Exploring the Relationship Between Mild Traumatic Brain Injury Exposure and the Presence and Severity of Postconcussive Symptoms Among Veterans Deployed to Iraq and Afghanistan

Abstract Objective The aim of this study was to describe the association between mild traumatic brain injury (mTBI) and persisting postconcussive symptoms according to symptom category, number, and severity. Design The study design was observational. Participants The study sample comprised veterans (≥18 years of age) deployed in Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF) conflicts who had not received any treatment for mTBI in the 30 days preceding study enrollment. Methods Veterans were interviewed and completed testing in a single day. The Standard TBI Diagnostic Interview and the Clinician-Administered PTSD Scale were used. Testing included the Neurobehavioral Symptom Inventory and a full neuropsychological battery. Gold standard classification methods were utilized to determine presence/absence of mTBI. For each of the 5 symptom outcomes, an adjusted multiple linear regression model (negative binomial count models) accounting for effects of socio-demographic variables and behavioral health conditions was used. Main Outcome Measures Self-report of neurobehavioral symptoms categorized as affective, cognitive, somatic, and vestibular symptoms, in addition to the instruments specified above. Results OEF/OIF veterans with mTBI, relative to veterans with no mTBI, were observed to have 30% more symptoms overall ( P P P = .008), 15% more affective symptoms ( P  = .017), and 59% more vestibular symptoms ( P P P P P P Conclusions OEF/OIF veterans with mTBI, relative to veterans with no mTBI, have significantly more and significantly more severe persisting symptoms, with vestibular symptoms reported with the greatest frequency. After accounting for behavioral health conditions and socio-demographic factors, OEF/OIF veterans with mTBI compared to veterans without mTBI had significantly more cognitive, affective, vestibular, and somatic symptoms persisting 4.8 years after the mTBI event(s).