Research on rats with crushed spinal cords, similar to human injury, reveals that treatment soon after injury combining radiation therapy to destroy harmful cells and microsurgery to drain excess fluids significantly increases the body's ability to repair the injured cord leading to permanent recovery from injury, according to the study published in the July 18 peer-reviewed journal PLoS ONE.
Since repair of damaged cord directly correlates with prevention of paralysis, this research demonstrates that conventional clinical procedures hold promise for preventing paralysis from spinal cord injuries.
Currently there is no cure for human spinal cord injury. Treatment after injury is largely limited to steroids administered to prevent further deterioration.This research opens the door to developing a clinical protocol for curing human spinal cord injuries using conventional therapies, said lead researcher Nurit Kalderon, Ph.D. Conducted at Sloan-Kettering Institute for Cancer Research in New York City, the research was supported by a grant from the National Institute of Neurological Disorders and Stroke (NINDS).
The hallmark of spinal cord injury is progressive tissue decay at the damage size. Kalderon's previous research indicated that the spinal cord is able to repair itself in the early days after injury but is thwarted in its efforts during the second or third week by certain cells that block the repair process.
In earlier research on rats with cords that were completely severed, Kalderon was able to show that radiation therapy, similar to that used in cancer treatment, given localized at the lesion site during the third week following injury helped the spinal cord heal itself by eliminating the cells that interfere with its natural repair processes. The research established a connection between the body's ability to repair the wounded cord and recovery of motor function. Once the wound was healed, the severed brain-cord fibers could grow across the lesion site, restoring the connection between the brain and the spinal cord, with resulting restoration of control of the brain over muscle function.
In the current research, the scientists made a severe crush injury, similar to a human contusion/fracture injury, in spinal cord of adult rats just below the waist. In crush injuries, tissue decay is exacerbated by the secondary damage caused by massive swelling as fluids build up from the injured blood vessels. When the researchers administered radiation alone, there was no detectable beneficial effect on the body's repair of the crushed cord. However, the researchers recalled findings from nearly a century ago by Alfred R. Allen showing that incision at the damage site along the midline of the cord (myelotomy) could drain the accumulated fluids and reduce tissue damage.