When military personnel fire certain powerful weapons, they are exposed to a blast wave that sends blood surging from the body to the brain.
This “tsunami in the body” is one way a blast can injure blood vessels that supply oxygen and nutrients to structures deep in the brain, says Dr. Ibolja Cernak, an expert on blast injuries at Belmont University in Nashville.
“We are talking about the brainstem, we are talking about the cerebellum,” Cernak says, “all of the very nicely cushioned brain structures.”‘
In animals, there is now strong evidence that these structures can be damaged by blast exposures that disrupt blood vessels. In veterans, the effects are harder to measure.