The signature wound of the wars in Iraq and Afghanistan — mild traumatic brain injury, or TBI — is hard to diagnose and just as difficult to treat. Now, many of these injured soldiers are returning to duty, and doctors are struggling to determine whether and when they're well enough to fight.
One way to find out is to observe patients under the stress of combat in simulated battlefield situations. That's what physicians at Fort Campbell in Kentucky are doing with recovering TBI patients.
On The (Mock) Battlefield
"Jesus!" says Sgt. Joshua Thurman, as an explosion catches him by surprise. He and a team of recovering TBI patients at Fort Campbell sweep a gravel road for possible roadside bombs. They're armed with paintball guns, taking periodic fire from pretend insurgents.
The last time most of these veterans heard bomb blasts and gunshots was the day they nearly died in Afghanistan.
"Manning the .50 cal, there was an explosion, concussion got me," Thurman says. "Came to find out I did have a TBI, but I also lost the hearing in my left ear."
Many of these soldiers now wear hearing aids. That limitation alone may keep some from going back to the front line. The lingering effects of the concussion also get in the way. Memory loss, mood swings and balance problems make returning to duty after a traumatic brain injury difficult, but not impossible.
Physical therapist Tamara Moreland tests the balance of TBI patients after each battlefield simulation.
She asks one soldier, Sgt. Patrick Cummings, to shake his head. Then she instructs others to take 50 steps in place with their arms straight out and their eyes closed.
Moreland watches to see if they end up in the same place they started. Physical symptoms of TBI tend to get worse under stress, and Moreland wants to see how much worse.
Returning To Duty
Until now, returning to duty took a doctor like David Twillie looking at a few charts and signing off. That's changing.
"Soldiers are making life and death decisions, so doesn't it make sense to use demonstrated competence as the standard for returning someone to duty?" he asks.
Twillie directs Fort Campbell's TBI clinic, which has been singled out as a national model by the Pentagon. Here patients must demonstrate their competence through pencil-and-paper tests as well as new real-life exercises.
Most soldiers who get to these simulations will return to duty, Twillie says. But some soldiers appear ready to go back on paper, when they're really not.
"In fact very recently we had a soldier that had a desire to stay in, had done well in all our simulations," Twillie says. "But when all the different sights, sounds, smells came back, he just wasn't able to change his focus, and that's very important in combat."
A Flashback, And Tears
Jeremy Cole, a trainer who works with the TBI patients, tries to see whether soldiers can complete a series of tasks in the correct order even when rattled. He plays audio from a battlefield scene in Saving Private Ryan and then tells the soldiers to put in chest tubes and tighten down tourniquets.
"Catch your breath," he tells one soldier who is trying to assess a casualty.
As the sound goes down and the lights come up, pools of red surround each body.
"I've had soldiers' blood on my hand before, so it takes you back there," says Staff Sgt. Nicholas Smith, looking at his own hands.
He says the amount of blood in this simulation is pretty true to life.
"The only difference is no one's screaming 'Mom!' or 'Get me out of here!' That's the only difference."
Sgt. Patrick Cummings, a big guy with a serious face, says he's surprised by his reaction to the battlefield simulations.
"It kind of brought tears because I was there. I was one of these patients before," he says. "It just hit home."
Despite the flashback, Cummings wants to deploy again. As a TBI survivor, he won't be alone. The Department of Defense estimates roughly 115,000 soldiers have experienced one of these mind-altering injuries.