Biomechanics of Blast TBI With Time-Resolved Consecutive Primary, Secondary, and Tertiary Loads

Abstract

Blast-induced traumatic brain injury (bTBI) has become a signature casualty of recent military operations. In spite of significant clinical and preclinical TBI research, current understanding of injury mechanisms and short- and long-term outcomes is limited. Mathematical models of bTBI biomechanics may help in better understanding of injury mechanisms and in the development of improved neuroprotective strategies. Until present, bTBI has been analyzed as a single event of a blast pressure wave propagating through the brain. In many bTBI events, the loads on the body and the head are spatially and temporarily distributed, involving the primary intracranial pressure wave, followed by the head rotation and then by head impact on the ground. In such cases, the brain microstructures may experience time/space distributed (consecutive) damage and recovery events. The paper presents a novel multiscale simulation framework that couples the body/brain scale biomechanics with micro-scale mechanobiology to study the effects of micro-damage to neuro-axonal structures. Our results show that the micro-mechanical responses of neuro-axonal structures occur sequentially in time with “damage” and “relaxation” periods in different parts of the brain. A new integrated computational framework is described coupling the brain-scale biomechanics with micro-mechanical damage to axonal and synaptic structures.

Understanding Primary Blast Injury: High Frequency Pressure Acutely Disrupts Neuronal Network Dynamics in Cerebral Organoids

“…Second, the pressure exposures have some limitations. Computer simulations 52 , 53 and human phantom modeling suggest during blast exposures intracranial pressure cycles are composed by a mixture of multiple frequencies 54 —with a majority of power contained in the range up to 5 kHz—and decay on the order of 10 msec. Thus, the loading cycles chosen in this study do not represent pressure cycles specific to any blast exposure scenario.…”