Changes in brain anatomy during the course of posttraumatic stress disorder

Abstract

The goal of this study was to determine whether posttraumatic stress disorder (PTSD) was associated with an increase in time-related decline in macrostructural brain volume and whether these changes were associated with accelerated cognitive decline. To quantify brain structure, three-dimensional T1-weighted MRI scans were performed at baseline and again after a minimum of 24months in 25 patients with PTSD (PTSD+) and 22 controls (PTSD-). Longitudinal changes in brain volume were measured using deformation morphometry. For the group as a whole, PTSD+ patients did not show significant ongoing brain atrophy compared to PTSD-. PTSD+ patients were then subgrouped into those with decreasing or increasing symptoms. We found little evidence for brain markers of accelerated atrophy in PTSD+ veterans whose symptoms improved over time, with only a small left parietal region showing greater ongoing tissue loss than PTSD-. PTSD patients whose symptoms increased over time showed accelerated atrophy throughout the brain, particularly brainstem and frontal and temporal lobes. Lastly, for the sample as a whole, greater rates of brain atrophy were associated with greater rates of decline in verbal memory and delayed facial recognition.

Figure 1

The magnitude of the group difference and the statistically significant differences between PTSD- and PTSD+ groups are mapped, overlaid on the spatially normalized average brain. The top panel shows the comparison between PTSD- and PTSD+ Improvers; the bottom show PTSD- vs. PTSD+ Non-Improvers. The green/blue voxels show regions of greater atrophy rate in PTSD+; the pink shaded voxels show regions statistically significant after correction for multiple comparisons.

Figure 2

The magnitude of the regression coefficient estimate of the rate of atrophy regression onto change in cognitive score and the regions where these estimates are significantly different from zero are mapped, overlaid on the spatially normalized average brain. The top panel shows the association between rate of atrophy and change in delayed verbal memory (CVLT delayed score) and the bottom panel shows associations with change in delayed facial recognition. The green/blue voxels show regions where greater atrophy rate was underlying cognitive decline; the pink shaded voxels show regions statistically significant after correction for multiple comparisons.