Early symptoms related to post-traumatic stress such as anxiety, emotional numbness, irritability, and flashbacks are the strongest predictors of later disability for military members effected by blast-related mild traumatic brain injuries according to a new report published in the journal Brain.
Researchers from the Washington University School of Medicine in St. Louis did not expect the result of the study, but the findings show mental health issues were more closely linked with later disability than cognitive and physical assessments commonly used after brain injuries.
“Symptoms of post-traumatic stress and depression have always been thought to develop months to years later,” said David L. Brody, M.D., Ph.D., associate professor of neurology.
“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.”
The findings lead the researchers to believe mild concussions may have more significant and severe long-term effects than previously believed, including difficulty returning to work, family, and social activities.
Traumatic brain injuries are often called the signature injury of the wars in Afghanistan and Iraq, where nearly one-fifth of service members reported brain injuries. Approximately 80 percent of these head injuries were deemed to be ‘mild’.
“I was surprised by how severe the level of disability was six to 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.
The team of researchers say this is the first study to pro-actively assess active-duty service members with blast-related mild concussions in the time immediately after brain injuries. Participants were evaluated in the week following their injury, and then again six to twelve months later. Most military studies on brain injuries have relied almost exclusively on veterans injured severely enough to be evacuated from war zones.
For the purpose of this study, the researchers at Washington University and the Naval Medical Center Portsmouth in Virginia evaluated traumatic brain injury from blast exposure in active-duty service members stationed in Afghanistan in 2012.
The study included 38 patients diagnosed with mild blast-related brain injury and 34 service members without brain injury who volunteered to serve as controls. Those in the study ranged in age from 19-44, with a median age of 26 in the study group and 28 in the control group.
Initial assessments of service members included in the study were made in Afghanistan in the first week following injury using a standard military questionnaire for assessing symptoms of post-traumatic stress disorder.
The questionnaire surveyed injured service members on if they experienced repeated disturbing memories or dreams, feelings of emotional numbness, difficulty concentrating, or feelings of anger or hyper-alertness.
At the time of follow-up evaluations, 63 percent of the individuals in the brain injury group were classified as moderately disabled, while only 20 percent of the control group were classified similarly.
To be deemed moderately disabled, service members had to exhibit being unable to work as they did before injury, unable to continue previous social and leisure activities, or mental health issues which disrupt relationships with friends and family.
“When we were able to connect the dots, we saw that injuries that might have been considered trivial seemed to have a big impact on how these patients did later on,” said first author Christine L. MacDonald, Ph.D.
The findings went against the expectations of the researchers because the large majority of previous research on traumatic brain injury in military members and civilians primarily focused on cognitive function and physical symptoms such as headaches or nausea.
“Most previous studies have hypothesized that things such as duration of loss of consciousness, duration of post-traumatic amnesia and how well patients could perform tasks of thinking, memory, attention, balance and coordination would be the predictors of later disability,” Brody said.
“We looked at these factors. And they were not strongly correlated with how well patients did long term.”