FMRI Study Of Mood-regulated Network Abnormalities In Patients With Panic Disorder

In the Diagnostic and Statistical Manual of Mental Disorder, Fifth-Edition, panic disorder is one of the common subtypes of anxiety disorder, which also including social anxiety disorder, generalized anxiety disorder, agoraphobia, separation anxiety disorder, selective mutism and so on. The common patterns in anxiety disorder patients are irrational level of fear and avoiding the inducing factors of anxiety.Anxiety is a kind of subjectively emotional feeling, which appears when individual’s sensitive or unhappy response to negative stimulus. On one hand, anxiety can be regarded as normal reaction to some certain negative stimulus in the environment and inner status of body. This will disappear in a short time in normal. On the other,anxiety also can be named after abnormal action to normal circumstances or in some appropriate conditions. This type of anxiety may last a long time and make huge damages on patients’ health, which is defined as anxiety disorder.Panic Disorder (PD) is a common type of anxiety disorder, typically characterized by recurrent unexpected panic attacks in the normal occasions. Panic attacks are unexpected periods of intense fear that may include palpitations, shaking, sweating,shortness of breath, numbness, or a feeling that something really bad is going to happen.The maximum degree of symptoms occurs within minutes and will not last long. There may be ongoing worries about the coming next attack and avoidance of places where attacks have occurred. Many of them will not go out alone or have no courage to the busy places. However, because of the lack of biological biomarker and overdependence of clinical symphony, the pathophysiology of PD is poorly understood. These years,task-related and fMRI (functional Magnetic Resonance Imaging) have been widely used to in these researches. In this study, we investigated the disease mechanism of PD by contrasting two groups in resting-state fMRI and task-related fMRI.Resting-state fMRI and task-related were performed on 15subjects with PD and 15 matched healthy subjects. Resting-state fMRI data were analyzed using the amplitude of low frequency fluctuation(ALFF) approach and functional connectivity. The task-related fMRI data was analyzed by contrasting the differences in the levels of activation in the two groups in some specific condition. We come to the conclusions:(1) In task-related conditions, as compared with the HCs, brain regions with increased activation by processing positive pictures in PD were left precuneus gyrus and left thalamus; brain regions with increased activation by processing negative pictures in PD were left fusiform gyrus, left hippocampus, left superior occipital gyrus,lingual lobe and calcarine gyrus.In resting-state, PD patients demonstrated decreased ALFF in left precuneus gyrus compared with healthy subjects, at the same time, increased ALFF was found in right fusiform gyrus, right hippocampus lobe, vermis, superior cerebellar lobe. Region of interest(ROI)-based functional connectivity analysis were employed on the basis of seed point of right fusiform gyrus,showing increased FC with left inferior temporal gyrus, the right lingual gyrus, the calcarine gyrus and decreased FC with left middle temporal lobe,right middle frontal gyrus,right middle cingulum,right supplemental motor area.(2)Our results suggest the abnormal activity in default mode network in PD; the activity of the region of precuneus gyrus and hippocampus play a key role in the abnormal activity of default mode network; the fusiform gyrus might be the crucial region to the abnormal activity in regulating the mood in PD.