No Significant Acute and Subacute Differences between Blast and Blunt Concussions across Multiple Neurocognitive Measures and Symptoms in Deployed Soldiers

Seventy-one deployed U.S. Army soldiers who presented for concussion care due to either blast or blunt mechanisms within 72 h of injury were assessed using the Military Acute Concussion Evaluation, the Automated Neuropsychological Assessment Metrics (ANAM), traditional neuropsychological tests, and health status questionnaires. Follow-up ANAM testing was performed 10 d after initial testing (±5 d). Twenty-one soldiers were excluded: two for poor effort and 19 who had combined blast/blunt injuries. Of the remaining 50 male participants, 34 had blast injuries and 16 had blunt injuries. There were no statistically significant differences between blast injury and blunt injury participants in demographic, physical, or psychological health factors, concussive symptoms, or automated and traditional neurocognitive testing scores within 72 h post-injury. In addition, follow-up ANAM scores up to 15 d post-injury were not significantly different (available on 21 blast-injured and 13 blunt-injured subjects). Pre-injury baseline ANAM scores were compared where available, and revealed no statistically significant differences between 22 blast injury and eight blunt injury participants. These findings suggest there are no significant differences between mechanisms of injury during both the acute and subacute periods in neurobehavioral concussion sequelae while deployed in a combat environment. The current study supports the use of sports/mechanical concussion models for early concussion management in the deployed setting and exploration of variability in potential long-term outcomes.