Grey/White Boundary 1 | Grey/White Boundary 2
The scattered character of Diffuse Axonal Injuries (DAI) can be replicated by means of the nonlinear fluid TBI model. If cg > cw, the introduction of the nonlinear material derivative triggers scattered turbulent oscillations near the gray/white matter boundary characterized by much higher velocity magnitudes than are predicted by the linear Kelvin-Voigt model or the nonlinear stress-strain model (left panels). Thus, the fluidity of the brain matter seems to cause the random scattering of DAI. Using the dually-nonlinear TBI model, which includes both the nonlinear material derivative and the nonlinear stress-strain relation, enhances the turbulent character of the oscillations at the gray/white matter boundary as well as within two regions in the white matter (right panels). Changing the position or/and the direction of the rotational axis (as it happens in traumatic scenarios) scatters the oscillatory vortices into the other brain regions. Thus, the interaction of both nonlinearities seems to satisfactorily explain the key DAI features.