| Professor Works to Increase Understanding of Spinal Cord Injuries |
| Published
10/4/2006
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Knowledge , October 2006
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Unrated |
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| Mehmet
Bilgen, PhD, director of high field magnetic resonance imaging research
at the Hoglund Brain Imaging Center and associate professor of
molecular and integrative physiology at the KU School of Medicine |
Every year about 11,000 people in the US suffer spinal cord injuries
that will likely change their lives forever. More than half of these
people are younger than 30. Today’s treatments can’t
completely help the 250,000-400,000 people currently living with spinal
cord injuries, but researchers at KU Medical Center’s Hoglund
Brain Imaging Center are working to change that.
“Spinal cord injury is a major health and socio-economic
problem,” said Mehmet Bilgen, PhD, director of high field
magnetic resonance imaging research at the Hoglund Brain Imaging
Center.
Current Research
Bilgen, who is also associate professor of molecular and integrative
physiology at the KU School of Medicine, serves as principal
investigator on two current research projects. He recently received two
National Institutes of Health grants totaling nearly $730,000 to study
the progression of spinal cord injuries in longitudinal animal studies.
“Research on the neural fibers and vascular systems of animal
spinal cords holds great potential for better understanding of spinal
cord injuries and, ultimately, for better clinical treatment,”
Bilgen said. The other investigators in these projects are Barry W.
Festoff, MD; Randy Nudo, PhD; Paul Arnold, MD; Baraa Al-Hafez, MD; Yong
Yue He, MD; Charles Little, PhD and Sandra Hall, PhD.
Methods of Discovery
While all spinal cord injuries recover to a limited extent, severe
injuries can cause life-long paralysis and almost insurmountable
disabilities related to pain, bladder control and upper extremity
functions. The brain communicates with the body through neural fibers
in the spinal cord, so the outcome of an injury is determined by how
much damage is done to the neural fibers. If the spinal cord is
completely severed, paralysis below the point of injury occurs. If only
some of the neural fibers are damaged, sensory and Motor function may
only be impaired.
Part of Bilgen’s research focuses on identifying viable neural
fibers after an injury using manganese-enhanced magnetic resonance
imaging (MRI). Manganese serves both as an MRI contrast agent and in
vivo neuroal tract tracer. Researchers can follow manganese via MRI as
it is uploaded and transported down the undamaged fibers to the point
of injury.
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| MRI
of rat spine in sagittal view. The thin teal rectangles denote the
slice locations where the spinal cords below are imaged, with the
injury highlighted in 2. |
Some of the manganese travels across the injury to the fibers below it.
This suggests neural tissue bridging across the injury, possibly
because it survived the injury or was restored afterward. “This
should form a basis for testing new therapies for promoting fiber
connectivity, understanding spinal cord Plasticity and improving
Functional recovery from spinal cord injury,” Bilgen said.
Survival of some fibers within these tracts may promote recovery,
repair and/or Regeneration of other fibers. This process is known as
“endogenous plasticity” and the group lead by Barry W.
Festoff, MD, professor of neurology and pharmacology and director,
Neurobiology Research Laboratory at the Kansas City VA Medical Center,
focuses on means to enhance this built-in ability of the body to
promote healing and recovery. “The ability to detect these fibers
by Dr. Bilgen’s techniques could lead to new treatments and
paradigm shifts that restore some or even most of the lost
functionality in spinal cord injured patients,” Festoff said.
Vascular Research
Bilgen and his team are also using magnetic resonance angiography to
study how blood vessels change and repair after a spinal cord injury.
When blood vessels are damaged in the injury, blood supply to the
spinal cord becomes disrupted. In response to the injury, new vessels
are formed.
Understanding the way the vascular system changes after an injury could
improve treatment and the eventual physical outcome for the patient.
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| MRI
of cross section of spinal cord above the injury, at the injury
epicenter and below the injury, respectively. Image1 shows Manganese in
live corticospinal tract (CST) neural fibers shown in the bright gray
round dot near the center (arrow). Image 2 shows few live fibers (arrow
head) at the injury site. Image 3 shows some Manganese that has
traveled down the spinal cord across the injury, suggesting viable
neural fibers exist at the injury site. |
“This will be a large step forward in understanding the recovery
mechanisms. In the long term, it will provide objective assessment of
potential new therapies with the power to manipulate the spinal cord
vasculature to improve the neurofunctional outcome,” Bilgen says.
Bringing It All into Focus
While the human spinal cord may be as wide as your finger, the spinal
cord of a rat or mouse is only as wide as the tip of its tail, with a
vascular system even smaller. Previous imaging techniques were too
low-resolution to view the tiny elements of rat and mouse physiology.
Researchers in the past had to use many animals and dissect them at
each stage of injury.
With new MRI techniques, researchers can follow the injury in one
animal and take images at each stage. This allows them to use fewer
animal subjects and to track the injury in a natural Environment.
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| Images
of a rat spinal cord. The arrow points to the area of injury. The
angiogram on the left shows injury where blood vessels were damaged and
are lacking. The image on the right shows the actual spinal cord with
injury. |
At the Hoglund Brain Imaging Center, Bilgen uses a technique he
developed called inductively- overcoupled coil technology. It uses a
small implanted radio frequency coil and a larger tunable external
coil. The combined coils act as a transformer to allow for high quality
and high resolution MRIs.
“You won’t be able to believe how beautiful these images are to me,” Bilgen says of the high resolution MRIs.
Hope for the Future
There may be no cure for severe spinal cord injuries and their
life-altering effects today, but researchers are working to get closer
and closer. The work being done at Bilgen’s laboratory offers
hope of continually improving treatment for those living with spinal
cord injuries.
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