title: Combat veterans with PTSD after mild TBI exhibit greater ERPs from posterior-medial cortical areas while appraising facial features.
abstract: Posttraumatic stress disorder (PTSD) worsens prognosis following mild traumatic brain injury (mTBI). Combat personnel with histories of mTBI exhibit abnormal activation of distributed brain networks-including emotion processing and default mode networks. How developing PTSD further affects these abnormalities has not been directly examined. We recorded electroencephalography in combat veterans with histories of mTBI, but without active PTSD (mTBI only, n=16) and combat veterans who developed PTSD after mTBI (mTBI+PTSD, n=16)-during the Reading the Mind in the Eyes Test (RMET), a validated test of empathy requiring emotional appraisal of facial features. Task-related event related potentials (ERPs) were identified, decomposed using independent component analysis (ICA) and localized anatomically using dipole modeling. We observed larger emotional face processing ERPs in veterans with mTBI+PTSD, including greater N300 negativity. Furthermore, greater N300 negativity correlated with greater PTSD severity, especially avoidance/numbing and hyperarousal symptom clusters. This correlation was dependent on contributions from the precuneus and posterior cingulate cortex (PCC). Our results support a model where, in combat veterans with histories of mTBI, larger ERPs from over-active posterior-medial cortical areas may be specific to PTSD, and is likely related to negative self-referential activity.
authors.affiliation: VISN-22 Mental Illness, Research, Education and Clinical Center, 3350 La Jolla Village Drive, #116A, San Diego, CA 92161, USA; Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Drive, #116A, San Diego, CA 92161, USA. Electronic address: ishu@ucsd.edu.
authors.forename: I-Wei
authors.initials: IW
authors.lastname: Shu
authors.affiliation: Naval Health Research Center, 140 Sylvester Rd, Department 162, San Diego, CA 92106, USA.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Onton
authors.affiliation: Department of Psychiatry, University of California San Diego, 9500 Gilman Drive #9116A, La Jolla, CA 92037, USA.
authors.forename: Nitin
authors.initials: N
authors.lastname: Prabhakar
authors.affiliation: Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Drive, #116A, San Diego, CA 92161, USA; Department of Psychiatry, University of California San Diego, 9500 Gilman Drive #9116A, La Jolla, CA 92037, USA.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: O'Connell
authors.affiliation: Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Drive, #116A, San Diego, CA 92161, USA; Veterans Affairs San Diego Healthcare System Center of Excellence for Stress and Mental Health, 3350 La Jolla Village Drive, #116A, San Diego, CA 92161, USA.
authors.forename: Alan N
authors.initials: AN
authors.lastname: Simmons
authors.affiliation: VISN-22 Mental Illness, Research, Education and Clinical Center, 3350 La Jolla Village Drive, #116A, San Diego, CA 92161, USA; Veterans Affairs San Diego Healthcare System Center of Excellence for Stress and Mental Health, 3350 La Jolla Village Drive, #116A, San Diego, CA 92161, USA.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Matthews
mesh_terms: D001930:Brain Injuries / Q000150:complications*; D003130:Combat Disorders / Q000175:diagnosis / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D004569:Electroencephalography; D004644:Emotions; D005071:Evoked Potentials / Q000502:physiology*; D005145:Face; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis / Q000503:physiopathology*; D014728:Veterans / Q000523:psychology* / Q000706:statistics & numerical data
keywords: Biomarker; Mild TBI; N300; PTSD; Posterior cingulate cortex; Precuneus