Relationship between mechanism of injury and neurocognitive functioning in OEF/OIF service members with mild traumatic brain injuries.

Military personnel deployed to combat theaters in Iraq and Afghanistan are at risk of sustaining mild traumatic brain injuries (mTBI) from causes such as improvised explosive devices, motor vehicle accidents, and falls. Despite the high incidence of mTBI in deployed personnel, questions remain about the effects of blast-related vs. non-blast-related mTBI on acute and long-term sequelae. This investigation is a retrospective review of service members who presented for evaluation of suspected mTBI and underwent neurocognitive screening evaluation, mTBI diagnosis was made by semistructured clinical interview. Only individuals in whom mechanism of injury could be determined (blast vs. non-blast) were included. Sixty individuals were included in the final sample: 32 with blast mTBI and 28 with non-blast mTBI. There were no differences between the blast-related and non-blast-related mTBI groups on age, time since injury, combat stress symptoms, or headache. Analysis of variance showed no significant between-group differences on any of the neurocognitive performance domains. Although speculation remains that the effects of primary blast exposure are unique, the results of this study are consistent with prior research suggesting that blast-related mTBI does not differ from other mechanisms of injury with respect to cognitive sequelae in the postacute phase.