Trends in Post-Concussive Symptom Reporting Following Mild Traumatic Brain Injury in Operation Iraqi Freedom

Background: Post-concussive syndrome (PCS), which includes physical, neurological and cognitive complaints, frequently occurs following mild traumatic brain injury (TBI). Research in civilian populations has demonstrated PCS symptom recovery over the course of one-year post-injury, with a majority of symptoms resolving within the first 90 days. The recent military conflicts in Iraq and Afghanistan have resulted in an increased prevalence of TBI, in large part due to a preponderance of blast-related weaponry. Little is known regarding the course of PCS symptoms following combat-related TBI, and whether it differs from other concussion mechanisms seen in civilian populations (e.g., sports-related). Complicating matters is the overlap of symptoms between TBI and post-traumatic stress disorder (PTSD). Methods: The Expeditionary Medical Encounter Database (EMED) allows for the unique assessment of symptoms following mild TBI. The EMED contains clinical records completed in-theatre, which includes exact dates of injury. This addresses limitations of recent research of combat-related TBI, which relies on self-reported information with no knowledge of when the actual event occurred, thus making it impossible to document trends or changes in post-concussive symptoms over time. A non-head injured control group was utilized for comparison purposes. The EMED data was linked with post-deployment health assessment (PDHA) data. The PDHA is given to personnel at the conclusion of their deployment. Because a TBI event can occur at any time during a deployment, personnel can answer a PDHA anywhere from days, weeks to many months after injury. For this analysis, personnel were categorized into those responding to a PDH