Micro implants could restore standing and walking

December 3, 2019

University of Alberta Faculty of Medicine & Dentistry

Researchers are focused on restoring lower-body function after severe spinal injuries using a tiny spinal implant. In new research, the team showcases a map to identify which parts of the spinal cord trigger the hip, knees, ankles and toes, and the areas that put movements together.

When Vivian Mushahwar first applied to grad school, she wrote about her idea to fix paralysis by rewiring the spinal cord.

It was only after she was accepted into a bioengineering program that the young electrical engineer learned her idea had actually prompted laughter.

"I figured, hey I can fix it, it's just wires," Mushahwar said. "Yeah, well, it's not just wires. So I had to learn the biology along the way."

It's taken Mushahwar a lot of work over two decades at the University of Alberta, but the Canada Research Chair in Functional Restoration is still fixated on the dream of helping people walk again. And thanks to an electrical spinal implant pioneered in her laboratory and work in mapping the spinal cord, that dream could become a reality in the next decade.

Because an injured spinal cord dies back, it's not simply a matter of reconnecting a cable. Three herculean feats are needed. You have to translate brain signals. You have to figure out and control the spinal cord. And you have got to get the two sides talking again.

People tend to think the brain does all the thinking, but Mushahwar says the spinal cord has built-in intelligence. A complex chain of motor and sensory networks regulate everything from breathing to bowels, while the brain stem's contribution is basically "go!" and "faster!" Your spinal cord isn't just moving muscles, it's giving you your natural gait.

Other researchers have tried different avenues to restore movement. By sending electrical impulses into leg muscles, it's possible to get people standing or walking again. But the effect is strictly mechanical and not particularly effective. Mushahwar's research has focused on restoring lower-body function after severe injuries using a tiny spinal implant. Hair-like electrical wires plunge deep into the spinal grey matter, sending electrical signals to trigger the networks that already know how to do the hard work.

In a new paper in Scientific Reports, the team showcases a map to identify which parts of the spinal cord trigger the hip, knees, ankles and toes, and the areas that put movements together. The work has shown that the spinal maps have been remarkably consistent across the animal spectrum, but further work is required before moving to human trials.

The implications of moving to a human clinical setting would be massive, but must follow further work that needs to be done in animals. Being able to control standing and walking would improve bone health, improve bowel and bladder function, and reduce pressure ulcers. It could help treat cardiovascular disease -- the main cause of death for spinal cord patients -- while bolstering mental health and quality of life. For those with less severe spinal injuries, an implant could be therapeutic, removing the need for months of gruelling physical therapy regimes that have limited success.

"We think that intraspinal stimulation itself will get people to start walking longer and longer, and maybe even faster," said Mushahwar. "That in itself becomes their therapy."

Progress can move at a remarkable pace, yet it's often maddeningly slow.

"There's been an explosion of knowledge in neuroscience over the last 20 years," Mushahwar said. "We're at the edge of merging the human and the machine."

Given the nature of incremental funding and research, a realistic timeline for this type of progress might be close to a decade.

Mushahwar is the director of the SMART Network, a collaboration of more than 100 U of A scientists and learners who intentionally break disciplinary silos to think of unique ways to tackle neural injuries and diseases. That has meant working with researchers like neuroscientist Kathryn Todd and biochemist Matthew Churchward, both in the psychiatry department, to create three-dimensional cell cultures that simulate the testing of electrodes.

Learn about he remarkable brain and the central nervous system. Click here.

The next steps are fine-tuning the hardware -- miniaturizing an implantable stimulator -- and securing Health Canada and FDA approvals for clinical trials. Previous research has tackled the problem of translating brain signals and intent into commands to the intraspinal implant; however, the first generation of the intraspinal implants will require a patient to control walking and movement. Future implants could include a connection to the brain.

It's the same goal Mushahwar had decades ago. Except now it's no longer a laughable idea.

"Imagine the future," Mushahwar said. "A person just thinks and commands are transmitted to the spinal cord. People stand up and walk. This is the dream."

Wednesday, December 6, 2017

Steeler's football injury: Protecting the miraculous, fragile spinal cord

Source: USA Today

As Ryan Shazier continues to undergo tests at the University of Cincinnati Medical Center for a spine injury, he tweeted a thank-you Tuesday evening.

Shazier was injured during the Pittsburgh Steelers' win over the Cincinnati Bengals onMonday Night Football. He was taken by ambulance to the hospital after being removed from the field on a backboard.

"Thank you for the prayers. Your support is uplifting to me and my family. #SHALIEVE"

Earlier Tuesday, team general manager Kevin Colbert said Shazier is not expected to need surgery. Doctors released a statement that said he will remain hospitalized for more tests and evaluations during the next 24-48 hours.

Shazier underwent a CT scan and MRI after being injured in the first quarter of the Steelers' 23-20 win.

After he tackled receiver Josh Malone with the crown of his helmet, he slumped to the turf and his body went limp. He later grabbed his middle back and it appeared he was having trouble moving his legs.

Learn about the brain, the spinal cord and the central nervous system in easy-to-read form.

Source: National Institute of Neurological Disorders and Stroke:

How does the spinal cord work? To understand what can happen as the result of a spinal cord injury, it is important to understand the anatomy of the spinal cord and its normal functions. The spinal cord is a tight bundle of neural cells (neurons and glia) and nerve pathways (axons) that extend from the base of the brain to the lower back. It is the primary information highway that receives sensory information from the skin, joints, internal organs, and muscles of the trunk, arms, and legs, which is then relayed upward to the brain. It also carries messages downward from the brain to other body systems.

Millions of nerve cells situated in the spinal cord itself also coordinate complex patterns of movements such as rhythmic breathing and walking. Together, the spinal cord and brain make up the central nervous system (CNS), which controls most functions of the body. The spinal cord is made up of neurons, glia, and blood vessels. The neurons and their dendrites (branching projections that receive input from axons of other neurons) reside in an H-shaped or butterfly-shaped region called gray matter. The gray matter of the cord contains lower motor neurons, which branch out from the cord to muscles, internal organs, and tissue in other parts of the body and transmit information commands to start and stop muscle movement that is under voluntary control.

Upper motor neurons are located in the brain and send their long processes (axons) to the spinal cord neurons. Other types of nerve cells found in dense clumps of cells that sit just outside the spinal cord (called sensory ganglia) relay information such as temperature, touch, pain, vibration, and joint position back to the brain. The axons carry signals up and down the spinal cord and to the rest of the body. Thousands of axons are bundled into pairs of spinal nerves that link the spinal cord to the muscles and the rest of the body. The function of these nerves reflects their location along the spinal cord. 4 • Cervical spinal nerves (C1 to C8) emerge from the spinal cord in the neck and control signals to the back of the head, the neck and shoulders, the arms and hands, and the diaphragm. • Thoracic spinal nerves (T1 to T12) emerge from the spinal cord in the upper mid-back and control signals to the chest muscles, some muscles of the back, and many organ systems, including parts of the abdomen.

Lumbar spinal nerves (L1 to L5) emerge from the spinal cord in the low back and control signals to the lower parts of the abdomen and the back, the buttocks, some parts of the external genital organs, and parts of the leg. Between the vertebrae of the spinal column are discs that act as passages through which the spinal nerves travel. These places are particularly vulnerable to injury