The Study On MECT Anti-depressant Mechanism Of Resting-state Functional Magnetic Resonance Imaging

Objective: To observe changes of brain function and structure at resting state in patients with major depression before and after modified electroconvulsive therapy(MECT) with functional magnetic resonance imaging, to explore the antidepressant mechanism of MECT.Methods: 20 major depressive patients,which met with DSM-4-TR diagnosis criteria were recruited, and 24-item Hamilton Depression Rating Scale(HAMD) score were requested no less than 35, and conformed to the electric shock treatment indications(SCI- D diagnostic program). HAMD,HAMA,SSI,MADRS were assessed and magnetic resonance imaging were performed before and after a course of MECT therapy(6 to 12). The magnetic resonance imagingwere compared using ReHo、rs FCD、ALFF、GMV analysis, to observe the differences in brain function in major depressive patients.Results: 1. rsFCD was significantly decreased in the left medial superior frontal gyrus and right frontal medial orbital cortex in depression patients after ECT, compared with patients before ECT(P=0.004, AlphaSim corrected).2. Patients after ECT also exhibited decreased ReHo in the bilateral cunei, calcarine gyri, left lingual gyrus, middle occipital gyrus and right fusiform gyrus and increased ReHo in the right middle occipital gyrus and inferior parietal lobe(P=0.001, AlphaSim corrected).3. Decreased ALFF in the right calcarine gyrus and increased ALFF in the left triangular parts of the inferior frontal gyrus and the right superior frontal gyrus were observed in patients after ECT relative to patients before ECT(P=0.003, AlphaSim corrected).4. Depression patients after ECT also showed increased GMV in the medial superior frontal gyrus, middle frontal gyrus, superior frontal gyrus and right thalamus(P=0.005, AlphaSim corrected).Conclusions: 1. The significantly decrease of rsFCD in the left medial superior frontal gyrus and right frontal medial orbital cortex in depression patients after ECT, which may be the mechanism of ECT to improve depressiveemotion.2. The result of ECT leads to a decrease of function activity of fusiform gyrus(ReHo values decrease),whichmay be one of the mechanism of ECT’s antidepression;3. The rise and fall of the ALLF of the frontal lobe may be an indicator as to evaluate the treatment effect and the severity of depression;4. To major depression patients, the increase of the gray matter volume of frontal lobe after ECT is likely to be a mechanism of its efficacy and possible as an indicator of ECT’s treatment effect.