title: Reduced prefrontal MEG alpha-band power in mild traumatic brain injury with associated posttraumatic stress disorder symptoms.
abstract: To determine if changes in cortical alpha-band power in patients with mild traumatic brain injury (mTBI) are associated with the severity of their post-traumatic stress disorder (PTSD) symptoms, and if injury severity and level of exposure to psychologically traumatic events are predictors of these electrophysiological changes.
  
  
  
  Resting-state magnetoencephalographic recordings were analyzed in 32 patients with mTBI. Alpha-band power was estimated for each patient in 68 cortical regions and was compared between groups of patients with low versus high PTSD symptoms severity.
  
  
  
  Participants with high PTSD symptom severity showed reduced alpha-band power bilaterally in the superior and middle frontal gyri and frontal poles, and in the left inferior frontal gyrus. Alpha-band power in bilateral middle frontal gyri and frontal poles was negatively correlated with scores reflecting symptoms of emotional numbing. Loss of consciousness (LOC) associated with mTBI and level of exposure to psychologically traumatic events were predictors of decreased prefrontal alpha-band power in some of these regions.
  
  
  
  Altered prefrontal alpha-band activity, shown to be partly explained by mTBI-related LOC, is associated with PTSD symptoms severity.
  
  
  
  Our findings will guide future studies addressing the electrophysiological mechanisms underlying a higher incidence of PTSD in patients with mTBI.
authors.affiliation: National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD, USA.
authors.forename: Mihai
authors.initials: M
authors.lastname: Popescu
authors.affiliation: National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD, USA; Department of NeuroTrauma, Naval Medical Research Center, Silver Spring, MD, USA. Electronic address: john.d.hughes4.mil@mail.mil.
authors.forename: John D
authors.initials: JD
authors.lastname: Hughes
authors.affiliation: National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD, USA.
authors.forename: Elena-Anda
authors.initials: EA
authors.lastname: Popescu
authors.affiliation: National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD, USA.
authors.forename: Gerard
authors.initials: G
authors.lastname: Riedy
authors.affiliation: National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: DeGraba
mesh_terms: D000328:Adult; D000513:Alpha Rhythm / Q000502:physiology; D001924:Brain Concussion / Q000453:epidemiology / Q000503:physiopathology* / Q000523:psychology; D003430:Cross-Sectional Studies; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D008889:Military Personnel / Q000523:psychology; D017397:Prefrontal Cortex / Q000503:physiopathology*; D057566:Self Report; D013313:Stress Disorders, Post-Traumatic / Q000453:epidemiology / Q000503:physiopathology* / Q000523:psychology; D014474:Unconsciousness / Q000453:epidemiology / Q000503:physiopathology / Q000523:psychology
keywords: Alpha-band oscillations; Magnetoencephalography; Post-traumatic stress disorder; Resting-state; Traumatic brain injury