In honor of Veterans Day,Technology Review is again highlighting some recent advances in understanding traumatic brain injury--a central issue for many of the troops returning from Iraq and Afghanistan. We first highlighted this problem in a feature in 2007, Brain Trauma in Iraq.

This year, David Moore, a neurologist highlighted in the feature, showed that diffusion tensor imaging, a brain imaging technology, could distinguish between blast-related injuries and other sources of concussion.

According to a recent story of ours:

The blasts caused by improvised explosive devices in Iraq and Afghanistan appear to inflict a fundamentally different type of brain damage than do more traditional sources of concussions, such as blunt trauma. The findings point toward new approaches to diagnosing and monitoring these injuries, which have been a huge concern to the military in recent years. The research also begins to resolve a controversy in brain-injury research--whether soldiers who are near an explosion but don't get hit in the head can still suffer a unique type of brain damage.

Regular concussions are typically caused by direct impact to the head, such as in a fall, or acceleration injuries, as in car accidents. In contrast, blast-induced brain injuries can include both of these factors as well as one that is unique to explosions--a rapid pressure wave that may wreak its own havoc on the brain. As a growing number of troops return from Iraq and Afghanistan with signs of brain injury--post-deployment surveys suggest that 10 to 20 percent of all deployed troops have experienced concussions--the military has been under increasing pressure to understand how this pressure wave affects the brain, as well as how best to diagnose and treat the resulting injuries.

Typically, damage from concussions does not show up on traditional medical imaging tests, such as CT scans or MRIs. But scientists have recently begun using a variation of MRI known as diffusion tensor imaging (DTI) to detect damage to the brain's white matter--the neural wiring that connects cells--after mild traumatic brain injury.

In the new study, David Moore, a neurologist and deputy director for research at the Defense and Veterans Brain Injury Center in Washington, D.C., and colleagues used DTI to assess troops who had been diagnosed with mild traumatic brain injury following a blast, a direct impact, or an acceleration-induced injury several months prior, as well as healthy people who had never suffered a concussion. They found that those with blast-linked trauma had a more diffuse pattern of damage to the white matter, described as a "pepper-spray pattern," than those whose concussions were caused by direct impact or acceleration. The research was presented at the World Congress for Brain Mapping and Image Guided Therapy conference in Boston last month.

Researchers are also pushing forward a blood test to assess more severe brain injuries. According to the piece,

One blood test already used in Europe to screen head-trauma patients before CT scans detects a protein called S100B, which is released by astrocyte cells in the brain after injury. "The thinking is, if you don't have [this marker] in the blood, then you don't have the kind of brain injury you could see on CAT scan," says Jeffrey Bazarian, an emergency-room physician and scientist at the University of Rochester Medical Center, in New York. The test is not approved for use in the United States, however. In a set of clinical guidelines for evaluating head trauma published recently, Bazarian and others estimated that the S100B test could significantly reduce unnecessary CT scanning. "We predict it could eliminate unnecessary radiation in a lot of people--about 30 percent [of those who come into the ER with brain injury]," he says.

Twenty active and retired members of the U.S. military have agreed to donate their brains upon death to a research project dedicated to understanding the effects of repetitive head trauma.

The program, a collaboration between the Sports Legacy Institute, a nonprofit organization based in Waltham, MA, and the Boston University Center for the Study of Traumatic Encephalopathy, has so far focused on professional athletes, garnering pledges from football players such as Ted Johnson to donate their brains for research. Johnson, a former Patriots player, says that he has suffered neurological problems that he believes are linked to multiple concussions sustained during play. According to the Sports Legacy Institute, "10 of 10 brains of deceased contact sport athletes, ranging in age of death from 18-80, have shown some degree of evidence of chronic traumatic encephalopathy," also called dementia pugilistica, a neurological disease first identified in boxers that is linked to cognitive decline.

Troops serving in Iraq and Afghanistan may also face risks of long-term brain damage. With the increasing use of improvised explosive devices (IEDs), many have suffered concussions or more severe head trauma. In March of 2009, the Department of Defense estimated that troops in Iraq and Afghanistan have suffered more than 360,000 brain injuries, and 45,000 to 90,000 suffer ongoing symptoms. TR explored this issue in a feature published in the May 2008 issue, "Brain Trauma in Iraq."

According to an article in the New York Times,

Repeated brain trauma among some football players and boxers has been linked to the subsequent appearance of toxic proteins and neurofibrillary tangles in the brain--a disease known as chronic traumatic encephalopathy, or C.T.E. Many athletes who were found after death to have had the disease experienced memory loss, depression and oncoming dementia as early as their 30s, decades before afflictions like Alzheimer's appear in the general population.

The Boston University center and the Sports Legacy Institute will compare findings from the brains of military personnel with those from their athlete program, which has signed up more than 120 donors in less than a year, and other brain banks around the world. The two centers, not the military, are paying for the registry, storage, and examination of brain tissue.

The Sports Legacy Institute says,

The program is expected to mirror the SLI athlete registry . . . The initial registry members were twelve current and former professional athletes, including former NFL star Ted Johnson and current NHL player Noah Welch. The registry has since grown to 130 members, 80 professional and 50 amateur, as of June, 2009.