A study published on Thursday in The Lancet Neurology has linked tissue damage to blast injuries, further connecting PTSD to changes in the brain and not solely a psychological response to exposure to battle. Of the 2.5 million United States service members who have served in Iraq and Afghanistan, a 2008 study by the RAND Corporation suggested than 500,000 were exposed to blasts. A 2014 study of 34 living veterans from those conflicts indicated that the majority had experienced at least five blasts. Exposure to explosions is the source of a vast number of injuries experienced by military personnel, including fatal brain injuries and concussions.
The “blast wave” phenomena has been poorly understand as a mechanism of injury until now. The blast is composed of a pulse of compressed air moving in all directions faster than the speed of sound and arriving before the wind from the blast. This wave affects brain tissue as it moves through the helmet and skull. The blast wave also affects blood vessels by compressing the sternum and sending shock waves through the body’s blood vessels into the brain. Researchers found scarring in specific locations in the cerebral cortex associated with emotional and cognitive functioning. Of the five men studied all had symptoms of PTSD, suggesting that a physical injury to the brain led or exacerbated their psychological problems according to Dr. Daniel Perl, the neuropathologist who led the study.
For individuals suffering from PTSD and their families, the study may offer some explanations for the cognitive and emotional problems. For Ms. Jennifer Collins, the wife of David Collins, a 17 year Navy Seal veteran who was exposed to countless explosions and killed himself in 2014, the study provided Ms. Collins with “proof that this man died in combat”. Mr. Collins’ brain on autopsy also showed signs of CTE which has been known to contribute to psychiatric conditions .
The study provides preliminary evidence for further exploration, But, importantly, it begins to forge a link between PTSD and structural changes to the brain caused by blast exposure. We have had a vast number of soldiers exposed to blast injuries in Iraq and Afghanistan, what remains unknown is how many have experienced an injury resulting in structural change to the brain and how many will develop psychological problems associated with PTSD later. The high rate of suicide among returning veterans is a compelling reason to move these studies forward to establish early detection methods and more effective interventions.