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Date of Award

Spring 2011

Author's School

College of Arts & Sciences

Author's Department/Program

Biology

Abstract

Traumatic Brain Injury (TBI) is one of the most common, and serious injuries suffered by United States servicemen in the wars in Iraq and Afghanistan. Compared to roughly 2% of the civilian population, nearly 20% of military personnel returning from current military operations in the Middle East have been diagnosed with TBI. Additionally, an increasing number of military personnel returning from deployment have been diagnosed with Post-Traumatic Stress Disorder (PTSD). This is an anxiety disorder typically characterized by experiencing flashbacks of a traumatic event, emotional numbing, as well as both physical and emotional hyperarousal. Current research shows that following brain trauma, such as TBI, qualitative MRI findings may be scarce, or provide little correlation to clinical symptoms. We hypothesized that quantitative, volumetric measurement of the hippocampus following TBI will correlate to onset of PTSD similar to what has been shown in civilian TBI. To test this hypothesis we analyzed MRI scans and psychological data of active duty military personnel who had sustained traumatic brain injury during blast exposure in Iraq or Afghanistan. We measured hippocampal volume using a multi-slice region-of-interest approach on a T1-weighted image. This imaging modality is commonly used in clinical practice for evaluation of brain anatomy. To have a quantifiable measure of PTSD, we analyzed each soldier’s results to the Clinician Administered PTSD scale for DSM-IV (CAPS), a structured interview commonly used to determine a clinically definitive diagnosis. Contrary to our hypothesis and previous literature, we found that hippocampal volume was not correlated to PTSD in this particular population. Interestingly, the total CAPS scores were significantly higher in the TBI group compared to age matched controls suggesting an interaction between TBI and PTSD severity. Specifically, the TBI subjects were significantly more likely to endorse persistently re-experiencing the traumatic event, and avoiding certain stimuli associated with the event.

Language

English (en)

Advisor/Committee Chair

David Brody

Second Advisor

Christine Mac Donald