| Radiation therapy combined with microsurgery shows promise for curing injured spinal cord |
Published
07/24/2007
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Cure Research , July 2007
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"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."
By Public Library of Science,
[RxPG] 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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