Increased white matter integrity of posterior cingulate gyrus in the evolution of post-traumatic stress disorder

Objective: Functional imaging studies of post-traumatic stress disorder (PTSD) have shown an increased activation of posterior cingulate gyrus (PCG) of the brain. The aim of this study was to explore white matter integrity of PCG in PTSD subjects. Methods: White matter integrity, as determined from fractional anisotropy (FA) value using diffusion tensor imaging, was assessed for PCG in subjects with and without PTSD from a severe mine accident. All subjects were also measured by the PTSD Checklist Civilian Version (PCL-C), the State-Trait Anxiety Inventory (STAI), the logical memory subtest and the visual reproduction subtest of the Wechsler Memory Scale-Revised in China. Sixteen PTSD subjects (8 subjects in each group) in the longitudinal study and 13 PTSD subjects as well as 14 non-PTSD controls in the cross-sectional case-control study were respectively recruited. Results: In the longitudinal study, subjects with PTSD showed increased FA values in left PCG during the follow-up scan. In the cross-sectional study, FA values in bilateral PCG in PTSD subjects were higher than controls. Within the PTSD group (n = 13), FA values in the left PCG correlated positively with logical memory and negatively with PCL-C intrusion and STAI-trait (STAI-t) subscores. FA values in right PCG correlated negatively with STAI-t and STAI-state subscores. Conclusion: These findings suggest that alterations of white matter integrity in PCG link to mnemonic and affective processing in PTSD over the long-term follow-up period.