Evaluating military personnel with blast-related mild traumatic brain injuries, researchers have found that early symptoms of post-traumatic stress, such as anxiety, emotional numbness, flashbacks and irritability, are the strongest predictors of later disability.
The results were surprising because mental health more closely correlated with disability than assessments typically made after concussions, such as tests of memory, thinking, balance, coordination and severity of headaches and dizziness, according to the study led by Washington University School of Medicine in St. Louis.
“Symptoms of post-traumatic stress and depression have always been thought to develop months to years later,” said David L. Brody, MD, PhD, associate professor of neurology at Washington University. “We don’t know what causes these symptoms, whether they result from the brain injury itself, from the stress of war or some combination of factors. But regardless of their origin, the severity of these psychological symptoms soon after injury was the strongest predictor of later disability.”
Appearing in the journal Brain, the study also suggests that mild concussions have more severe long-term effects than previously thought, including difficulty returning to previous work, family and social activities. The results raise questions about how best to treat U.S. troops who suffer head injuries.
During the conflicts in Iraq and Afghanistan, about one-fifth of service members experienced a head injury, according to recent estimates from the U.S. Department of Defense, and more than 80 percent of those were considered mild.
“I was surprised by how severe the level of disability was 6-12 months after these seemingly mild injuries, especially given that virtually all of these patients returned to duty soon after their concussions,” said Brody, the study’s senior author.
According to the investigators, the study is the first to evaluate active-duty service members with blast-related mild concussions very early, in the first week after injury, and to combine that with follow-up evaluations of the same patients 6-12 months later. Most studies of traumatic brain injury in military personnel have focused on those injured severely enough to be evacuated from war zones.
This work was supported by the Congressionally Directed Medical Research Program, grant number PT090444.
MacDonald CL, Adam OR, Johnson AM, Nelson EC, Werner NJ, Rivet DJ, Brody DL. Acute post-traumatic stress symptoms and age predict outcome in military blast concussion. Brain. March 4, 2015.