title: Reduced P3b brain response during sustained visual attention is associated with remote blast mTBI and current PTSD in U.S. military veterans.
abstract: Approximately 275,000 American service members deployed to Iraq or Afghanistan have sustained a mild traumatic brain injury (mTBI), with 75% of these incidents involving an explosive blast. Combat-related mTBI is frequently associated with comorbid mental health disorders, especially posttraumatic stress disorder (PTSD). Attention problems, including sustained attention, are common cognitive complaints of veterans with TBI and PTSD. The present study sought to examine neural correlates of sustained attention in veterans with blast mTBI and/or current PTSD. In 124 veterans of Operations Enduring and Iraqi Freedom (OEF/OIF), we examined event-related potentials (ERPs) elicited by targets and non-targets during performance of a degraded-stimulus continuous performance task (DS-CPT). Four groups, consisting of veterans with blast-related mTBI only, current PTSD only, both blast mTBI and PTSD, and a control group, were studied. Compared to all other groups, blast mTBI only participants were more likely to respond regardless of stimulus type during the DS-CPT. During target detection, the three mTBI/PTSD groups showed reduced amplitude of the P3b (i.e., P300) ERP at Pz compared to the control group. P3b of the three affected groups did not differ from each other. These results suggest that parietal P3b amplitude reduction during target detection in the DS-CPT task may be an index of brain pathology after combat trauma, yet the diminished brain response fails to differentiate independent effects of blast-related mTBI or severity of PTSD symptomatology.
authors.affiliation: Defense and Veterans Brain Injury Center, 1 Veterans Dr, Minneapolis, MN 55417, USA; Minneapolis Veterans Affairs Health Care System, 1 Veterans Dr, Minneapolis, MN 55417, USA. Electronic address: casey.gilmore2@va.gov.
authors.forename: Casey S
authors.initials: CS
authors.lastname: Gilmore
authors.affiliation: Minneapolis Veterans Affairs Health Care System, 1 Veterans Dr, Minneapolis, MN 55417, USA; Department of Psychology, University of Minnesota - Twin Cities, 75 E River Rd., Minneapolis, MN 55455, USA.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Marquardt
authors.affiliation: Minneapolis Veterans Affairs Health Care System, 1 Veterans Dr, Minneapolis, MN 55417, USA; Department of Psychology, University of Minnesota - Twin Cities, 75 E River Rd., Minneapolis, MN 55455, USA.
authors.forename: Seung Suk
authors.initials: SS
authors.lastname: Kang
authors.affiliation: Minneapolis Veterans Affairs Health Care System, 1 Veterans Dr, Minneapolis, MN 55417, USA; Department of Psychiatry, University of Minnesota - Twin Cities, 2450 Riverside Ave., Minneapolis, MN 55454, USA.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Sponheim
mesh_terms: D000328:Adult; D055826:Afghan Campaign 2001-; D001288:Attention / Q000502:physiology*; D001753:Blast Injuries / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D001921:Brain / Q000503:physiopathology*; D001924:Brain Concussion / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D054542:Iraq War, 2003-2011; D008297:Male; D009483:Neuropsychological Tests; D013313:Stress Disorders, Post-Traumatic / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D014481:United States; D014728:Veterans / Q000523:psychology; D014796:Visual Perception / Q000502:physiology*; D000067398:War-Related Injuries / Q000150:complications / Q000503:physiopathology / Q000523:psychology
keywords: Attention; Blast; Degraded stimulus-continuous performance task; Mild TBI; P3b; PTSD