Combat exposure, PTSD symptoms, and cognition following blast-related traumatic brain injury in OEF/OIF/OND service members and veterans

Abstract

Traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) are frequently documented among the Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) veterans. This study will investigate both combat exposure and PTSD as factors that may influence objective cognitive outcomes following blast-related mild TBI (mTBI). Participants included 54 OEF/OIF/OND veterans who had been exposed to blast and reported symptoms consistent with mTBI and 43 combat-deployed control participants who had no history of blast exposure or TBI. Raw scores from the Controlled Oral Word Association Test, Trail Making Test, Color-Word Interference Test, and Verbal Selective Reminding Test were used to measure cognitive functioning. All participants demonstrated adequate effort on the Word Memory Test. Demographics, injury characteristics, overall intellectual functioning, and total scores from the PTSD Checklist-Civilian Version (PCL-C) and Combat Exposure Scale (CES) were used as the predictors for each cognitive measure. History of mTBI was significantly associated with higher PCL-C and CES scores. Multivariable linear regression, however, showed no significant differences in cognitive performance between groups. The absence of effect of mTBI, PTSD, and combat exposure on cognitive functioning noted in this study may be partially explained by the inclusion of only those participants who passed performance validity testing.