Spinal cord injuries are notoriously difficult to treat. They are even more challenging for patients who have been paralyzed for several years. According to the National Spinal Cord Injury Association, more than 450,000 people in the U.S. alone are living with a spinal cord injury. Thankfully, a team of researchers has developed a new implant that can reverse paralysis in patients with severe spinal cord injuries.
How does it work?
This implant, which was developed by Jocelyne Bloch, a neurosurgeon at Lausanne University Hospital, and Grégoire Courtine, a professor of neuroscience at the Swiss Federal Institute of Technology, employs specifically designed electrodes to reconnect the brain with the paralyzed lower body. The findings of this research have been published in the journal Nature Medicine.
The implant is placed in the spinal cord and attached to the patient’s nerve fibers. Instead of targeting pain receptors, the implant uses electrodes to send personalized signals to the spinal nerves that are responsible for controlling leg and trunk movements. This mimics the action of the brain in sending electrical impulses to the muscles.
Typically, nerves in a healthy spine transmit signals from the brain to the legs. But following a spinal injury, those signals become weak or nonexistent. Legs muscles may be healthy enough to walk, but without the brain signaling them to, they remain immobile.
That’s where the new implant comes in. It helps patients walk again by acting as a signal booster, restoring communication between the brain and the lower body. Artificial intelligent software, which accompanies the implant, triggers electrical impulses.
“Our stimulation algorithms are still based on imitating nature,” Courtine explained in a press statement. “And our new, soft implanted leads are designed to be placed underneath the vertebrae, directly on the spinal cord. They can modulate the neurons regulating specific muscle groups. By controlling these implants, we can activate the spinal cord like the brain would do naturally to have the patient stand, walk, swim or ride a bike, for example.”
Bloch added that the “breakthrough here is the longer, wider implanted leads with electrodes arranged in a way that corresponds exactly to the spinal nerve roots. That gives us precise control over the neurons regulating specific muscles.”
It helped paralyzed men stand, walk, and swim again
Courtine and his team trialed the new implant on three completely paralyzed patients who had been injured in motorcycle accidents. All three patients in the trial had a complete loss of voluntary movement in their lower bodies. Two even had a complete loss of sensation.
After inserting the implants, researchers used a tablet to initiate unique sequences of electrical pulses to activate the participants’ muscles. And within a day, all three patients regained mobility and were able to stand, walk, and even peddle. They were able to walk again and engage in more advanced activities after six months with the implant.
What’s more, because the technology is miniaturized, the patients can perform their training exercises outdoors and not only inside a lab.
“All three patients were able to stand, walk, pedal, swim, and control their torso movements in just a day after their implants were activated,” Courtine said. “That’s thanks to the specific stimulation programs we wrote for each type of activity. Patients can select the desired activity on the tablet, and the corresponding protocols are relayed to the pacemaker in the abdomen.”
More research is needed
There’s still a long way to go before the implant can be rolled out and used routinely to help paralyzed people walk just, according to Courtine.
“This is not a cure for spinal cord injury. But it is a critical step to improve people’s quality of life. We are going to empower people,” he said. “We are going to give patients the ability to stand, to take some steps. It is not enough, but it is a significant improvement.”
Courtine and Bloch plan to work with other researchers to make the implant and its tech more user-friendly for everyday use. That includes integrating it with smartwatches and other devices. Additionally, the team hopes to begin a 50-100 patient clinical trial within a few years and eventually a 1,000-person trial to gain approval from the U.S. Food and Drug Administration (FDA). If approved, the implant could offer new hope for thousands of paralyzed people globally.