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Thousands of U.S. troops in Iraq and Afghanistan sustained concussions and other brain injuries from roadside bombs. But a new study suggests these injuries are not leading to a brain condition often seen in former boxers and football players. NPR's Jon Hamilton reports.
JON HAMILTON, BYLINE: In contact sports, concussions increase the risk of chronic traumatic encephalopathy, or CTE. It's a brain condition associated with dementia and a range of psychiatric disorders, so many doctors have worried that CTE might be a factor in the mental health problems experienced by U.S. combat troops exposed to bomb blasts. Dr. Daniel Perl is a professor of pathology at the Uniformed Services University in Bethesda.
DANIEL PERL: Their families were saying that their personalities had changed. They were having trouble sleeping. We know that the suicide problem is substantial. PTSD is prevalent.
HAMILTON: CTE can only be diagnosed after death, so Perl and a team decided to study a collection of brains donated by the families of deceased service members.
PERL: We said this was the opportunity to look at those brains and see how much CTE played a role in this problem.
HAMILTON: The team looked at 225 brains, including many from military personnel who'd been exposed to bomb blasts. Perl says CTE was rare.
PERL: We could only find 10 cases that met the diagnostic criteria for CTE. And then we found that all 10 had played contact sports.
HAMILTON: The numbers are too small to say that contact sports caused the condition, but Perl says the findings, which appear in the New England Journal of Medicine, do support another conclusion.
PERL: Serving in the military and being exposed to blasts is probably not a significant risk factor for developing CTE.
HAMILTON: Perl says that's a good thing, but he adds that bomb blasts do injure the brain in ways that can have lasting effects.
PERL: One shouldn't go away thinking that because we didn't find CTE, the brain's normal. That's clearly not the case.
HAMILTON: Perl says a growing body of evidence shows that exposure to bomb blasts can raise the risk of problems like PTSD. Jon Hamilton, NPR News.
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