FORT CAMPBELL, Ky. -- Before they leave for Iraq, thousands of troops with the 101st Airborne Division line up at laptop computers to take a test:~ Brain injuries caused by explosions have become some of the most common combat wounds suffered in Iraq.
basic math, matching numbers and symbols, and identifying patterns. They press a button quickly to measure response time.
It's all part of a fledgling Army program that records how soldiers' brains work when healthy, giving doctors baseline data to help diagnose and treat them if they come back with a traumatic brain injury -- the signature injury of the Iraq war.
"This allows the Army to be much more proactive," said Lt. Col. Mark McGrail, division surgeon for the 101st. "We don't want to wait until the soldier is getting out of the Army to say, 'But I've had these symptoms.'"
The mandatory brain-function tests are starting with the 101st at Fort Campbell and are expected to spread to other military bases in the next couple of months. Commanders at each base will decide whether to adopt the program.
The tests provide a standard, objective measurement for each soldier's reaction time, their short-term memory and other cognitive skills. That data would be used when the soldiers come home to identify mild brain trauma that can often go unnoticed and untreated.
One veterans group wants to ensure the Army doesn't use the results to deny treatment by claiming that soldiers' problems came from pre-existing conditions.
"We certainly think these tests should not be used to reduce the responsibility that the Army has to treat the soldiers who have served," said Jason Forrester, director of policy for Veterans for America.
About 7,500 Fort Campbell soldiers have completed the tests, said Dr. Robert Schlegel, a University of Oklahoma researcher who administers the 10-minute exams to soldiers as they file quickly through a testing center.
One question asks soldiers to memorize patterns on the screen and then identify them later among several different patterns. Other questions require soldiers to match numbers and symbols, or complete simple addition and subtraction problems.
"Everybody functions a bit differently in terms of how quickly they react to things, how well they process things and remember things and so forth," Schlegel said.
Brain injuries caused by explosions have become some of the most common combat wounds suffered in Iraq. Thirty percent of soldiers taken to Walter Reed Army Medical Center since 2003 suffered traumatic brain injuries, according to the Defense and Veterans Brain Injury Center.
The brain-injury center, which has seven facilities around the country, has seen 2,669 patients between 2003 and 2007. But doctors believe many less obvious brain-injury cases go undetected.
Soldiers sometimes walk away from explosions with no obvious injuries. But the concussion from the blast can have a lingering effect that is not always immediately apparent.
"They look physically normal, but their neurocognitive performance is off," said Col. Mary Lopez, a physician specializing in occupational therapy.
Most brain injuries are mild, and soldiers can recover with rest and time away from the battlefield. But the military estimates that one-fifth of the troops with these mild injuries will have prolonged or lifelong symptoms requiring continuing care.
So little is known about traumatic brain injuries that these baseline readings could become an important cornerstone for future study.
Even the parameters of the injury are not known, like how close a soldier must be to a blast to suffer damage, or whether being knocked unconscious makes a difference, said Jordan Grafman, a neuroscience researcher at the National Institutes of Health. Without baseline information, it is hard to say soldiers are more impaired after they suffer a serious brain injury.
The Army has faced criticism for treatment of Iraqi war veterans after complaints that some soldiers with brain damage were misdiagnosed. The Government Accountability Office is investigating reports that as many as 40 soldiers at Colorado's Fort Carson were misdiagnosed with personality disorders after suffering brain damage or stress-related injuries.
Lt. Col. Mark McGrail, division surgeon for the 101st, said mild brain injury is difficult to diagnose because soldiers often don't report symptoms such as headaches, dizziness, memory problems and irritability.
"The soldiers are by and large very motivated, and they don't want their team to go back out there without them, even though they know they had their bell rung and might not be at the top of their game," McGrail said.
Some symptoms of traumatic brain injury also overlap with post-traumatic stress disorder, another common condition among Iraq war veterans. The brain-injury test could also help doctors differentiate between those conditions, Lopez said.
The brain tests have already been tried in pilot programs at Fort Bragg, N.C., with paratroopers who often suffer concussions during jumps, as well as with some soldiers who have deployed to Iraq, Afghanistan and Bosnia.
But the 101st is the first unit to use them on a large scale for every soldier preparing to deploy. The division is leaving for its third deployment, splitting between battlefronts in Iraq and Afghanistan.