PTSD and Combat-Related Injuries: Functional Neuroanatomy

Abstract

Figure 1. Two recent survey studies of military personnel following deployment indicate that combat-related traumatic brain injury (TBI) is associated with increased incidence of PTSD. 1,2Figure 2. A recent study in identical twins discordant for PTSD reported PTSD-related reductions in gray matter density in the hippocampus (not shown) and several areas of the cortex (pink).3 Both pregenual anterior cingulate cortex (left) and insula (middle) contribute to limbic-related functions.Cover and Figure 3. The influence of TBI location on the development of PTSD is a relatively unexplored area. Interestingly, the few studies that are available agree that TBI involving areas within prefrontal cortex are associated with decreased probability of developing PTSD for both children and adults. A recent study of Vietnam veterans with combat-related penetrating head injuries reported that injury to ventromedial prefrontal and anterior temporal cortices was associated with a lower probability of developing PTSD (left panel). 4 The color-code at the bottom indicates the likelihood of developing PTSD if there is injury to the areas, with larger negative numbers (blue) associated with lower occurrence of PTSD. Note that PTSD was unlikely to develop in veterans with injury to the central white matter of the prefrontal cortex. The studies in children followed a cohort after severe closed head injury. 5,6 One study reported an inverse relationship between lesion burden in the medial frontal gyrus (right, blue) and meeting diagnostic criteria for PTSD. 5 The other reported an inverse relationship between lesion burden in the orbitofrontal cortex (right, purple) and probability of developing PTSD.

Comparison of subjective cognitive complaints with neuropsychological tests in individuals with mild vs more severe traumatic brain injuries

“…Previous research indicates that participants experiencing PTSD symptoms often report more cognitive dysfunction, which was found here as well [33]; however, this was not substantiated on neuropsychological testing. Recent research indicates that individuals with PTSD tend to have increased amygdala activation and decreased medial prefrontal cortical responding to threat [34]. Thus, PTSD may cause the individual to experience cognitive difficulties or compound already existing difficulties.…”

Association between combat stress and post-concussive symptom reporting in OEF/OIF service members with mild traumatic brain injuries

“…In their recent review of the functional neuroanatomy of PTSD and combat-related injuries, Taber and Hurley [22] discussed the possibility that mTBI may potentiate the onset of PTSD. They cite the studies of Hoge et al [2] and Schneiderman [4] which both showed that the incidence of PTSD increases nearly 5-fold in individuals who sustained a mild TBI with loss of consciousness when compared with deployed service members who did not sustain TBIs.…”

The Usefulness of Group Analysis in the Conceptualization and Treatment of ‘Personality Disorders’ and ‘Complex/Post-Traumatic Stress Disorder’

“…Whilst associations do not tell us anything about aetiology and/or causality, traumatization has been linked to dysregulation of the endogenous opioid system, changes in neural activity of neurotransmitters, and structural brain changes (smaller hippocampal, amygdala volumes and anterior cingulate cortex: Karl et al, 2006; disturbances in the prefrontal cortex: Hains and Arnsten, 2008;Taber and Hurley, 2009; decreased activity of Broca's area: Hull, 2002). Furthermore, traumatization has been associated with cardiovascular and gastrointestinal problems, pain and neuroendocrine sensitivity, as well as problems with functioning of the immune system (see Stam, 2007 for review).…”