Originally published June 13, 2010 at 10:00 PM | Page modified June 14, 2010 at 5:07 PM

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Troops suffer long-term brain impacts from shock waves, Seattle study finds

Seattle researchers from the VA and the UW, with the aid of sophisticated scanning technology, have found long-term changes in brain functions of Iraq veterans exposed to blast shock waves.

Seattle Times staff reporter

More on traumatic brain injuries

A recent series of investigative reports by National Public Radio and ProPublica, an investigative journalism nonprofit, explores how the military medical system is failing to diagnose and treat brain injuries among many who served in Iraq and Afghanistan. Those stories are available at More information about traumatic brain injury can be found at the Defense and Veterans Brains Injury Center (


Seattle researchers, with the aid of sophisticated scanning technology, have found long-term changes in brain functions of Iraq veterans exposed to blast shock waves.

The findings have been published online in the journal NeuroImage, amid a contentious debate among doctors about the causes of memory loss, mood swings, insomnia and other symptoms that afflict some troops shaken up in bomb blasts or other explosions.

Some researchers believe that the brain quickly heals from mild brain trauma and that lingering symptoms result from other problems such as post-traumatic stress disorder. But this study suggests these veterans suffer significant neurological damage.

"This is evidence of persistent alterations of the brain of Iraq and Afghanistan veterans with repetitive blast exposure," said Elaine Peskind, a Veterans Affairs Puget Health Sound Health System psychiatrist who led a team of 11 VA and University of Washington researchers. "These changes are real and long lasting."

Peskind says the results of the brain imaging also raise concerns that some blast-exposed veterans, in their mid-to-later years, will suffer from higher rates of Alzheimer's or other forms of dementia that afflict some professional boxers and football players.

Co-author Donna Cross, of the University of Washington, who worked on the imaging with Eric Petrie and Satoshi Minoshima, recently received an award for the research from the Society of Nuclear Medicine.

Different results

The study is at odds with published findings of Charles Hoge, an influential researcher in military medicine who is convinced that thousands of U.S. military personnel have been misdiagnosed with mild traumatic brain injury.

Hoge, who works in the office of the Army's Surgeon General, says these men and women are more likely to suffer from depression or post-traumatic stress disorder that is largely unrelated to exposure to concussive blasts.

Many of these blasts result from roadside bombs that have been a weapon of choice for insurgents in both Iraq and Afghanistan. These blasts send shock waves that penetrate the skull.

In 2008, the Army began screening all returning soldiers for signs of mild traumatic brain injury.

Hoge notes big differences between major concussions that render a soldier unconscious for 30 minutes or more, and minor events that don't cause long-lasting symptoms.

He questions the way the Army screens for mild traumatic brain injury, as well as a federal regulation that enables the VA to assign a 40 percent disability rating — and offer compensation payments — to veterans who have at least three symptoms of such an injury.

"Devoting increasingly more personnel and time to the illusory demands of mild TBI (traumatic brain injury) could hinder service members' and veterans' recovery," Hoge wrote in an April 2009 article that he co-authored in the New England Journal of Medicine.

A deeper look

Even the name of the diagnosis — mild traumatic brain injury — has created controversy. Some medical personnel believe it's a label that can unfairly stigmatize a soldier who suffered minor concussions.

Others say the injury has been ignored too often.

The military says some 150,000 cases of mild traumatic brain injury have been diagnosed among troops since the onset of the Afghanistan and Iraq wars. A recent investigation by National Public Radio and ProPublica found that tens of thousands more troops with this injury have not been diagnosed and that troops sometimes have had to battle for appropriate treatment.

Peskind says the symptoms of these veterans should not be discounted and believes the Army needs to step up research into the effects of explosive shock waves.

Peskind first became concerned about blast effects in 2005 as she counseled young soldiers returning from the war. Many patients carried notebooks and constantly took notes to remember what she had said.

"That may be normal in the elderly but not someone who is 19 years old," Peskind said. "So a light bulb went off in my head that this is a problem."

Peskind and her colleagues launched their study with 12 veterans who had been subjected to shock waves from an average of 14 blasts in Iraq. They retained consciousness through most of the blasts, but many briefly lost consciousness in stronger explosions.

"We were mortared quite frequently, and I was knocked out once when my vehicle was hit," said Jeff Biberston, a Marine veteran of two tours of duty in Iraq and a third to the Afghanistan-Pakistan border region who volunteered to participate in the study.

Many veterans exposed to blasts don't have long-term symptoms.

But the dozen veterans included in the initial study group suffered from problems years after their exposure.

A few, such as Biberston, had minor issues with hearing loss and memory. Most suffered from a range of symptoms including short-term memory loss, irritability, attention deficit and headaches, and had dual diagnosis of mild traumatic brain injury and post-traumatic stress disorder.

To conduct their research, Peskind and her research team turned to Positron Emission Tomography, or PET, scans that inject subjects with a minute dose of radioactive glucose, then track the rate the sugar is metabolized by the brain.

Glucose is an energy source for the brain. Use of the sugar is a marker for brain activity.

In scans of 12 veterans cited in the NeuroImage article, the researchers found four areas of the brain utilized the glucose at substantially below the rates of other study volunteers who never had served in the military. The affected brain areas are involved in regulating emotion, language, mental focus, sleep and other key functions.

Since the article, Peskind's team has tested nine more blast-exposed veterans, and their results have tracked those of the early subjects.

In a new phase of research, Peskind's team is examining the brains of these veterans with a specialized form of magnetic resonance imaging or MRI. This research indicates the blasts also may have caused structural abnormalities to the brain, and researchers are looking for additional evidence that these veterans are at higher risk of dementia.

"Some people have said this is all going to go away," Peskind said. "But it hasn't gone away. My big concern is what will happen to these veterans in the future."

Hal Bernton: 206-464-2581 or

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