Neuropsychological Outcome from Blast versus Non-blast: Mild Traumatic Brain Injury in U.S. Military Service Members

Abstract

The purpose of this study was to compare the neuropsychological outcome from blast-related versus non-blast related mild traumatic brain injury (MTBI). Participants were 56 U.S. military service members who sustained an MTBI, divided into two groups based on mechanism of injury: (a) non-blast related (Non-blast; n 5 21), and (b) blast plus secondary blunt trauma (Blast Plus; n 5 35). All participants had sustained their injury in theatre whilst deployed during Operation Iraqi Freedom or Operation Enduring Freedom. Patients had been seen for neuropsychological evaluation at Walter Reed Army Medical Center on average 4.4 months (SD 5 4.1) post-injury. Measures included 14 clinical scales from the Personality Assessment Inventory (PAI) and 12 common neurocognitive measures. For the PAI, there were no significant differences between groups on all scales (p. .05). However, medium effect sizes were found for the Depression (d 5 .49) and Stress (d 5 .47) scales (i.e., Blast Plus. Non-blast). On the neurocognitive measures, after controlling for the influence of psychological distress (i.e., Depression, Stress), there were no differences between the Non-blast and Blast Plus groups on all measures. These findings provide little evidence to suggest that blast exposure plus secondary blunt trauma results in worse cognitive or psychological recovery than blunt trauma alone.

Completion of Multidisciplinary Treatment for Persistent Postconcussive Symptoms Is Associated With Reduced Symptom Burden

“…No previous studies specifically investigated the association between TBI blast mechanism and persistent symptom resolution; however, our finding is in contrast with other studies that explored the association between initial persistent symptom burden and blast mechanism and have found no significant difference. [58][59][60][61] Thus, future studies are warranted to establish the true association between blast mechanism and persistent symptom resolution.…”

Functional MRI in the Investigation of Blast-Related Traumatic Brain Injury

“…Finally, some authors have identified quaternary bTBI effects due to other damaging elements associated with the nature of the explosive device used, such as radiation, heat, or the release of chemicals (DeWitt and Prough, 2009). In selecting “blast-injured” TBI subjects for investigations, it is typical to include those with secondary and tertiary effects of blast (sometimes referred to as “blast-plus,” i.e., Moore and Jaffee, 2010; Lange et al, 2012). This is largely due to the rarity of documented isolated primary blast in this population.…”

“…Although differences in injury characteristics likely exist, there are also likely important areas of overlap between blast and non-blast injury mechanisms, injury sequelae, and associated research findings. Certainly from a neurocognitive standpoint, no differences have been found in neuropsychological evaluations between groups of service members sustaining TBI through a blast-related mechanism versus another mechanism (Belanger et al, 2009; Lange et al, 2012). …”

Preliminary findings of cortical thickness abnormalities in blast injured service members and their relationship to clinical findings

“…Currently, it is widely accepted that blast exposure poses a risk to the central nervous system (CNS) of Service Members (SM), though there remains much to be learned about the severity and functional impact. For this reason, blast injury remains a primary focus of many research endeavors across the spectrum of clinical, mechanical, and neuropathology research (Brenner et al 2012; Goeller et al 2012; Lange et al 2012; Panzer et al 2012). …”