Altered Resting-state Functional Connectivity of Thalamus in Earthquake-induced Posttraumatic Stress Disorder: a Functional Magnetic Resonance Imaging Study

Background: Thalamic dysfunction has been found in patients with posttraumatic stress disorder (PTSD), suggesting that the thalamus may be implicated in the etiology of PTSD. However, no studies have explored the functional connectivity between the thalamus and other brain regions during resting-state. The objective of the present study was to investigate the resting-state functional connectivity of the thalamus in recent onset medication-naive PTSD sufferers who went through an earthquake in the Sichuan province of China.

Methods: Fifty-four participants with PTSD and seventy-two age and gender matched traumatized controls without PTSD recruited from the 2008 Sichuan earthquake were scanned by 3T functional magnetic resonance imaging (fMRI) in resting state. Region of interest (ROI)-based functional connectivity analysis was employed to identify the potential differences in the functional connectivity of the thalamus between the two groups.

Results: In the PTSD group, the thalamus-ROIs showed decreased positive functional connectivity to particular brain regions including right medial frontal gyrus and left anterior cingulate cortex. Importantly, we also found increased positive functional connectivity of thalamus-ROIs with bilateral inferior frontal and left middle frontal gyri, left inferior parietal lobule as well as right precuneus in the PTSD participants when compared to traumatized controls without PTSD.

Conclusion: The results provide evidence that abnormal resting state functional connections linking the thalamus to cortical regions may be involved in the underlying pathology in PTSD.