Alterations in low-level perceptual networks related to clinical severity in PTSD after an earthquake: a resting-state fMRI study.
BACKGROUND
Several task-based functional MRI (fMRI) studies have highlighted abnormal activation in specific regions involving the low-level perceptual (auditory, visual, and somato-motor) network in posttraumatic stress disorder (PTSD) patients. However, little is known about whether the functional connectivity of the low-level perceptual and higher-order cognitive (attention, central-execution, and default-mode) networks change in medication-naïve PTSD patients during the resting state.


METHODS
We investigated the resting state networks (RSNs) using independent component analysis (ICA) in 18 chronic Wenchuan earthquake-related PTSD patients versus 20 healthy survivors (HSs).


RESULTS
Compared to the HSs, PTSD patients displayed both increased and decreased functional connectivity within the salience network (SN), central executive network (CEN), default mode network (DMN), somato-motor network (SMN), auditory network (AN), and visual network (VN). Furthermore, strengthened connectivity involving the inferior temporal gyrus (ITG) and supplementary motor area (SMA) was negatively correlated with clinical severity in PTSD patients.


CONCLUSIONS
Given the absence of a healthy control group that never experienced the earthquake, our results cannot be used to compare alterations between the PTSD patients, physically healthy trauma survivors, and healthy controls. In addition, the breathing and heart rates were not monitored in our small sample size of subjects. In future studies, specific task paradigms should be used to reveal perceptual impairments.


CONCLUSIONS
These findings suggest that PTSD patients have widespread deficits in both the low-level perceptual and higher-order cognitive networks. Decreased connectivity within the low-level perceptual networks was related to clinical symptoms, which may be associated with traumatic reminders causing attentional bias to negative emotion in response to threatening stimuli and resulting in emotional dysregulation.
Mental Health Center, Department of Psychiatry, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
Jing
J
Shang
Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China; Radiology Department of the Second Affiliated Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
Su
S
Lui
Mental Health Center, Department of Psychiatry, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
Yajing
Y
Meng
Mental Health Center, Department of Psychiatry, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
Hongru
H
Zhu
Mental Health Center, Department of Psychiatry, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
Changjian
C
Qiu
Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
Qiyong
Q
Gong
Center for Cognition and Brain Disorders (CCBD), Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China.
Wei
W
Liao
Mental Health Center, Department of Psychiatry, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
Wei
W
Zhang
D000328:Adult; D001288:Attention / Q000502:physiology; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D002681:China; D055866:Earthquakes; D005260:Female; D059907:Functional Neuroimaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D010465:Perception / Q000502:physiology*; D012720:Severity of Illness Index; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology