A big bang theory of big brain trauma

One of the biggest neurophysiological science news headlines of the 2024 summer reported a critical link between post-traumatic stress disorder (PTSD), suicide, and brain injury from blast events in members of the elite US fighting force, Navy SEALS. Researchers from the Department of Defense/Uniformed Services University Brain Tissue Repository (DOD/USU BTR) had discovered a border of neural damage between the layers of white and gray matter comprising the cortical folds of service members’ brains. Described as a distinctive anatomical line of astroglial scarring along the shared junctions of gray and white cellular zones of the brain, this tissue injury was unlike that observed for concussive brain trauma. Rather, it was consistent with blast biophysics of mammalian tissues. In this new study, the damage appears to be correlated with long-term, repeated exposure to blast waves from nearby explosions or firing weapons. A cascade of progressive unexplained behaviors, cognitive decline, and severe depression in the trained fighters ensued. This analysis suggested that repetitive, impulsive pressure waves traveling through the service members’ heads and brains with each blast had compromised their cognitive centers, setting a downward trajectory in their mental and physical health.