Science Making Strides in Treating Spinal Cord Injuries

Not so long ago, a spinal cord injury meant life in a wheelchair with little chance for improvement. But today, scientists say research is pointing toward treatments that may restore movement, relieve pain and offer hope.

Just ask Diane Hughes. The Hammond, La., teacher was partially paralyzed from the chest down 12 years ago by a gunshot wound and spent the following year having “a pity party,” she says.

She decided that wasn’t helping so with the support of family and faith, she went back to work, built a wheelchair-accessible home and two years ago took part in a study to test new rehabilitation methods at the Miami Project to Cure Paralysis at the University of Miami.

Hughes, 58, was strapped into a computer-driven robot that helped move her legs on a treadmill. After 12 weeks, she says, “I could move my legs easier, lift them easier.” With stronger legs, she found it possible to stand or get in and out of her wheelchair more easily.

The concept behind the research, which is evaluating several methods of locomotion training, says study director Edelle Field-Fote, is that inside the spinal cord is a “mini-brain” doing complex movements innately. “Walking, swimming and flying are things animals do innately,” she says. Humans have evolved in a way that requires the brain to turn those circuits on, but by retraining the circuits in the spinal cord, it might be possible to enhance motion, even when signals from the brain are blocked.

More than 200,000 people in the United States use wheelchairs because of a spinal cord injury, and every year about 11,000 more injuries occur, slightly more than half in people ages 16 to 30.

Research is moving in several directions as scientists find ways to prevent biological processes that cause harm and encourage those that may restore damaged nerve cells. The studies are producing insights into what causes paralysis.

“In the last five years, it has never been more exciting in terms of the knowledge we’re obtaining,” says neurosurgeon W. Dalton Dietrich, scientific director of the Miami Project.

Advancements could lead to new treatments to prevent or reverse severe paralysis.

Complex nerve system

The 2-foot-long cord that runs from the base of the skull to the lower back is made up of a complex highway of nerves that are encased in protective membranes, cushioned by fluid and surrounded by the vertebrae that make up the backbone.

Damage to the spinal cord nerves can result in partial or complete paralysis below the point of the injury. The degree of damage depends on the severity of the injury and where it occurs. An injury high on the spinal cord can leave a person unable to breathe or move his arms and legs without assistance while injuries lower on the back may affect only the legs.

In the hours following an injury, the focus is on stabilizing the spinal cord and preventing nerve death, Dietrich says. Scientists are trying to develop drugs that can be given to patients as soon as possible after the injury to halt the inflammatory process, which can cause further nerve damage.

A major area of scientific discovery is in repair or regeneration of damaged nerve cells, a process once thought impossible. “In medical and graduate school we are taught to think that after injury to the central nervous system there is no recovery,” says Yale neurologist Stephen Waxman.

But research is turning that truism around. At the Kentucky Spinal Cord Injury Research Center at the University of Louisville, scientists are studying the mechanics of cell death, regeneration and new imaging methods to help doctors make surgical decisions.

“What is becoming exceedingly clear is that there’s no one approach that’s going to be successful,” says scientific director Scott Whittemore.

Fixing the pain

At Yale, Waxman and colleagues are identifying what happens to nerve cells to cause the intense pain experienced by up to half of spinal cord injury victims. They have zeroed in on a molecule that may provide a target for drug therapy and other strategies.

Waxman’s team also is focusing on restoring nerve fibers by replacing their protective coating, called the myelin sheath, which helps to speed nerve impulses.

“All spinal cord researchers agree that it looks like you need only 10% to 15% of the nerve fibers … to have some degree of usable gait,” he says. “Now, you’re not going to be doing a ballet dance, but you tell that to Christopher Reeve. If he could walk 15 feet, that would be a major advance in terms of his quality of life.”

Progress will come in increments. “Can we take someone paralyzed from the neck down and give them use of their shoulders? Can we get someone to walk four or five steps? I think those have turned into realistic objectives.”

People with spinal cord injuries should not give up hope

“When I was a kid, I wanted to be an astronomer, and I asked my dad if men could ever walk on the moon,” Waxman says. “He said, ‘That’s impossible.’ Years later, I remember being a med student and with my wife watching men walk on the moon.

“The impossible is now possible. It may not happen overnight, but we now have the tools.”

By: Anita Manning, USA Today

Posted on August 16th, 2004 in Research for a Cure.