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.
Kalderon and her colleagues at Sloan-Kettering then made
longitudinal micro-incisions down the center of the injured cord within
the first 24 hours after injury to release the fluid buildup. There was
significant reduction in the size of lesion site, confirming Allen's
work. They then combined the radiation treatment with the microsurgery.
When a midline incision was performed at one hour after injury,
followed by localized radiation therapy given for ten days starting on
day ten after injury, there was nearly a two-fold improvement in the
body's ability to heal the injured cord compared with untreated rats.
This suggests that fluid accumulation and swelling must first be
prevented if the radiation therapy is to be effective in promoting
wound repair.
The researchers were able to show the improvements in wound
healing both by post-mortem examination of the tissue three months
after injury, as well as
MRI on the living rats. This indicates that
the success of these therapies on humans could also be evaluated using
MRI technology.
The researchers also tested a third level of treatment.
Recognizing that exercise may increase tissue repair, they added ten
minutes of treadmill exercise five days a week to the radiation
therapy, starting at the second week after injury. Again, the spinal
cord ability to repair itself was markedly improved. Rats treated with
incisions to reduce the harmful fluid accumulation, followed by
radiation therapy at the site to remove damaging cells and regular
treadmill exercise saw a three-fold improvement in the body's ability
to repair the severely crushed cord, going from 19% of cord tissue that
was healthy in untreated rats to 56.3% of cord tissue that was repaired
and saved from further damage.
"This research provides hope for spinal cord injury victims
that paralysis can indeed be prevented or repaired with a combination
of conventional therapies at the time of injury," according to
Kalderon.
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Article adapted by Medical News Today from original press release.
