BIG STEPS: Hospital studies walking therapy for children with cerebral palsy

By Kathleen Longcore
The Grand Rapids Press

Amy Valderas gets teary just watching her 7-year-old son walk across a room.

"I could watch him for hours, because when he was small they said he might never walk," Valderas said.

Born prematurely at just 26 weeks, Jaime Garcia suffered cerebral palsy -- permanent brain damage that affected his limbs and coordination.

Since then, he has had multiple surgeries and lots of therapy at Ken-o-sha Park Elementary in Grand Rapids. And he's not only walking, he tries to run.

He also is part of a new research study at Mary Free Bed Hospital &Rehabilitation Center which might be able to smooth out his unsteady gait.

Using knowledge gleaned from other studies -- including groundbreaking work at UCLA -- therapists will assess how children with cerebral palsy walk before and after eight weeks of regular therapy and again after eight weeks of a trial therapy called supported treadmill training.

The study uses training similar to that in research presented in Grand Rapids earlier this month by Susan Harkema, an assistant professor of neurology at UCLA and a researcher at the university's Human Locomotion Research Institute.

Harkema and others in her field have exploded long-held theories about how people walk by proving that some people paralyzed from spinal cord injuries can learn how to stand and walk.

The California research, with a team that includes neuroscientists, engineers, computer programmers, and a physical therapist, gets funding from the National Institutes of Health, the National Multiple Sclerosis Society, and the Christopher Reeve Paralysis Foundation.

Harkema's recent presentation at a spinal cord symposium sponsored by Mary Free Bed was a homecoming of sorts -- she is a Jenison High School graduate.

She said for decades, scientists believed people walked because the brain sent messages through the spinal cord to motor nerve cells, which sent signals to the muscles in the legs and feet. Under this theory, if spinal cord injury cut off the message from the brain, the person could no longer walk.

But what animal studies and now human research have shown is that a healthy spinal cord below the area of injury can be trained to remember how to send walking signals.

"In animal research we saw that the spinal cord itself has the capacity to re-learn how to take steps," Harkema said. "So we thought the spinal cord might be able to operate without signals from the brain,"

Her studies have shown that locomotion -- the act of standing and taking steps -- helps the spinal cord send appropriate messages to motor neurons.

The experiments suspend paralyzed patients in a harness above a treadmill. Harkema's team found three things helped the spinal cord remember: near normal weight load on the joints, manually moving the ankles, knees and legs, and setting the treadmill at a normal walking speed.

"You can re-train the spinal cord with appropriate sensory cues from the muscles," Harkema said. "Even though (the paralyzed person) can't perceive it or feel it because of the disconnect to the brain, the spinal cord can still perceive it."

The act of stepping seemed to stimulate the spinal cord, and paralyzed patients who started stepping with manual assistance were soon taking steps on their own.

Even patients who could not voluntarily flex their knees and ankles when they were at rest could flex them -- a movement necessary to walking --when they were stepping on a treadmill. This means voluntary control of the legs does not predict a patient's ability to walk.

Harkema said the research proves the spinal cord is not just a conduit for locomotion signals from the brain.

"The spinal cord takes care of the details of movement," she said. "And, if we can understand how it does that, we can get closer to the silver bullet" -- a cure for paralyzing spinal cord injury.

It remains to be seen whether Harkema's discoveries can be translated to therapies for children like Jaime who have permanent brain damage.

In a previous limited study at Mary Free Bed, nine weeks of supported treadmill training improved children's endurance, heart rate and oxygen intake. But the study was too small to be conclusive, said Lisa Beard, a physical therapist with a master's degree from Grand Valley State University. And the study, which was designed at GVSU, had no control group.

Since then the study has been tweaked, with controls added, said Beard, who did the previous study as part of a pediatric fellowship.

The good results from Harkema's lab in California give Valderas reason to hope her son's gait can be improved. And she jumped at the chance to enroll him in the Mary Free Bed study.

"Jaime makes things easier for me because he's so determined. He's a fighter, and he's come a long way," she said.

Original source: http://www.mlive.com