PTSD and Combat-Related Injuries: Functional Neuroanatomy

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.1,2 Figure 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 th