title: Altered oscillatory brain dynamics after repeated traumatic stress.
abstract: BACKGROUND
  Repeated traumatic experiences, e.g. torture and war, lead to functional and structural cerebral changes, which should be detectable in cortical dynamics. Abnormal slow waves produced within circumscribed brain regions during a resting state have been associated with lesioned neural circuitry in neurological disorders and more recently also in mental illness.
  
  
  METHODS
  Using magnetoencephalographic (MEG-based) source imaging, we mapped abnormal distributions of generators of slow waves in 97 survivors of torture and war with posttraumatic stress disorder (PTSD) in comparison to 97 controls.
  
  
  RESULTS
  PTSD patients showed elevated production of focally generated slow waves (1-4 Hz), particularly in left temporal brain regions, with peak activities in the region of the insula. Furthermore, differential slow wave activity in right frontal areas was found in PTSD patients compared to controls.
  
  
  CONCLUSIONS
  The insula, as a site of multimodal convergence, could play a key role in understanding the pathophysiology of PTSD, possibly accounting for what has been called posttraumatic alexithymia, i.e., reduced ability to identify, express and regulate emotional responses to reminders of traumatic events. Differences in activity in right frontal areas may indicate a dysfunctional PFC, which may lead to diminished extinction of conditioned fear and reduced inhibition of the amygdala.
authors.affiliation: Department of Psychology, Clinical & Neuropsychology, University of Konstanz, 78457 Konstanz, Germany. Iris.Kolassa@uni-konstanz.de
authors.forename: Iris-Tatjana
authors.initials: IT
authors.lastname: Kolassa
authors.forename: Christian
authors.initials: C
authors.lastname: Wienbruch
authors.forename: Frank
authors.initials: F
authors.lastname: Neuner
authors.forename: Maggie
authors.initials: M
authors.lastname: Schauer
authors.forename: Martina
authors.initials: M
authors.lastname: Ruf
authors.forename: Michael
authors.initials: M
authors.lastname: Odenwald
authors.forename: Thomas
authors.initials: T
authors.lastname: Elbert
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D013313:Stress Disorders, Post-Traumatic / Q000503:physiopathology*; D014104:Torture / Q000523:psychology; D014857:Warfare