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Summer 2005 Vol. 5 No. 2



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©Rick Smith/Images.com Regenerating Hope


Speeding Progress Toward Cures for Spinal Cord Injuries

The ancient Egyptians considered spinal cord injury a condition that could not be treated, and even after doctors began to try -- the Greek physician Hippocrates was one of the first -- their attempts met with little success. Until around World War II, the vast majority of people who sustained these injuries died within a year, often from infections that followed on the heels of the trauma.









The arrival of antibiotics and other improvements in care made survival possible for many with spinal cord injuries. But doctors and researchers had written off the idea of curing the fundamental injury and the paralysis and loss of sensation it caused. Once spinal cord neurons were destroyed, it was believed, they were gone for good.

Fortunately, research in recent years has undercut that assumption. Studies have shown that nerve cells and their axons -- the threadlike fibers that conduct electrical impulses to other cells -- can indeed be regenerated, a finding that creates new possibilities for treating spinal cord injuries. And the attention drawn to these opportunities by the late actor Christopher Reeve following his own injury has given new vigor to the research effort.

"We now need to think about a new stage in recovery -- actual improvement of the injured cord," said Richard T. Johnson, a professor of neurology, microbiology, and neuroscience at the Johns Hopkins University School of Medicine in Baltimore. Johnson chaired an Institute of Medicine committee that recently looked at the status of research on spinal cord injuries and suggested ways to accelerate progress toward new treatments.

When most people think of a "cure," they think of restoring the ability to walk again, but the committee's report urges a broader approach. Research should be directed not only at restoring major motor functions such as walking, but also at healing the other body systems damaged by these injuries -- sensory, bladder, and sexual functions, for example. Better treatments are also needed for complications such as pain, spasticity, pressure sores, and depression.

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Few therapies are ready for clinical trials, the report says, but many show promise in cell cultures and animal studies. If transplanted, cells that usually protect axons in other parts of the body may be able to stimulate, guide, and protect axons in the spinal cord as well. And though research is still in its early stages, stem cells from adult and embryonic tissues show strong potential for replacing damaged spinal cord cells. One innovative approach may use engineered tissues to fill gaps in the injured cord, and to serve as "scaffolds" from which transplanted cells could grow.

Regenerating nerves is only one part of restoring function, however. Another research priority is finding ways to steer the growth of axons so that they connect with and stimulate the right cells and tissues. If they connect in the wrong way, then pain and spasticity -- rather than recovery of movement and other functions -- can result.

Research should also be devoted to developing acute-care therapies that could be used soon after an injury, the report adds. A cascade of inflammation, cell death, and scarring occurs in the days and weeks after the trauma, and finding ways to block these processes could help minimize damage.

No single treatment will likely cure these injuries, the committee cautioned. Researchers should focus on finding combinations of therapies that could work together. For example, therapies that promote the growth of axons could be developed alongside agents that produce myelin, the substance that protects axons and speeds nerve impulses.

Coordinating all of the research activities -- and translating promising findings into treatments quickly -- will require a centralized network, the report says. The National Institutes of Health should establish a Spinal Cord Injury Network to lead and organize future research efforts.   -- Sara Frueh


Spinal Cord Injury: Progress, Promise, and Priorities. Committee on Spinal Cord Injury, Board on Neuroscience and Behavioral Health, Institute of Medicine (2005, 352 pp.; ISBN 0-309-09585-9; available from the National Academies Press, tel. 1-800-624-6242; $49.95 plus $4.50 shipping for single copies).

Richard T. Johnson, Distinguished Service Professor of Neurology, Microbiology, and Neuroscience, Johns Hopkins University School of Medicine and Bloomberg School of Public Health, Baltimore, chaired the committee. The study was funded by the State of New York Department of Health.



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Copyright 2005 by the National Academy of Sciences