The brain is the real hurt locker
SOLDIERS exposed to roadside bomb blasts and athletes who have suffered repeated concussions show the same long-lasting changes to brain cells.
A new study connects two growing – and for many sufferers, chronically debilitating – health problems in the United States. It adds to the evidence that injuries once officially termed ‘‘mild’’ may be anything but.
Specifically, head trauma that doesn’t knock a person unconscious may nevertheless kill some brain cells and damage the architecture of others, setting up a semipermanent state of brain inflammation. That may lead to the foggy thinking and poor memory that thousands of soldiers and football players experience even after they’ve ‘‘recovered’’ and have been sent back to the battlefield or playing field.
‘‘Whether your head is accelerating because you’ve been hit by a linebacker or the blast from an exploding [improvised explosive device], the injury to the brain appears to follow a similar course,’’ said Lee Goldstein, a doctor and neuroscientist at Boston University who co-led the study, published in Science Translational Medicine.
The abnormalities found in the brains of soldiers and athletes studied after death are similar to those found in the brains of mice exposed to the equivalent of a moderate-size bomb blast, an experiment the 35-member research team also conducted.
The study doesn’t suggest ways to prevent or treat blast injuries in soldiers or concussions in athletes. The researchers hope that future mouse experiments may point in that direction. But the findings will almost certainly draw more attention to a problem that’s now part of the medical histories of thousands of Americans.
‘‘The take-home message is that concussions need to be taken seriously at all ages,’’ said Ann Mckee, a neuropathologist with the Veterans Affairs Boston Healthcare System. ‘‘We don’t want our kids exposed to these injuries in the pursuit of amateur athletics.’’
Traumatic brain injury (TBI) has been called the ‘‘signature wound’’ of the Iraq and Afghanistan wars.
Akey question is whether a blast alone can cause permanent brain damage, as opposed to a blast that smashes a soldier’s head against a solid object, such as a vehicle roof. By one estimate, more than 320,000 soldiers may have experienced such ‘‘pure’’ blast exposures over the past decade.
For athletes, the picture is similarly confusing. Football and hockey players whose brains end up in neuropathology labs tend to be ones who’ve had many concussions.
The Boston researchers tried to minimize these problems by looking at deceased young adults whose history of head trauma was known. In all cases, however, the subjects had more than one brain injury.
Using both conventional and electron microscopes, they studied the brains of 12 men, most in their 20s. The brains of the four veterans and four athletes each showed a loss of neurons and damage to axons, the wirelike filaments that allow neurons to communicate with each other. The brain cells also showed tangles of ‘‘tau protein’’, a substance found in axons. That second abnormality is the central feature of ‘‘chronic traumatic encephalopathy’’.