An implant allows a paraplegic to walk and repair his nerve connections

2023-05-24 17:03:39

Gert-Jan is 40 years old. In 2011 he suffered a traffic accident when he was cycling home from his work. After 50 therapy sessions he was unable to lift his legs when he tried to walk or when he was lying on his back. “The doctors told me that he would never be able to walk again,” he says. But now, thanks to a system that restores communication between the brain and spinal cord Through a wireless digital implant, he has been able to walk naturally again with crutches, even when the implant was turned off, by recovering neurological functions that he had lost since his accident.

Gert-Jan is the only person to have participated in a clinical trial that is published in «Nature» and that it establishes a framework for restoring natural control of movement after paralysis and that it seems to repair the connection of the spinal cord because it seems to generate new nerve connections

“We have created a wireless interface -connection- between the brain and the spinal cord using Brain-Computer Interface (BCI) technology that transforms thought into action”, summarizes Grégoire Courtine, Professor of Neuroscience at Federal Polytechnic School of Lausanne (EPFL)he Vaud University Hospital Center (CHUV)and the University of Lausanne (Switzerland).

Thanks to this digital connection, Gert-Jan has been able to regain natural control over the movement of her paralyzed legs, allowing her to stand up, walk and even climb stairs.

A spinal cord injury can destroy communication between the brain and the region of the spinal cord that controls walking, leading to paralysis. Some earlier approaches to restoring movement in people with this type of paralysis involved electrical stimulation of regions of the spinal cord to allow standing and walking.

So this group of EFPL had already developed a system that enabled three patients with complete spinal cord injury to stand, walk, and even engage in recreational activities such as swimming, bicycling, or canoeing, through personalized electrical stimulation of the spinal cord using electrode plates specifically designed for spinal cord injuries. The study was published in «Nature Medicine».

However, this required the use of motion sensors, and patients showed limited ability to adapt leg movements to different terrain and demands. Digitally connecting the brain and spinal cordl could improve control over the timing and range of muscle activity and restore more natural and adaptive control of standing and walking in these patients.

To establish this digital connection, two types of electronic implants are needed. Explains neurosurgeon Jocelyne Bloch, professor in CHUV, UNIL y EPFL, that “WIMAGINE devices have been implanted over the region of the brain that is responsible for controlling leg movements.” These developed devices allow decoding the electrical signals generated by the brain when we think about walking.

In addition, he adds, “we place a neurostimulator connected to an electrode array over the region of the spinal cord that controls leg movement.”

And thanks to algorithms based on adaptive methods of artificial intelligence, explains Guillaume Charvet, «movement intentions are decoded in real time from brain recordings.

These intentions are later converted into sequences of electrical stimulation of the spinal cord, which in turn activate the leg muscles to achieve the desired movement. “This digital bridge works wirelessly, allowing the patient to move independently,” adds Charvet.

The rehabilitation supported by the digital connection allowed Gert-Jan to recover neurological functions that she had lost since her accident.

Thus, the study has been able to quantify notable improvements in their sensory perceptions and motor skills, even when the digital connection was turned off.

This digital bridge could also be applied to other clinical indications, such as paralysis due to stroke.

According to the researchers, this digital repair of the spinal cord suggests that new nerve connections have developed.

Although, Bloch and Courtine note, it has only been tested in one person, they believe a similar strategy could be used in the future to restore arm and hand function.

And, such a digital bridge could also be applied to other clinical indications, such as paralysis due to stroke.

Gert-Jan now has a control natural on the patient’s leg movements to stand up, walk, climb stairs and even traverse complex terrain, even when the connection was turned off.

Gert-Jan sums it up as having rediscovered the pleasure of being able to share a beer standing in a bar with friends: “This simple pleasure represents a significant change in my life.”