Altered effective connectivity network of the amygdala in posttraumatic stress disorder:a study based on granger causality analysis

Objective To explore the alteration of the effective connectivity between amygdala and other brain regions in posttraumatic stress disorder(PTSD)patients.Methods Fifty-seven patients with PTSD and seventy-seven controls who survived from the Wenchuan earthquake underwent the resting-state functional magnetic imaging scan.Granger causality analysis was used to compare the effective connectivity network of amygdala between PTSD patients and controls.In addition,Pearson correlation was performed between abnormal Granger causality and the Clinician-Administered PTSD Scale(CAPS)score of patients.Results Compared with controls,PTSD patients showed decreased influence from amygdala to medial frontal gyrus,cingulate cortex,superior and inferior frontal gyri,superior and inferior temporal gyri,putmen,and inceased influence from amygdala to hippocampus,parahipocampal gyrus,cuneus,precuneus and thalama.Furthermore, PTSD patients exhibited decreased influence from medial and middle frontal gyri,superior and middle temporal gyri,insular,putamen to amygdala,and increased influence from cuneus,precuneus and parahippocampal gyrus to amygdala.The CAPS score was negatively correlated with effective connectivity from amygdala to superior and inferior temporal gyri, from middle frontal gyrus to amygdala,and positively correlated with effective connectivity from amgdala to precuneus. Conclusion The effective connectivity network of amygdala is widespreadly disrupted in PTSD patients,and is partly correlated with their disease severity.