Characterization of mild traumatic brain injury events and indices of psychological health in OEF/OIF veterans

Depression, PTSD, and PCS have been shown to be linked to mild traumatic brain injury (mTBI) events such as blast and concussion, often with onset months after the initial injury. A perspective cohort study was conducted with OEF/OIF recent combat veterans (n=79) to search for neurophysiological predictors of delayed-onset psychological symptoms. A comprehensive chart review, based on medical history and structured patient interviews, categorized the mTBI events by factors suspected or shown by research to be correlated onset of psychological symptoms.  Differences in mTBI event between each study group were compared.  Study participants also underwent additional testing and screenings in the following areas for later correlation with mTBI event history:  psychometric screenings (alcoholism, combat history), indicators of psychophysiology (heart rate variability, skin conductance, brain synchronization, startle response), physiology (biomarkers/neuroendocrine measures, vestibular/olfactory testing, fMRI imaging), and virtual reality exposure (“Virtual Iraq”).  Long-term goals of the study are to find quantifiable predictors of future psychological illnesses, with the aim to identify and treat veterans before the onset of severe symptomatology such as suicide. Multivariate analysis will correlate features of the mTBI event with measures of psychological illness and neurophysiological measures listed above.  Measures of depression were explored as a proof of concept. Poor retention rates hampered extensive, statistically meaningful analysis of the relationship of mTBI events and depression severity, though suggest that the etiology of recent, blast mTBI makes an individual more vulnerable to experience persistent symptoms.  Methods have been suggested for future studies to improve statistical power of the existing data.