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Head
Injury
Introduction
Traumatic
brain injury is the most common cause of death in childhood. Traditionally,
the engineering and medical communities have assumed that children respond
as miniature adults, which influences protective equipment design and
clinical practice guidelines in treatment, and in diagnostic distinction
of violence-related injuries from unintentional injuries. However, using
computational simulations and conducting experiments with animals, humans,
anthropomorphic dolls, and tissues, our lab has determined that size is
not the only important factor. Rather, mechanisms of severe brain injury
also vary with the age of the child, because the mechanical properties
of the tissues and their functional thresholds change during development.
We have developed the only immature animal model that recreates the constellation
of diffuse brain injuries seen in children, and have used it to correlate
rapid head accelerations with histopathological and functional (behavior,
cognition, motor) responses in mild, severe, and even repeated head injuries.
We
have measured region- and age-dependent variations in brain and skull
properties, and the large strain nonlinear behavior and macroscopic anisotropy
of brain tissue,
and these data have had a profound impact on computational models of the
head. Our
work has demonstrated that regional tissue strain correlates with neural
and vascular structural failure. This finding formed the rationale
for investigators to deform isolated neural bundle preparations and determine
a relationship between the uniaxial strain and the degree of injury.
Current studies investigate new injury
therapeutic interventions in acute and chronically injured animals. In
a field filled with social, medical, and legal controversy, our research
program is redefining the paradigm for how traumatic head injuries occur
in children.
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