Blast-Induced Traumatic Brain Injury: Using a Shock Tube to Recreate a Battlefield Injury in the Laboratory

Explosive detonation has been a longstanding battlefield concern for the U.S. Army. Recently, emphasis has shifted to blast injury to the brain since blast has emerged as the predominant cause of neurotrauma in current military conflicts, and its etiology is largely undefined. Using a compression-driven shock tube to simulate blast, we are assessing the physiological, neuropathological, and neurobehavioral consequences of airblast exposure. Blast generates an air shock front imparting effectively instantaneous increases in static and dynamic pressure conditions. The positioning of the experimental subject within the shock tube greatly influences the exposure conditions and determines the relative contributions of these side-on and dynamic pressures to the injury. The pressure exposures and brain injuries resulting from airblast exposure at different shock tube positions are reviewed. Shock tube exposures provide survivable blast conditions under which striking neuropathological changes can be generated and TBI can be studied. These findings demonstrate that shock tube-generated airblast can cause TBI in rats, and point to the utility of this experimental tool in the development of effective therapies and countermeasures.