Yesterday on an international stage in Davos, Switzerland, President Donald Trump dismissed the reported injuries of American troops being treated for traumatic brain injury in Germany after an Iranian missile attack on the Al Asad Air Base in Iraq. No matter what one’s political views may be, Trump’s uninformed and potentially damaging pronouncement cannot go uncorrected.
I have been to Walter Reed Naval Hospital to share my scientific research and meet the healthcare professionals and members of our military who have suffered injuries from a concussion, which the armed forces term “invisible wounds of war.” The National Intrepid Center of Excellence (NICoE) on the grounds of the Walter Reed Medical Center is devoted to the diagnosis and treatment of such wounds, which can have devastating effects if not recognized and treated.
I have seen personally how ignorance on the part of high school administrators about concussion can compound the traumatic injuries suffered by students in athletic sports.
We have all come to understand the lifelong disability that professional football players can suffer from repeated concussions in sports.
I have studied blast injury in experiments on brain cells in my own scientific research. That research, studying the effects of shockwaves from a blast that does not cause impact or visible injury to the head, revealed two surprising findings.
First, is that human brain cells are remarkably sensitive to this type of injury—more so than animals used in most research. We found that human brain cells were impacted by blast forces that had no observable effects on rat brain cells. One factor, among others, may simply be that the human brain cells are so much larger than rat brain cells, and like a larger sail in the wind, they are impacted to a greater extent by the same force, but there are other reasons as well.
The second surprise was that it was not neurons that were most sensitive to blast injuries of the type service members experience in using explosives to breach walls or, as is the case in the recent missile strike in Iraq, people who are not hit directly by an explosive, but are nevertheless rocked by the forceful shockwave from the blast. Glial cells called astrocytes were the first to respond to the shock wave. The blast initiates a frantic wave of cell-cell communication between astrocytes signaling by calcium ions, and this launches a genetic response to manufacture a profusion of proteins that these cells pump out in response to injury. Not only astrocytes but also the brain’s immune cells called microglia, are the first responders to brain trauma of all kinds.
Work in my lab and others has revealed that the brain’s “white matter,” which is the cabling between nerve cells, is especially vulnerable to concussive injury. These cables can extend long distances across the brain and they become stretched and damaged by the sudden slamming of the brain against the inside of the skull after a blow to the head or from any rapid acceleration of the head—even without impact. These forces shear the fragile, Jello-like brain tissue and strip the insulation off these fibers (called myelin), which is made by another type of glial cell (oligodendrocyte). You don’t need a degree in neurology to understand this. Problems with connections and cabling are the most frequent source of dysfunctions in home theater systems. So too is brain function severely disrupted by damaging the brain’s cabling even though the damage may be invisible unless examined under a microscope.
There was a time when ignorance over concussion prevailed. Getting knocked out, “having your bell rung,” was no big deal. Coaches fixated on winning a game would send players who suffered a concussion back out into the game, amplifying the injury to the athlete and risking life-long disability. This kind of ignorance is no longer tolerable.
Originally published in Psychology Today on January 23, 2020