This Sleeve Can Return Hand Function to People Who Are Paralyzed

Participants were able to grasp a water bottle

The three most terrifying words you can hear if you have a spinal cord injury have got to be, “You have quadriplegia.” The most severe form of paralysis, being quadriplegic means not being able to move your arms or your legs. Your torso, including breathing muscles, may be paralyzed as well.

You may feel hopeless if you’ve been diagnosed with quadriplegia, but you have more reason to hope than ever before. From stem cells to neuromuscular stimulators, researchers are working on promising treatments to help patients get some measure of function back.

SCI wearable sleeveA team at Northwell Health has developed a sleeve to help people with quadriplegia regain hand function

One of these treatments is an innovative wearable sleeve that one study has shown can help people with quadriplegia regain some hand function. The technology is known as neural bypass, because it bypasses the spinal cord and other elements of a damaged nervous system and connects the brain directly to muscles.

“Regaining hand function is one of the biggest unmet clinical needs,” says Chad Bouton, vice president of advanced engineering at the Feinstein Institutes for Medical Research at Northwell Health and lead author of a study detailing the sleeve.

The data backs Bouton up. A 2004 study in Journal of Neurotrauma found that regaining arm and hand function was the top priority for people with quadriplegia.

Nerves and Muscles

Central nervous systemSpinal cord injuries interrupt communication between the brain and the muscles.

Here’s how movement works in a healthy nervous system.

  • First, you think about the movement you want to make. This generates a tiny electrical charge in an area of the brain called the primary motor cortex.
  • Next, in a split second this signal gets passed down to the spinal cord.
  • The spinal cord sends the signal down one of the peripheral nerves toward the area that needs to be moved.
  • The peripheral nerve tells the muscles to contract, making the movement happen.

For people who have had spinal cord injuries, the process gets interrupted. The spinal cord can’t pass the signal on to the peripheral nerves, so when the patient thinks of a movement, nothing happens. The result is paralysis: usually paraplegia (paralysis of the legs) in someone who’s had a spinal cord injury in the low- or mid-back area, and quadriplegia (paralysis from the neck down) after a neck injury.

Wearable Nerves

A study, written by Bouton and colleagues and published in Bioelectric Medicine in November 2019, details early efforts of Bouton’s team to build a wearable sleeve to help the muscles of quadriplegics contract. Affectionately known by the team as “The Sleeve,” the device acts as a sort of wearable nerve that can stimulate the forearm muscles to contract, making the hand grip and release.

Neural bypass sleeveThis neural bypass sleeve acts as wearable nerves for people with paralysis. Credit: The Feinstein Institutes for Medical Research

The sleeve detailed in the study is a noninvasive medical device. Using proprietary software and artificial intelligence algorithms, it allows for contractions of large muscles to perform basic movements. Bouton was tight-lipped about how exactly the sleeve works, but says, “After collecting years of data, we’re able to figure out when someone wants to do some basic things like opening or closing hand. They won’t be playing Guitar Hero—moving individual fingers—but they can perform basic movements. It’s a really great breakthrough.”

The Future of Spinal Cord Injury Treatment

Although the technology outlined in the study is still in its infancy, Bouton and his team have more advanced applications in the works. Two of them require the implantation of a tiny computer chip in the brain, but will allow the patient to make fine motor movements and even regain their senses of touch.

The first form of technology is an amplification of the sleeve discussed in the study. The computer chip goes into the movement center of the patient’s brain and amplifies that tiny electrical signals that give rise to thoughts, feelings and actions. The chip then sends those amplified signals to the sleeve

“I’ve worked with patients who are seven years post-injury, and in all cases we’re finding activity in the motor area of the brain is quite high,” says Bouton. “That’s good news.” Activity in the primary motor cortex is what allows the computer chip to act as the spinal cord and peripheral nerve, passing the impulse to the sleeve, which contracts the right muscles.

Brain activityThe brain's movement centers stay active long after spinal cord injuries.

That’s a one-way street, from the brain to the muscles. “We’re also working on two-way,” says Bouton. A two-way connection would not only allow the patient to move his or hand by sending signals from the brain to the sleeve, it would return their sense of touch by transmitting stimuli from the sleeve back to the brain via another chip implanted in the sensory area of the brain.

“One of the very first study participants said he can see his hand moving but can’t feel the object,” notes Bouton. “We decided to launch a new effort to restore the sense of touch.”

The Way Forward

To further develop these advanced neural bypass treatments, Bouton and his team are currently recruiting for two new clinical trials. The first, “Evaluating Neuromuscular Stimulation for Restoring Hand Movements” is similar to the study written about in Bioelectric Medicine, testing out a noninvasive neurostimulating sleeve.

The second, however, involves the use of a chip in the brain. Called “Restoring Motor and Sensory Hand Function in Tetraplegia Using a Neural Bypass System,” this study will attempt to test the two-way neural bypass both to give participants the use of their hands and to return sensation.

Bouton acknowledges that the devices won’t be market-ready for years—two to three for the noninvasive model and up to a decade for the chip-based device. But that doesn’t discourage study participants, he says.

“We often ask participants why they got involved with our studies. They say they understand it will take a number of years to develop this technology and make it available,” he says. “They understand it’s all research, but they say they want to be able to help others in the future. I think it’s a very selfless act, really noble to do that.”

Need more info on spinal cord injuries? Head to our SCI hub to learn about treatments that can help right now.

Updated on: 03/20/20
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