Combo Therapy May Reverse Paralysis
Study Suggests Walking Can Be Restored Without Regrowing Damaged Nerves
Sept. 21, 2009 -- Researchers at UCLA have taken steps toward restoring the ability to walk after a spinal cord injury that results in paralysis.
Gregoire Courtine and colleagues say a complex combination of drugs, exercise, and electrical stimulation remodels nerve circuits in the spine of paralyzed rats, allowing them to take weight-bearing steps and even run on a treadmill.
The trio-treatment regimen involves injecting medication called serotonin agonists and applying electric currents to the spinal cord below the point of injury while the animals were on a slow-moving treadmill. Scientists say the therapy taps into the spinal circuitry responsible for walking motions. It's well known that nerves in the spine do not need to talk to the brain to trigger rhythmic muscle motions and "step-like walking."
Previous studies have shown that tapping into this circuitry can help patients with spinal cord injuries achieve leg motion but, until now, no one has been able to manipulate it in a way that allows for full weight-bearing and sustained stepping.
In this study, after several weeks of treadmill training, the rats could put all their weight on their legs and even move them forward, backward, and sideways similar to voluntary walking.
The findings, presented in this week's online edition of Nature Neuroscience, suggest that severed nerve fibers do not need to regrow in order for a paralyzed patient to walk again. The study researchers hope their discovery leads to a new strategy for restoring motor function in people with spinal cord injuries. Even after the combo therapy, the rats still needed assistance walking, but researchers say neuroprosthetic devices would help people with this task.