Trauma from exposure to a single improvised explosive device (IED) blast can result in long-term brain impairment, according to new research.

The study, published today in the journal Science Translational Medicine, is the first to examine postmortem brains of U.S. military personnel who were exposed to a blast and/or a concussive injury.

It found evidence that a single blast from a typical IED can cause traumatic brain injury (TBI) and chronic traumatic encephalopathy (CTE).

CTE is a progressive degenerative disease of the brain found in athletes and others with a history of repetitive brain trauma that leads to brain tissue death. Like TBI, which is considered to be its precursor, CTE results in psychiatric symptoms (e.g. personality changes, depression) and long-term cognitive disability (e.g. memory loss, impaired judgment, dementia).

The team of researchers — which included eminent CTE expert Dr. Ann McKee as well as leading experts in blast physics, experimental pathology and neurophysiology — investigated the brains of four military personnel with known blast exposure and compared them to brain tissue samples from four athletes who had a history of repetitive concussive injury and four comparably-aged people with no history of concussions or neurological disease.

The investigators found that the signs of CTE in the military veterans resembled those in the athletes and were consistent with brain samples from other athletes examined by McKee at the Center for the Study of Traumatic Encephalopathy in Massachusetts.



When examining the effects of a single blast exposure, they found that long-term impairments in brain functions were observed in mice just two weeks after exposure to a single blast.

In a press release, researchers estimated that TBI may affect 20 percent of the 2.3 million servicemen and women deployed since 2001.

More from the press release (via EurekAlert!):

"Our laboratory experiments show that blast exposure can produce both structural and functional damage that may be long-lasting and is likely to underlie the profound cognitive, memory, and perhaps mood and post-traumatic stress disorders, experienced by many soldiers," said [Dr. Patrick] Stanton, who is director of the Neural Systems Laboratory at [New York Medical College].

Researchers found that the blast wind from an IED — at a velocity of up to 330 miles per hour — as opposed to the shock wave leads to TBI and CTE, but immobilizing the head during blast exposure in mice prevented the learning and memory deficits associated with CTE.

Nevertheless, making sure the skull doesn't shake is easier said than done.

Dr. Lee Goldstein, associate professor at Boston University School of Medicine, stated that the results were encouraging to efforts concerned with the diagnosis and rehabilitation of traumatic brain injuries:

"Our study provides compelling evidence that blast TBI and CTE are structural brain disorders that can emerge as a result of brain injury on the battlefield or playing field," Goldberg said. "Now that we have identified the mechanism responsible for CTE, we can work on developing ways to prevent it so that we can protect athletes and our military service personnel."

Here's a YouTube video showing what it's like to be hit by an IED (via VideoblastViral):