Symptoms in military service members after blast mTBI with and without associated injuries.

Traumatic combat events can lead to neurobehavioral and stress-related symptoms among military troops. Physical injuries received during combat are associated with increased symptom report. The effect of a concurrent mild traumatic brain injury (mTBI) on this relationship is unknown and forms the basis for this report. Subjects included a cohort of 274 male service members who received a blast-related mTBI during deployment in Iraq. They completed symptom ratings on the Posttraumatic Stress Disorder Checklist-Civilian version (PCL-C) and Neurobehavioral Symptom Inventory (NSI). Service members with mTBI, but no other associated physical injuries had higher symptom ratings than those who received mTBI plus associated injuries. Results suggest that in the presence of an invisible injury, such as mTBI, associated bodily injuries may be at least partially protective against the development of stress and neurobehavioral symptoms. It is proposed that an invisible wound, such as mTBI, creates ambiguity regarding the etiology of symptoms and expected course of recovery and leads to increased emotional and somatic symptom report. However, the observable nature of an associated physical injury and the systematic rehabilitation involved in recovery from such an injury provide a focus for attention and measurable progress toward recovery that serve to reduce emotionally-based symptom reports.