By Brenda L. Mooney

BOSTON — Compelling evidence that a degenerative brain condition can be caused by a single blast, equivalent to a typical improvised explosive device (IED), raises troubling questions about the future healthcare needs of servicemembers returning from Iraq and Afghanistan.

Tactical Explosive Detection Dogs stand with their handlers April 29 after their long- awaited arrival to Forward Operating Base Pasab. The dogs provide early detection and warning to paratroopers of explosive materials, such as improvised explosive devices (IED). All handlers are 4th Brigade Combat Team paratroopers and, for the majority of them, this is their first deployment. Photo by Capt. Allie Scott.

The new study found indications in brain tissue from blast-exposed military personnel of chronic traumatic encephalopathy (CTE), an Alzheimer’s disease-like condition that has been diagnosed primarily in athletes with repetitive head injuries.¹

The study also noted that as much as 20% of the 2.3 million troops deployed to Iraq and Afghanistan since 2001 could have suffered a traumatic brain injury (TBI) as a result of exposure to IEDs. In a worst-case scenario, 460,000 veterans could be at risk for CTE.

The investigators from Boston University and the VA Boston Healthcare System also demonstrated in laboratory experiments that it was the blast wind, not the shock wave, from the IED that resulted in the initial traumatic brain injury  and the cognitive effects.

"The neuropsychiatric symptoms of CTE that have previously been associated with athletes diagnosed with CTE could also be attributed to military personnel who were exposed to blasts," senior co-author Lee Goldstein, MD, PhD, associate professor at Boston University School of Medicine and Boston University College of Engineering, said in a statement.

Ann McKee, MD, conducts post-mortem brain exams at the Bedford VA Medical Center. -Photo by Kristin Pressly

The other senior co-author was Ann McKee, MD, a Boston University School of Medicine professor and director of the Neuropathology Service for VA New England Healthcare System.

Goldstein and McKee’s research was published online last month by the journal Science Translational Medicine.

CTE is a progressive degenerative disease that causes erratic behavior, memory impairment, depression and problems with impulse control. Eventually the symptoms may progress to full-blown dementia. Onset of CTE symptoms tends to be earlier than those for Alzheimer’s disease, although it can be several years — even decades — after the original head trauma for the symptoms to first appear.