Rising consciousness of the severe, abiding repercussions of sturdy impacts to the head—concussions, mild traumatic brain injury, neurological issues—have led scientists to focus on what precisely happens inside a skull during a big hit.
Mehmet Kurt, a mechanical engineer at Stevens Institute of Technology who studies the biomechanics of the brain and the cranium at rest and through rapid head movements, has now bioengineered simulations that monitor how the brain behaves upon impact, building the inertial stresses and pressures that control inside a mind that has just been struck from the side.
By analyzing a mix of simulated and human data of brain movement which have led to concussions, Kurt and his team, along with Stevens graduate student Javid Abderezaei, digitally show that side impacts to the head result in rotational accelerations that make mechanical vibrations to concentrate in two brain areas: the corpus callosum, the bridge that connects the hemispheres, and the periventricular area, white matter sections at the brain’s root that assist in speeding muscle activation.
Kurt and Abderezaei, with Kaveh Laksari of the University of Arizona and Songbai Ji of Worcester Polytechnic Institute, discovered that the cranium’s internal geometry and the viscous nature of the brain cause these two areas to resonate at particular frequencies and receive more mechanical power in the form of shearing forces than the rest of the mind. More shear strain presumably produces more tissue, and cell damage, notably since shear, opposing motions tend to damage brain tissue more quickly than other biological tissues.