Perfusion Deficits and Functional Connectivity Alterations in Memory-Related Regions of Patients with Post-Traumatic Stress Disorder

Abstract

To explore the potential alterations in cerebral blood flow (CBF) and functional connectivity of recent onset post-traumatic stress disorder (PTSD) induced by a single prolonged trauma exposure, we recruited 20 survivors experiencing the same coal mining flood disaster as the PTSD (n = 10) and non-PTSD (n = 10) group, respectively. The pulsed arterial spin labeling (ASL) images were acquired with a 3.0T MRI scanner and the partial volume (PV) effect in the images was corrected for better CBF estimation. Alterations in CBF were analyzed using both uncorrected and PV-corrected CBF maps. By using altered CBF regions as regions-of-interest, seed-based functional connectivity analysis was then performed. While only one CBF deficit in right corpus callosum of PTSD patients was detected using uncorrected CBF, three more regions (bilateral frontal lobes and right superior frontal gyrus) were identified using PV-corrected CBF. Furthermore, the regional CBF of right superior frontal gyrus exhibited significantly negative correlation with the symptom severity (r = −0.759, p = 0.018). The resting-state functional connectivity analysis revealed increased connectivity between left frontal lobe and right parietal lobe. The results indicated the symptom-specific perfusion deficits and an aberrant connectivity in memory-related regions of PTSD patients when using PV-corrected ASL data. It also suggested that PV-corrected CBF exhibits more subtle changes that may be beneficial to perfusion and connectivity analysis.

Decreased Triple Network Connectivity in Patients with Recent Onset Post-Traumatic Stress Disorder after a Single Prolonged Trauma Exposure

“…With the recruited PTSD and non-PTSD groups in this study, each group had 10 male subjects. As expected, the PTSD group had higher CAPS scores than those of non-PTSD group (PTSD: 78.72 ± 17.2, non-PTSD: 31.40 ± 18.57, p < 0.001) and two groups significantly differed in age (PTSD: 40.80 ± 6.83, non-PTSD: 34.30 ± 5.37, p = 0.032) 16 . The study was conducted according to the principles in the Declaration of Helsinki and approved by the Institutional Board of the Fourth Military Medical University.…”

“…The present study was an extension of our previous structural and functional studies using the same subjects, in which we have identified a series of nodes in three key ICNs with volume deficits 3 , cortical thinning 1 , and CBF deficits 16 . Combined with decreased triple network connectivity presented in this study, our multimodality studies indicate that structural and functional deficits may contribute to cognitive dysfunction of the specific PTSD.…”

“…In contrast, ASL sequence can provide the absolute quantification of CBF 36 , which may help interpret the ambiguous results concerning functional connectivity of networks in mental diseases 36 , 37 . Our previous study used effective partial volume (PV) correction method to improve the quality of ASL image, which has been confirmed to be beneficial to perfusion and connectivity analysis 16 .…”

“…In contrast to most PTSD studies focusing on subjects who experienced repeated and short-duration traumas 1 , such as earthquake or abuse experience, few studies have investigated the effect of recent onset PTSD induced by a single prolonged trauma exposure. In our previous studies, which used structural and perfusion MRI data acquired from survivors experiencing a mining flood disaster, a series of structural and functional alterations were identified at nodes of the three ICNs, including volume deficits in left hippocampus and parahippocampal gyrus 3 , cortical thinning in the left precuneus and right parahippocampal gyrus 1 , and cerebral blood flow (CBF) deficits in bilateral frontal lobes and right superior frontal gyrus 16 . The integration of these findings suggests possibly decreased connectivity within these ICNs, due to volume, cortical thickness, and CBF deficits.…”

“…To investigate possible alteration of the triple network connectivity in patients with PTSD induced by a single prolonged trauma exposure, in this study, further analysis was performed between survivors with PTSD and without PTSD, who experienced the same coal mining flood disaster. Based on CBF maps estimated from pulsed arterial spin labeling (ASL) time series 16 , we first extracted independent components (ICs) from CBF time-series to identify three ICNs. Then the reconstructed network connectivity within and between the three networks were compared between two groups.…”