The findings build on a growing number of clues illuminating blast-related brain injury. By studying Marines being trained to set controlled explosions, as well as pigs exposed to explosions, Geoffrey Ling, a neurologist and scientist at the Defense Advanced Research Projects Agency, and colleagues found signs of brain inflammation in the blood, even when no other signs of injury were present.
“We are starting to understand the mechanisms of the blast, and that’s leading us to ask different questions,” says Michael Jaffee, national director of the Defense and Veterans Brain Injury Center. For example, scientists now want to better clarify the role of inflammation in this type of injury. DTI might also prove useful for diagnosing blast-related concussions and assessing recovery, he says. Because symptoms of mild traumatic brain injury can resemble posttraumatic stress disorder, an anxiety disorder, it can be difficult to distinguish the two.
While DTI is promising as a new diagnostic technology, Moore emphasizes that additional alternatives are still sorely in need. About 80 percent of the brain injury patients eligible for the study at Walter Reed Army Hospital had to be excluded because of metal shrapnel in their bodies. (MRI machines generate a strong magnetic field, making it dangerous for people with metal implants or shrapnel.)