Posttraumatic stress disorder: Structural characterization with 3-T MR imaging

Purpose: To explore cerebral alterations related to the emergence of posttraumatic stress disorder (PTSD) by using threedimensional T1-weighted imaging and also to explore the relationship of gray and white matter abnormalities and the anatomic changes with clinical severity and duration of time since the trauma. Materials and Methods: Informed consent was provided, and the prospective study was approved by the ethics committee of the West China Hospital. Recruited were 67 patients with PTSD and 78 adult survivors without PTSD 7-15 months after a devastating earthquake in western China. All participants underwent magnetic resonance (MR) imaging with a 3-T imager to obtain anatomic images. Cortical thickness and volumes of 14 subcortical gray matter structures and five subregions of the corpus callosum were analyzed with software. Statistical differences between patients with PTSD and healthy survivors were evaluated with a general linear model. Averaged data from the regions with volumetric or cortical thickness differences between groups were extracted in each individual to examine correlations between morphometric measures and clinical profiles. Results: Patients with PTSD showed greater cortical thickness in the right superior temporal gyrus, inferior parietal lobule, and left precuneus (P <.05; Monte Carlo null-z simulation corrected) and showed reduced volume in the posterior portion of the corpus callosum (F = 6.167; P =.014) compared with healthy survivors of the earthquake. PTSD severity was positively correlated with cortical thickness in the left precuneus (r = 0.332; P =.008). The volumes of posterior corpus callosum were negatively correlated with PTSD ratings in all survivors (r = 20.210; P =.013) and with cortical thickness of the left precuneus in patients with PTSD (r = 20.302; P =.017). Conclusion: Results indicate that patients with PTSD had alterations in both cerebral gray matter and white matter compared with individuals who experienced similar psychologic trauma from the same stressor. Importantly, early in the course of PTSD, gray matter changes were in the form of increased, not decreased, cortical thickness, which may have resulted from neuroinflammatory or other trophic process related to endocrine changes or functional compensation.