Explosions are obviously the most common cause of brain injuries for troops. But scientists don’t understand exactly how a blast damages the brain. And this limits their ability to prevent, diagnose, and treat the injury. Desperate for a breakthrough, one Navy researcher looked to some seemingly unlikely inspirations: propellers, submarines, and shrimp—and a phenomenon known as “cavitation,” which occurs when a shock wave compresses gas into tiny bubbles that then burst. Dr. Timothy Bentley, a program manager at the Office of Naval Research in Arlington, Virginia, told The Daily Beast he believes explosions could cause bubbles to form inside troops’ brains. The formation and subsequent popping of the bubbles could damage brain cells and, over time, contribute to a host of conditions. Post-traumatic stress. Loss of hearing and eyesight. Even Alzheimer’s.
Cavitation seems to explain the gradual, systemic breakdown that afflicts many troops who’ve been exposed to bomb blasts: depression and post-traumatic stress followed by cognitive and sensory deterioration and, in some cases, early-onset Alzheimer’s. If they can prove the cavitation theory, there are practical steps the military can take to protect troops, Bentley said. “These blast forces are now striking the head and penetrating into the head and that can occur even with the helmets we have,” he explained. “It may be helpful to have face shields that deflect forces around the head. We might be better able to understand how to make helmets.” Bentley said that proving cavitation’s role in brain injuries could also lead to different military tactics as well as to treatments for traumas that have already occurred.