Researchers have identified nerve cells essential for helping paralyzed people regain their ability to walk, making this a breakthrough in treating spinal cord injuries.
Nine patients who participated in an ongoing Swiss study to help paralyzed people regain movement contributed to the findings.
With implants that electrically stimulate spinal nerves that control lower-body movement, all nine individuals quickly regained their ability to stand and walk.
According to the latest research, a particular group of cells in the lower spine appear to be required for that movement recovery.
According to experts, it is hoped that the discovery will contribute to improving electrical stimulation therapy and, eventually, aid in developing even more advanced methods to help paralyzed individuals regain complex movement.
According to the American Association of Neurological Surgeons, as many as 450,000 people in the United States are coping with a spinal cord injury. Younger than 30-year-old males make up most of those injured, and traffic accidents or acts of violence are frequently to blame.
The communication between the brain and the spinal nerves below the level of the injury is essentially cut off by spinal cord injuries.
But those nerve cells aren’t dead; they’re just inactive. And for many years, scientists have been researching epidural electrical stimulation (EES) to stimulate those neurons and give paralyzed individuals some degree of movement.
Electrodes that deliver electrical currents to the spinal cord’s neurons are implanted during EES. An implanted pulse generator is connected to the electrodes in the abdomen.
According to Eiman Azim, a researcher at the Salk Institute in La Jolla, California, who examines the mechanisms underlying human movement, EES has been used as a pain treatment for 50 years.
Researchers later discovered that EES also has an impact on movement. Over the past ten years, various research teams have used EES and rigorous physical therapy to aid many paralyzed patients in regaining some degree of standing and walking ability.
Azim claimed that the Swiss team has been “making big leaps” in the direction of the strategy recently.
For instance, they have created electrodes that target the spinal cord’s “dorsal root” regions, which regulate trunk and leg movement. Additionally, they have incorporated sophisticated technology that stimulates nerves in a way that more closely resembles how the brain would carry out the task.
The team, which includes members from the University of Lausanne and the Swiss Federal Institute of Technology, reported on their three most recent patients earlier this year. The patients, all men between the ages of 29 and 41, had spinal cord injuries that prevented them from feeling or moving their legs.
In 2020, surgery was performed on everyone to implant the EES hardware. The implants were used in conjunction with software that enables patients and physical therapists to create semi-automated stimulation programs that allow a range of movements. Users can run these programs independently using a tablet and tiny remote controls that wirelessly connect to the pulse generator.
After recovering from surgery, those three patients could stand and walk with assistance right away.
Along the way, the Swiss team made an intriguing discovery: Some of their nine patients were still able to walk when the electrical stimulation was turned off, which, according to Azim, suggests that the neurons involved in walking have undergone a “reorganisation.”
To learn more, the researchers used lab mice to mimic many of the critical aspects of EES in people who have suffered spinal cord injuries. They could focus on a group of Vsx2 neurons that they believe to be “essential” for restoring walking in EES patients.
When lab mice were given EES, “silencing” the neurons prevented them from regaining their ability to walk; activating them allowed them to move again.
What occurs in the spinal cord during stimulation was the focus of this study, according to Azim. That is a sizable black box.
The regained function in these nine patients was praised as “fantastic” by Dr. Greg Nemunaitis, director of spinal cord injury rehabilitation at the Cleveland Clinic in Ohio.
In addition, he added that until a “cure” is found, the discovery of “recovery-organizing neurons” in mice is “a first step in understanding and enhancing function in humans.”
Soon, according to Azim, the research on these crucial neurons might aid in improving EES.
In the future, he suggested, a better comprehension of how EES promotes movement recovery could aid in creating even more advanced treatments. According to Azim, technology is progressing to the point where it may eventually be safe to access the spinal cord and “rebuild” damaged circuits.
It’s not just a fantasy, he insisted.
