A Resting State FMRI Study Of The Orbitofrontal Cortex And Its Neural Circuits In Patients With Panic Disorder

Panic Disorder(PD)was characterized by sudden panic attacks(PA)in the absence of obvious terrifying stimuli,with a sense of impending death and loss of control.PD patients were impaired in terms of cognition,emotional processing and memory.The Orbitofrontal Cortex(OFC)was located in the prefrontal cortex and was widely associated with the amygdala and anterior cingulate gyrus.It was an important center for processing visual,spatial and emotional information in the central nervous system.Some studies have been found that structural abnormalities of OFC in PD patients related to their fear and avoidance.Cognitive behavioral therapy has been found to have good effects on PD,which was related to the role of OFC in emotional decision making and cognitive flexibility.This study has been received 23 PD patients according to DSM-5 in Nanjing Brain hospital and 25 matched healthy people.After all the participants were enrolled,data of the General Survey of Subjects,the Hamilton Anxiety Scale(HAMA),the Hamilton Depression Scale(HAMD),the Panic Disorder Severity Scale(PDSS),and the Resting Functional Magnetic Resonance Imaging(fMRI)were collected.Firstly,the fMRI data were analyzed by the Functional Connectivity Density(FCD)method,and the differential brain regions of the PD group and the HC group were compared with two-sample t test.The OFC in the differential brain region was used as ROI to explore abnormal functional connection of the PD group compared with the HC group by the functional connectivity(FC)method.The effect connection of OFC has been determined by Granger Causality Analysis(GCA),and SPSS was used to correlate brain and scale scores.The results were as follows:(1)Changes in FCD of the PD group compared with the HC groupAccording to the two-sample t test results of two groups,the IFCD of frontal_sup_orb_R,frontal_med_orb decreased,the longFCD of frontal_med_orb,frontal_sup_orb,frontal_mid_orb,frontal_inf_orb_R decreased.The OFC was negatively correlated with the HAMA,HAMD and PDSS scores.(2)Changes in FC of the PD group compared with the HC groupExtracting the ROI from IFCD,functional connection between OFC and insula,supramarginal gyrus,precentral gyrus,postcentral gyrus decreased.And extracting the ROI from longFCD,functional connection between OFC and lingual gyrus,insula,supramarginal gyrus,caudate,amygdala,anterior cingulate changed.(3)The effect connection in the PD group compared with the HC groupUsing the ROI in study(2),the Granger causality analysis was performed on the two groups,and GCA were extracted and correlated with clinical scale scores.It was found that there were effect connections in the OFC of PD group,left supramarginal gyrus?frontal_med_orb_R,frontal_mid_orb?right parahippocampal gyrus,frontal_med_orb?fright parahippocampal gyrus.Conclusion as below:(1)The IFCD and longFCD in OFC of the PD group compared with the HC group were decreased,and OFC was correlated with the clinical scale scores,so the OFC was an important brain region in the brain circuit of PD.(2)The brain function connection of OFC and insula,supramarginal gyrus,precentral gyrus,postcentral gyrus of PD were abnormal.The effect connections of OFC were included parahippocampal gyrus,supramarginal gyrus,and GCA was correlated with the clinical scale scores.OFC was associated with clinical symptoms of PD.