FORT CAMPBELL, Ky. – Motivated by the deaths of two friends in war-zone explosions, 1st Lt. Timothy Dwyer decided to become a bomb hunter.
By joining an explosive ordnance disposal unit, Dwyer put himself at a high risk not just of being killed, but of falling victim to another, more insidious threat: repeated concussions from blasts that don't kill.
Soldiers from the Army's 52nd Ordnance Group based at Fort Campbell have undergone hours of exhaustive cognitive testing in the military's first-of-its-kind study of mild traumatic brain injury. This focus on the soldiers who find and destroy the powerful and deadly weapons is part of a larger effort by the military this year to better track and treat mild brain injuries.
The Fort Campbell bomb specialists will be tracked during their upcoming Afghanistan deployment for concussions and head injuries to look for effects on brain functions.
"No one wants to get hurt, but being a soldier, being (in explosive ordnance disposal), it's just one of those things you've come to expect that might happen to you," said Dwyer, a 23-year-old platoon leader with three kids who is leaving this year for his first deployment.
The nature of the ordnance group's work makes its members the ideal patients for the study of mild brain injuries, said Dr. Bret Logan, deputy commander for managed care and compliance at Blanchfield Army Community Hospital at Fort Campbell.
"We tried to identify those populations that we could have almost an assured likelihood that they would have a concussive episode," Logan said.
Active in high school sports, Dwyer said he'd had at least three diagnosed concussions before joining the Army. In addition to those, Dwyer admitted, "I've had a lot of concussions that I have never gone to the doctor for."
During the testing, the soldiers are subjected to numerous mental exercises and given puzzles and quizzes that give a baseline of a soldier's brain functions before an injury. One test required Dwyer to quickly press a series of blinking lights while doing math problems in his head. In another, he was asked to recall a list of words that he was given earlier.
Dr. Tamara Moreland, a physical therapist at the Traumatic Brain Injury Center at Fort Campbell, instructed Dwyer to stand on a platform that shifted and rocked under him. The test measured how well his inner ear works to keep his balance, an area of common injury after explosions.
In a small office at the post's center, another EOD officer, 1st Lt. Jay Park, was fitted with what looked like a swim cap with electrodes jutting out and clips on his ears. Cotton balls taped over his eyes reduced eye movement during the testing, and wires from the cap plugged into a computer that measured activity in different parts of his brain.
The Department of Defense says 178,000 troops have been diagnosed with traumatic brain injuries since 2000, mostly mild cases. Even those can have wide-ranging effects on concentration, speech, balance and eyesight.
The Army released new rules this year for soldiers who are within 50 meters of a blast, are in a vehicle that rolls over or are in a vehicle involved in a blast. Those soldiers now must undergo a medical evaluation and be put on 24 hours of rest before returning to duty. Comprehensive evaluations will be mandatory after three concussions in one year.
Studies have shown that a person can fully recover after a concussion, but another concussion without time to rest can impair healing.
"The brain is using a lot of energy to heal, and if you stress the brain so that it runs out of energy, it's actually going to cause death of neurons," said Dr. David Twillie, director of Fort Campbell's Traumatic Brain Injury Center.
Twillie said he understands that some soldiers will not want to take a break from the fighting after a concussion, but he said the rest will keep more soldiers ready for battle.
"You can actually conserve the fighting strength by having a soldier take a knee versus breaking the soldier to the point where they won't be able to return," he said.