Brain Trauma in Iraq

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After the Blast: Stephen Kinney, a U.S. National Guard sergeant, survived a roadside blast while serving in Iraq in 2004. After he returned home, his mild traumatic brain injury went undiagnosed for months. Credit: Christopher Churchill

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Reporter's Notebook: Emily Singer

A few days into his tour of duty at the 86th Combat Support Hospital in Baghdad, Colonel Geoffrey Ling, a U.S. Army neurologist, noticed something unusual. Soldiers who had sustained severe head injuries in blasts from improvised explosive devices (IEDs) appeared to be in much worse shape than he would have expected given his experience with patients who had suffered seemingly similar injuries in car accidents and assaults. The brains of the injured soldiers were swollen and appeared "a very angry red," he recalls. Some soldiers were conscious and could talk normally but were stumbling around the hospital, unable to keep their balance. "Their [brain] scans were stone-cold normal, and when you talked to them, they seemed fine," says Ling, who is now a staff physician at Walter Reed Army Medical Center and a program manager in the Defense Sciences Office at the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, VA. "But when I started testing them, like asking them to do addition, they were clearly not normal."

By the time Ling arrived in Iraq, in 2005, thousands of U.S. soldiers had experienced IED attacks. While many of them had survived the concussive blasts, Ling and other physicians had begun to notice that a worrisome number were showing signs of brain damage. Ling, who is a neuroscientist as well as a neurologist, was puzzled. "Why does this injury look different?" he wondered. "What is it in the blast that's causing it--the pressure, the noise, the cloud of fume?" After months of treating blast wounds in both American troops and Iraqi security forces, Ling had returned from his tour determined to wage war on brain injury. He knew that the answers to these questions could be crucial to protecting soldiers in the field and screening and treating them when they came home.

Traumatic brain injury has been called the signature injury of the Iraq War, in which increasingly powerful IEDs and rocket-­propelled grenades are the insurgents' weapons of choice. Because they produce such powerful blasts, these weapons often cause brain injuries. Meanwhile, thanks to better body armor and rapid access to medical care, many soldiers whose injuries would have been fatal in previous wars are returning alive--but with head trauma. "With IEDs, the insurgents have by dumb luck developed a weapon system that targets our medical weakness: treating brain injury," says Kevin "Kit" Parker, a U.S. Army Reserve captain and assistant professor of biomedical engineering at Harvard University who served in southern Afghanistan in 2002. Doctors do not yet fully understand brain injuries, particularly those caused by blasts, and no effective drug treatments exist. Early evidence suggests that explosions, which account for nearly 80 percent of the brain injuries identified at Walter Reed, cause unique and potentially long-lasting damage.

The extent and impact of the brain-injury epidemic are not yet clear, though the U.S. Congress appropriated $300 million last year for research into traumatic brain injury and post-­traumatic stress disorder. The U.S. Department of Defense reports that approximately 30 percent of those evacuated from the battlefield to ­Walter Reed Army Medical Center have traumatic brain injury (TBI). The problem is probably worse than that: the DOD figure does not include brain injuries in soldiers whose wounds were not severe enough to require evacuation or whose injuries were not identified until after they completed their tours. Post-deployment surveys suggest that 10 to 20 percent of all deployed troops have experienced concussions. At worst, thousands of service members could return home with long-lasting problems, ranging from debilitating cognitive deficits to severe headaches and depression to subtler personality changes and memory deficits.

Military doctors are only beginning to get a grasp on the number of soldiers who have suffered mild traumatic brain injury, the medical term for a concussion. Mild injuries are by far the most common type of brain trauma, but they are more easily missed than moderate and severe injuries (they typically don't show up on standard brain scans), and the lasting effects, especially of repeated concussions, are not yet clear. Surveys of troops to be redeployed in Iraq suggest that 20 to 40 percent still had symptoms of past concussions, including headaches, sleep problems, depression, and memory difficulties. "We don't know what it means in terms of long-term functional ability," says William Perry, past president of the National Academy of Neuropsychology.