Philip Bayly, Ph.D.,
Lilyan and E. Lisle Hughes Professor in Engineering, Guy Genin, Ph.D.,
assistant professor of mechanical engineering, and Eric Leuthardt, MD,
formerly a resident at Barnes-Jewish Hospital, now at the University of
Washington, tested seven subjects in an MRI and gathered data that show
that the brain, connected to the skull by numerous vessels, membranes
and nerves at the base, tries to pull away from all those attachments,
leading to a significant deformation of the front of the brain.
Bayly discussed the
group's findings Nov. 10, 2005, at the annual meeting of the National
Neurotrauma Society in Washington, DC.
According to Genin,
the subjects are placed in the soft netting of a head guide, and are
asked to raise and lower their heads about an inch inside an MRI
machine. The process is repeated several times as the MRI pieces
together a complete movie of the brain's response to these skull
motions.
"Phil (Bayly) has
developed a set of state-of-the-art hardware and software to synchronize
and analyze all of these measurements," said Genin. "The systems he has
developed will allow us to explore a broad range of questions critical
to understanding mild traumatic brain injury."
"It's an interesting
thing that in many occipital impact injuries, people often find the
greatest injury in the front of the brain," Bayly said. "That has been a
puzzle for a long time and there have been numerous different
explanations for it. What we see with the MRI is quite a bit of
mechanical deformation in the front of the brain when the skull is hit
from the rear. It seems to be because the brain is trying to pull away
from some constraints in the front of the brain."
Taking the guesswork
out
Bayly and his
collaborators can apply the levels of deformation they have found with
their subjects to in vitro experiments or to animal models to learn even
more about brain matter deformation. They have done experiments on
humans with the head dropping forward, and plan to study different
acceleration profiles, including rotations. "This method is a starting
point that we hope will take the guesswork out of brain matter
deformation analysis," Bayly said. "We can now quantify brain
deformation from these very low, mild accelerations with MRI. We are
working with Washington University School of Medicine faculty in hopes
of some day developing therapeutic remedies for traumatic brain injuries
and concussions.
"The most immediate
application of our data will be in the development and validation of
computer simulations of traumatic brain injury, which may ultimately
reduce the need for direct experimentation."
Bayly and Genin are
collaborating with David Brody, MD, Ph.D., instructor in neurology at
the Washington University School of Medicine, and Sheng K. Song, Ph.D.,
assistant professor of radiology, on other advanced MRI techniques with
the hope of finding noninvasive ways to detect and characterize brain
injuries.
Source: Washington
University in St. Louis
Published on 14th
December 2005