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Combat veterans' brains reveal hidden damage from IED blasts

The brains of some Iraq and Afghanistan combat veterans who survived blasts from improvised explosive devices (IEDs) and died later of other causes show a distinctive honeycomb pattern of broken and swollen nerve fibers throughout critical brain regions, including those that control executive function. The pattern is different from brain damage caused by car crashes, drug overdoses or collision sports, and may be the never-before-reported signature of blast injuries suffered by soldiers as far back as World War I.

Vassilis Koliatsos, M.D., professor of pathology, neurology, and psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine, recently published a study in Acta Neuropathologica Communications that found survivable blasts may cause hidden brain injuries that play a role in the psychological and social problems some veterans face after coming home.

"This is the first time the tools of modern pathology have been used to look at a 100-year-old problem: the lingering effect of blasts on the brain," says Koliatsos, senior author of the study that used molecular probes to reveal details in the brains of veterans who died months or years after an IED blast. "We identified a pattern of tiny wounds, or lesions, that we think may be the signature of blast injury. The location and extent of these lesions may help explain why some veterans who survive IED attacks have problems putting their lives back together."

 

Soldiers have struggled with bomb-induced brain damage since 1914, when German and Allied forces tried to blast one another out of entrenched positions with monthslong bombardments. Many World War I fighters survived the barrage outwardly unscarred, but with an array of cognitive and psychological difficulties known as shell shock. After World War I, mass bombardments of troops were rare, and shell shock became uncommon. Now renamed blast neurotrauma or blast injury to brain, it has re-emerged due to insurgent forces' widespread use of IEDs in Iraq and Afghanistan.

To understand this puzzling ailment, a team of eight researchers examined the brains of five male United States military veterans who survived IED attacks but later died. The remains were donated to the Armed Forces Institute of Pathology. Three died of methadone overdoses that could have been accidental, Koliatsos says, since the drug is commonly prescribed to treat soldiers' chronic pain. One died of a gunshot wound to the head, and one died of multiple organ failure. The researchers compared the veterans' brains to those of 24 people who died of a range of causes, including motor vehicle crashes, opiate overdoses and heart attacks.