New Technique Used on Old Rats Offers New Hope for
Delayed Stroke Treatment
Loyola researchers hope to reverse stroke damage by
jumpstarting growth of nerve fibers
Aug.
25, 2008 - If a stroke patient doesn't get treatment within
approximately the first three hours of symptoms, there's not much
doctors can do today to limit damage to the brain. A new technique used
on rats that have experienced strokes in old age, however, could
potentially restore functions to patients weeks or even months after a
stroke.
This technique involves jumpstarting the growth of
nerve fibers to compensate for brain cells destroyed by the stroke.
Most women who rated their risk "low" were far more
accurate than the men
July 14, 2008 - Men, up to age 75, who believed they were at
lower-than-average risk for cardiovascular disease actually experienced
a three times lower incidence of death from heart attacks and
strokes.
Slowed reflexes, sagging posture and other small
neurological problems need more attention in elderly patients
June
23, 2008 If you are elderly say 72 or so and show subtle signs of
reflexes that are not so quick, a posture that sags and maybe another
slight neurological problem or two, there is evidence from a new study
that you may be in danger of a stroke or death, even if you appear to be
otherwise healthy.
"In the best-case scenario, this would open up the
window of time that people could recover and go back to normal
functional status," said Gwendolyn Kartje, MD, Ph.D., a professor in the
department of cell biology, neurobiology and anatomy and department of
neurology at Loyola University Chicago Stritch School of Medicine in
Maywood, Ill. and chief of neuroscience research at Edward Hines Jr. VA
Hospital in Hines, Ill.
Kartje and colleagues described the experimental
approach, called anti-nogo-A immunotherapy, in a recent review article
in the journal Topics in Stroke Rehabilitation.
Anti-nogo has dramatically improved functions in
lab animals that have experienced strokes. And an ongoing clinical trial
in Europe and Canada is testing anti-nogo in humans who have suffered
spinal cord injuries.
Most strokes are caused by clots that block blood
flow to one part of the brain, killing brain cells within hours. The
drug TPA can minimize damage by dissolving the clot. But TPA is safe and
effective only when given within about three hours of the onset of
symptoms. Most patients don't receive treatment within that brief
window. Patients typically arrive at the hospital too late, or hospitals
do not begin administering TPA soon enough.
Anti-nogo is among several new approaches under
study that potentially could reverse stroke damage, researchers wrote.
Nogo-A is a protein that inhibits the growth of nerve fibers called
axons. It serves as a check on runaway nerve growth that could cause a
patient to be overly sensitive to pain, or experience involuntary
movements. (The protein is called nogo because it in effect says to
axons: "No go.") In anti nogo immunotherapy, an antibody disables the
nogo protein.
The left side of the brain controls movements on
the right side of the body, and vice versa. Thus, a stroke on the left
side of the brain can cause paralysis on the right side of the body. In
such a patient, anti-nogo would, it's hoped, spur the growth of axons
from the healthy right side of the brain. These axons would then grow
into the right side of the body and restore functions lost by the
stroke.
Anti nogo has been tried on rats that have
experienced strokes in old age. As in people, strokes in rats affect one
side of the body. Following strokes, the rats were unable to pick up
pellets of food with the front paw on the affected side. After anti-nogo,
function in this paw was almost completely restored in some rats.
The Swiss pharmaceutical company Novartis is
sponsoring a phase 1 clinical trial of anti-nogo for patients paralyzed
by spinal cord injuries. Kartje believes anti-nogo also has great
potential for stroke patients. A clinical trial for stroke patients
could begin as early as 2012, she said. Loyola is among the potential
sites for such a trial.
Anti nogo "offers the potential for stroke patients
to recover, return to nearly normal functional status, and stay out of
nursing homes," Kartje said. "Theoretically, there's no reason why this
should not happen."
Editors Notes:
Kartje began studying the nogo protein in 1992, and
has published numerous papers on the topic. Her lab at Hines is funded
by the Veterans Administration, with additional funding from the
National Institutes of Health, Neuroscience Institute at Loyola
University Chicago Stritch School of Medicine, Falk Foundation and
Illinois Regenerative Medicine Institute.
Based in the western suburbs of Chicago, Loyola
University Health System is a quaternary care system with a 61-acre main
medical center campus, the 36-acre Gottlieb Memorial Hospital campus and
22 primary and specialty care facilities in Cook, Will and DuPage
counties.
Aug.
25, 2008 - If a stroke patient doesn't get treatment within
approximately the first three hours of symptoms, there's not much
doctors can do today to limit damage to the brain. A new technique used
on rats that have experienced strokes in old age, however, could
potentially restore functions to patients weeks or even months after a
stroke. 