spinal cords.

However, those test subjects often walked robotically and were unable to adapt their leg movements to different terrain.

Oskam has benefited from the next step in that research, a way to allow the brain to control spinal stimulation and create a more natural gait for patients.

“What we have been able to do here is restore communication between the brain and the region of the spinal cord that controls leg movement with a digital bridge that picks up Gert-Jan’s thoughts and translates these thoughts into spinal cord stimulation. . to restore voluntary movement of the legs,” said lead researcher Gregory Courtineneuroscientist and professor at the École Polytechnique Fédérale de Lausanne, in France.

Oskam says she can now walk 100 to 200 meters (up to about 660 feet) at a time and can stand hands-free for two to three minutes.

The device has also improved Oskam’s neurological recovery. He has been able to walk on crutches even with the implant disconnected.

more natural movement

Oskam already had a spinal stimulator implanted in his back, due to his involvement in previous studies. That allowed her to move, but his movements were robotic and stiff.

“It wasn’t completely natural. Before, the stimulation controlled me, and now I control the stimulation with my thoughts,” explained Oskam.

The researchers developed a passive implant located over the motor center of his brain that could pick up signals that would normally control movement.

Using a special headset and walker, Oskam is able to take more natural steps as the brain implant picks up movement signals and then transmits them to the spinal stimulator.

“We were able to calibrate the first models in a few minutes, which allowed Gert-Jan to control the flexion of her hips. And after several minutes of training, she was able to walk naturally using the system,” said lead researcher Henri Lorach, a professor at the École Polytechnique Fédérale de Lausanne.

“When the brain controls the stimulation, there is even more recovery because it is a convergence of the digital connection with the natural connection in the same type of neurons,” Courtine explained.

more research is needed

The new study was published May 24 in the journal Nature.

The research team hopes to recruit a second patient with lower body paralysis to receive the brain implant, to see if the same system will work in others.

Marco Baptista, chief scientific officer at the Reeve Foundation, agreed that the technology needs to be tested in more people.

“It needs to be extended and investigated in other people who have different types of injuries,” Baptista said.

At the same time, Baptista noted that the effort represents the “next generation” of research on restoring movement through spinal stimulation.

“They are moving more and more towards making the whole process more natural, where thought and will control the stimulation,” Baptista said.

The researchers are also starting another clinical trial that will help people with paralysis in the upper body.

“In fact, we are investigating how we can use the same principle to restore upper extremity function by targeting the cervical spinal cord with similar technology,” Lorach said. “We can decode what the intention is to move the arm and hand and stimulate the motor pulse that will trigger this activity.”

They also want to further miniaturize the technology, making it easier for people to participate in daily activities without having to wear a hat or carry equipment, Courtine said.

“We could even apply it to other pathologies such as stroke, where cortical activity can also be recorded and linked to stimulation of the spinal cord to move a limb,” said co-investigator Dr. Jocelyne Bloch, a neurosurgeon at the Hospital Lausanne University. “You’d think there are many different applications of this pioneering novel therapy.”

More information

The University of California, San Diego has more about spinal cord injury and paralysis.

SOURCES: Gert-Jan Oskam, 40, Netherlands; Gregoire Courtine, PhD, neuroscientist and professor, École Polytechnique Fédérale de Lausanne, France; Henri Lorach, PhD, professor, École Polytechnique Fédérale de Lausanne, France; Marco Baptista, PhD, scientific director, Reeve Foundation, Short Hills, NJ; Jocelyne Bloch, MD, neurosurgeon, Lausanne University Hospital, France; NatureMay 24, 2023