Structural alterations in lateral prefrontal, parietal and posterior midline regions of men with chronic posttraumatic stress disorder

Abstract

Background: So far, the neural network associated with posttraumatic stress disorder (PTSD) has been suggested to mainly involve the amygdala, hippocampus and medial prefrontal cortex. However, increasing evidence indicates that cortical regions extending beyond this network might also be implicated in the pathophysiology of PTSD. We aimed to investigate PTSD-related structural alterations in some of these regions. Methods: We enrolled highly traumatized refugees with and without (traumatized controls) PTSD and nontraumatized controls in the study. To increase the validity of our results, we combined an automatic cortical parcellation technique and voxel-based morphometry. Results: In all, 39 refugees (20 with and 19 without PTSD) and 13 controls participated in the study. Participants were middle-aged men who were free of psychoactive substances and consumed little to no alcohol. Patients with PTSD (and to a lesser extent traumatized controls) showed reduced volumes in the right inferior parietal cortex, the left rostral middle frontal cortex, the bilateral lateral orbitofrontal cortex and the bilateral isthmus of the cingulate. An influence of cumulative traumatic stress on the isthmus of the cingulate and the lateral orbitofrontal cortex indicated that, at least in these regions, structural alterations might be associated with repeated stress experiences. Voxel-based morphometry analyses produced largely consistent results, but because of a poorer signal-tonoise ratio, conventional statistics did not reach significance. Limitations: Although we controlled for several important confounding variables (e.g., sex, alcohol abuse) with our particular sample, this might limit the generalizibility of our data. Moreover, high comorbidity of PTSD and major depression hinders a definite separation of these conditions in our findings. Finally, the results concerning the lateral orbito frontal cortex should be interpreted with caution, as magnetic resonance imaging acquisition in this region is affected by a general signal loss. Conclusion: Our results indicate that lateral prefrontal, parietal and posterior midline structures are implicated in the pathophysiology of PTSD. As these regions are particularly involved in episodic memory, emotional processing and executive control, this might have important implications for the understanding of PTSD symptoms.PTSD-related alterations in a fronto-parietal brain regions J Psychiatry Neurosci 2011;36(3)

Relationship between Neurocognition and Regional Brain Volumes in Traumatized Adolescents with and without Posttraumatic Stress Disorder

“…Interestingly, a reduction in the bilateral rostral ACC was also seen on VBM which Freesurfer failed to pick up. It should also be mentioned that in the Eckart et al [57] study, significant group differences were only seen between the PTSD and non-traumatized control groups. Using these different imaging paradigms produced varying results in our study.…”

“…Previous work over the past 2 years has compared both these imaging paradigms. Eckart et al [57] compared structural alterations in cortical regions between PTSD-positive participants, traumatized controls and non-traumatized controls, using VBM and Freesurfer. Freesurfer showed a reduction in brain volumes in several areas in the PTSD group (prefrontal regions, the right inferior parietal cortex and bilateral isthmus of the cingulate).…”

“…This could lead to problems with white-grey matter distinction where in age-related studies the brains of older participants may have the appearance of a reduction in grey matter voxels rather than white matter voxels and contribute to a misclassification of grey matter [58]. However, given that previous research [57] has found only partial confirmation between VBM and Freesurfer results, we feel it is prudent to report our uncorrected findings since the areas of significance on VBM support previous findings in adults as well as in adolescents with PTSD [27]. …”

Torture and its Consequences, Psychology of

“…Research is now beginning to acknowledge that soldiers, especially if they were taken as prisoners, might be dealing with trauma symptomology that affects the very sense of self with an altered personality. The changes are related to macroscopically altered brain function in torture survivors Ray et al, 2006) and structure (Eckart et al, 2011). Lateral prefrontal, parietal, and posterior midline structures have been implicated in the pathophysiology inflicted by torture (Eckart et al, 2011).…”

“…The changes are related to macroscopically altered brain function in torture survivors Ray et al, 2006) and structure (Eckart et al, 2011). Lateral prefrontal, parietal, and posterior midline structures have been implicated in the pathophysiology inflicted by torture (Eckart et al, 2011). As these regions are involved specifically in episodic memory, emotional processing, and executive control, this might have important implications for the understanding of the traumarelated symptoms.…”