A generation of Iraq and Afghanistan veterans exposed to explosions may be at risk for early-onset dementia, according to a new study that looked at the autopsied brains of four former combat service members and four athletes.
Scientists said their work showed evidence of a progressive degenerative brain disorder known as chronic traumatic encephalopathy (CTE), a disease found in recent years among deceased professional football players who had suffered multiple concussions.
What researchers said was particularly alarming was evidence that the disorder could result from exposure to a single blast.
"Ramifications are that these hundreds of thousands of military personnel are at risk for this disorder. It doesn't mean by any means that they all have or will get it. But they are at risk for it," says Ann McKee, a Department of Veterans Affairs scientist and co-author of the study in Science Translational Medicine.
The study findings were based on comparing brain autopsies of four Iraq and Afghanistan veterans with four young athletes, as well as studying mice exposed to a simulated blast.
Brain-trauma scientists who treat or study soldiers and Marines who suffer combat brain injuries applauded the study for focusing attention on CTE but questioned some of the conclusions.
Given the limited number of brain autopsies in the study, Army Col. Geoffrey Ling cautioned against sweeping conclusions about risks to veterans in the future.
Daniel Perl, professor of pathology and a neuropathologist at the Uniformed Services University of the Health Sciences, says the findings will spur more research.
"It's not the whole story. It's just the beginning," he says.
Progression of CTE -- which is marked by memory loss, suicidal thoughts and aggression -- is slow, but appears to be irreversible after eight to 10 years, with the prospect of early dementia within a few decades, the scientists say.
"We need to find some answers quickly so that we can treat veterans, military personnel, before anything gets worse," says the study's lead author, Lee Goldstein, a scientist with Boston University.
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