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

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SEATTLESeattle 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.

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.

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 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 AfghanistanPakistan 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 Postiron 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.”

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