New research shows four distinct patterns of symptoms after mild traumatic brain injury (TBI) in military service members, and validates a new tool for assessing the quality-of-life impact of TBI. The studies appear in the January-February issue of The Journal of Head Trauma Rehabilitation (JHTR), an annual special issue devoted to TBI in the military. The official journal of the Brain Injury Association of America, JHTR is published by Wolters Kluwer.

In print and online, the special issue presents 13 original research studies on TBI in the military, including a special focus on how TBI affects quality of life (QOL). Traumatic brain injury is a major concern in military personnel, both deployed and nondeployed. Estimates suggest that more than 294,000 service members sustained TBI between 2000 and 2013. More than 80 percent of these injuries were mild TBI, also known as concussion.

Four Subtypes of Symptoms after Military TBI

Jason M. Bailie, PhD, of the Defense and Veterans Brain Injury Center (DVBIC) and colleagues analyzed patterns of neurobehavioral and psychiatric symptoms in more than 1,300 veterans who had sustained combat-related mild TBI within the past two years. The goal was to develop a classification, or "taxonomy," of symptoms after mild TBI in military personnel.

The analysis identified four "clusters," or subtypes, of symptoms. The largest group of veterans--about 38 percent--had good recovery, with relatively low rates of behavioral and mental health symptoms.

About 22 percent of veterans had primarily psychiatric symptoms. This included mood symptoms associated with traumatic stress disorder (PTSD), such as hyperarousal and dissociation or depression. But they were less likely to have cognitive (thinking) difficulties or headaches.

Another 22 percent had primarily cognitive symptoms and headaches, with few mood problems. The remaining 19 percent of veterans fell into a "mixed" subtype, with a combination of mood problems, cognitive complaints, and headaches.

Some other characteristics also differed between groups, including the timing of TBI and the severity of other injuries. While emphasizing that their classification is preliminary, Dr. Bailie and coauthors conclude, "The clinical differences among these subtypes indicate a need for unique treatment resources and programs."

New Questionnaire for Assessing QOL after Military TBI

Rael T. Lange, PhD, of the DVBIC and colleagues report an evaluation of the "TBI-QOL"--a new questionnaire for assessing health-related quality of life after TBI. The TBI-QOL evaluates 20 subscales in the areas of physical and emotional health, cognition, and social participation.

The researchers compared TBI-QOL scores for about 100 veterans with mild TBI versus smaller groups of injured or uninjured veterans without TBI. The results showed good reliability and validity, providing evidence that the responses were consistent and accurate. The TBI-QOL also performed well in distinguishing between veterans with and without TBI.

Veterans with TBI scored worse than the other groups on ten out of 14 subscales. The differences were largest in areas reflecting cognitive function, grief and loss, pain interfering with daily activities, and headache. Somewhat surprisingly, the differences were not as great for symptoms of anxiety and depression.