Soldiers exposed to roadside bombs appear to have the same degenerative brain disease—chronic traumatic encephalopathy (CTE)—that has been found in the brains of athletes who have been repeatedly concussed, according to a new study published May 16 in the journal Science Translational Medicine.
CTE can cause memory loss, personality changes, impaired judgment, dementia and depression. The new study is the second time that researchers have found signs of CTE in veterans, and the report indicates that immobilizing the head could significantly reduce the brain trauma.
According to the New York Times, the findings are "the strongest evidence yet that…combat veterans with invisible brain injuries caused by explosions are at risk of developing long-term neurological disease."
Researchers at Boston University School of Medicine performed autopsies on four veterans, four athletes and four individuals with no record of brain injuries. In all of the veterans and athletes, they found "indistinguishable" evidence of CTE, including:
- Abnormal clusters of toxic protein;
- Dead or dying neurons; and
- Damaged axons.
The study also examined the impacts of simulated blasts on mice, using compressed nitrogen to burst a Mylar membrane and create force equal to a 120-millimeter mortar round. When mice were able to move their heads freely during the explosion, researchers found that the wind from the explosion shook their skull violently and two weeks later the mice had signs of CTE. When the animals' heads were immobilized, they did not develop CTE.
Takeaways and reactions
The Times notes that the study raises questions about whether military veterans who struggle with emotional issues are suffering from psychiatric problems or lingering brain injuries. If the findings are confirmed, there would be "profound implications for military policy, veterans programs and future research," the Times adds.
Several professionals have questioned the study's methods, citing too small of a sample group or unclear conclusions (Dao, New York Times, 5/16; Walsh, MedPage Today, 5/16).