A preliminary study of alterations in default network connectivity in post-traumatic stress disorder patients following recent trauma.

This study used resting-state functional magnetic resonance imaging (fMRI) to investigate whether functional connectivity is altered in people developing post-traumatic stress disorder (PTSD) following recent trauma. Sixty-two participants who had experienced recent acute traumatic events underwent a 7.3 min resting fMRI scan within 2 days post accident. Of these, 22 participants were diagnosed with PTSD within 1 to 6 months. Nineteen age- and sex-matched subjects without PTSD were selected as the trauma-exposed control group. Posterior cingulate cortex connectivity was determined from 17 PTSD patients and 15 control subjects by investigating synchronic low-frequency fMRI signal fluctuations using a temporal correlation method. To assess the relationship between PTSD symptom severity and PCC connectivity, the contrast image representing areas correlated with the PCC was correlated with the 17 PTSD subjects' Clinician Administered PTSD Scale (CAPS) scores at diagnosis. Compared with the control group, PTSD patients exhibited decreased functional connectivity in the right lingual and right middle temporal gyri, and left lingual/posterior cingulate cortex. The left inferior temporal gyrus, right middle temporal gyrus, left middle temporal gyrus/insula, left medial frontal lobe/anterior cingulate cortex, and right medial frontal gyrus also showed increased connectivity within two days post accident. A negative correlation was found between PCC connectivity and CAPS scores in the left medial prefrontal cortex (mPFC). These results suggest that patients who develop PTSD exhibit different resting-state patterns of neuronal activity following recent trauma. Abnormal FC of mPFC may be a major risk factor predisposing patients to the development of PTSD.