Tuesday, September 23, 2008

Part II: Brain Trauma in Iraq

Soldiers with traumatic brain injuries face an uncertain future.
By Emily Singer

Mixed Signals
On May 20, 2004, Jerry Pendergrass's convoy was ambushed. The National Guard sergeant was standing outside his Humvee when a rocket-propelled grenade landed a few feet behind him and exploded, launching him 15 feet in the air. A few moments later, Pendergrass found himself lying on the ground, shrapnel lodged in his leg and his helmet several yards away. He was conscious but unsure of where he was, classic signs of concussion. Another member of his unit pulled him behind the protective barrier of the disabled Humvee, where they awaited evacuation to a medical checkpoint in a secure zone down the road.

Pendergrass soon returned to duty, ignoring the persistent headaches and the sleep, memory, and balance problems that plagued him after the blast. When his tour was up and he returned home to North Carolina, he took prescription painkillers and drank, trying to wash away both his memories of war and the reality of his health problems. It wasn't until he began a second tour--and was evacuated two months later for spinal damage linked to the earlier blast--that he realized the full extent of his injuries. He was diagnosed with both mild traumatic brain injury and post-traumatic stress disorder (PTSD)--a condition, first defined in Vietnam veterans, that can develop after exposure to a terrifying event. "Big bangs scare the living fart out of me," says Pendergrass, in a conference room at the Lakeview Virginia NeuroCare center in Charlottesville, VA. He seems startled by even small noises, jumping as a nearby copy machine is jostled into action.

Pendergrass has spent the last three months at NeuroCare, which is partnered with the Defense and Veterans Brain Injury Center. The small in-patient clinic, with an adjacent residence for patients, offers intensive therapy and is staffed by occupational and physical therapists, speech and language therapists, and clinical psychologists. Pendergrass is getting psychological counseling for PTSD and rehabilitation for his brain injury.

He expects to return home soon, but his recovery is complicated by his dual diagnosis. In blast-injured soldiers, PTSD and mild brain injury often occur together. The two conditions also share symptoms--including depression, memory and attention deficits, sleep problems, and emotional disturbances--and research suggests that they can aggravate each other. A 1998 study of veterans with PTSD found that those exposed to blasts were more likely to have lingering attention deficits and abnormal brain activity that persisted long after the injury. And a study published earlier this year in the New England Journal of Medicine found that the 15 percent of soldiers who reported having suffered concussions had a much greater risk of developing PTSD: 44 percent of soldiers who had lost consciousness on the battlefield met criteria for PTSD, compared with 16 percent of those in the same brigades who suffered other injuries.

However, the two conditions can have different prognoses. While PTSD is a serious anxiety disorder, it can often be treated effectively with psychological and drug therapies. Patients with moderate to severe TBI have a far grimmer prognosis. Even ­people with concussions, who often get better on their own, can have enduring damage: symptoms that linger more than six months may be permanent. No drug treatments have proved effective for curing long-term symptoms, and other therapies are limited. For the most part, patients are simply taught new strategies for dealing with their impairments, such as carrying notepads to help them remember important tasks or designating specific spots for their keys.

Determining the true extent of the Iraq War's brain-injury epidemic will require sorting out whether individual patients' persistent symptoms are caused pri­marily by PTSD or by physical trauma. Statistical analysis from the New England Journal of Medicine study found that lasting symptoms could be attributed largely to PTSD and depression rather than to brain injuries themselves. But the conclusion is controversial. "I think that's minimizing the potential effects of concussion in this equation," says Barth, the University of Virginia neuropsychologist.

The debate over whether the mental wounds of war are biological or psychological has recurred in one form or another in every major war of the last century, ever since powerful explosives became widespread on the battlefield. During World War I, military doctors coined the term "shell shock" to describe the plight of soldiers who stumbled into army hospitals afflicted by dizziness and confusion, uncontrollable twitching, or an inability to speak. At first, doctors attributed the symptoms to brain damage caused by the frequent explosions that characterized the new trench warfare. But as soldiers who had never been exposed to blasts began reporting similar complaints, military psychiatrists started to suspect a sort of ­combat-­triggered hysteria. A labeling system used by the British army at the time suggests the difficulty of distinguishing between the two problems (and the moral opprobrium attached to those whose condition was deemed psychological). Victims were designated either "shell-shock wounded," meaning the symptoms arose after the soldier was shelled, or "shell-shock sick," meaning the symptoms were not linked directly to an explosion. Only those with "wounded" status were awarded pensions and granted the honor of wearing "wound stripes" on their uniforms.

Walter Reed's David Moore hopes that new imaging technologies will finally resolve the debate by identifying the subtle neurological damage inflicted by concussion. One promising technology is diffusion tensor imaging (DTI), a variation on traditional magnetic resonance imaging (MRI) that highlights white matter, the long nerve fibers connecting brain cells. Recent studies of people with mild traumatic brain injury (from car accidents, for example) suggest that changes in the organization of the brain's white matter correlate with patients' cognitive deficits. Preliminary evidence suggests that patients who show the greatest disruption of white matter early on also have the poorest outcomes.

In a large, ongoing study at Walter Reed, which Moore is overseeing, researchers will use DTI to compare returning soldiers who have experienced blasts and report the hallmarks of concussion--loss of consciousness or situational awareness--with a military control group reporting no previous brain injuries. The scientists hope the images will help them identify specific brain changes linked to concussion, which will make it easier to diagnose the injury and predict its outcome.

Three years after Geoffrey Ling's time in Iraq, his war on brain injury has really just begun. Scientists have preliminary evidence that forces unique to blasts can damage the brain directly, independent of any blunt injuries that the blast might also cause. The key questions, however, remain unanswered. Which aspects of the blast do the most damage? How can the military better protect its personnel? And perhaps most important for legions of soldiers on patrol, can repeated exposure to weak blasts lead to long-­lasting brain damage?

The prognosis for soldiers returning home with symptoms of brain damage is not encouraging. Decades of research into ­civilian head trauma have come to very little; treatments that seemed promising in animal models have turned out to be ineffective in human tests. "It's a completely untapped area of medical development," says trauma surgeon Jon Bowersox. While the military is testing a handful of existing drugs, there's a "time mismatch" when it comes to developing new treatments specifically for traumatic brain injury, Bowersox observes. "The military is interested in developing products they can have out during the current war," he says. "They are not used to the fact that medical development has a longer time line."

Even the few therapies that do exist will be difficult to deliver to everyone who needs them. "What will we do with all these people?" asks Barth. "We're talking about thousands. This is going to overwhelm the VA hospitals." The military is preparing some of those hospitals to better deal with brain injury, hiring neuro­psychologists to make diagnoses and other experts to run rehabilitation programs. But resources are limited. At some of the medical centers, "physicians haven't had any training in rehabilitation other than clinical medicine," says Bowersox.

Perhaps the greatest challenge will be to help injured soldiers resume their previous lives. "Young people are not equipped emotionally and financially to handle this," says Marilyn Price ­Spivack, founder of the Brain Injury Association of Massachusetts, which has recently begun an outreach effort aimed at veterans. "Often they can't go back to their civilian jobs and are very hard to employ."

The goal of facilities like NeuroCare is to return people to service or to their civilian jobs. But even a quick visit with some of the patients shows what a long road that will be for many of them. In the clinic, one patient apologizes as he twitches uncontrollably. Another abruptly leaves the room, suddenly overcome with anxiety. And ­Pendergrass, who has had serious balance problems since he was injured, is unlikely to be able to return to his previous job hanging power lines. He doesn't yet know what he'll do when he leaves the rehab center.

Emily Singer is TR's biotechnology and life Sciences editor.

1 comment:

Stephen said...

I dislike any type of medical issues that have to due with the brain. It seems like that's one field that doctors just don't know too much about. I was talking with a friend that happens to be a Los Angeles brain injury lawyer and they told me that more brain injuries are caused by doctors that any other type of accident. It's a pity.