Advance offers hope in search for paralysis cure

In a major step forward in research on spinal cord injuries, scientists in Miami will report today that an innovative combination of treatments allowed paralyzed rats to regain up to 70 percent of their ability to walk.

The research is a “significant advance” that may help many of the 243,000 Americans with spinal cord injuries get out of their wheelchairs someday.

Researchers at the Miami Project to Cure Paralysis say they have found a way to promote the growth of nerve fibers in damaged spinal cords and prevent post-injury nerve death. A spinal cord injury damages the nerve circuits that carry messages from the brain to the body.

Recent research has focused on transplanting cells from peripheral nerves outside the brain and spinal cord into the damaged area as a bridge across the injury.

But new nerve fibers didn’t go beyond the bridge due to problems including growth-inhibiting molecules, says researcher Mary Bartlett Bunge.

The first step in the new strategy is to inject the rats with rolipram, a drug that stops the loss of a growth-enhancing chemical called cyclic AMP that occurs after a spinal cord injury. Then researchers take cells from the rats’ peripheral nerves, grow these in the lab and transplant them into the injured area followed by injections of cyclic AMP above and below the transplant site. The injections raise the levels of cyclic AMP, enhancing the environment for growth of nerve fibers, Bunge says.

Naomi Kleitman, of the National Institute of Neurological Disorders and Stroke, says the strategy is a “significant advance over what has been reported before” and is “likely to be applicable clinically if the progress continues.”

The animals went from being able to take only occasional steps to walking in a coordinated way with hind and forepaws working together, Kleitman says. “That’s a much bigger effect” than has been previously seen, she says.

The study will be repeated in animals before moving into tests on people, possibly within a year, says Scott Roy of the Miami Project.