The Gama-aminobutyric Acid Of Prefrontal Cortex With Magnetic Resonance Spectroscopy Technology And Resting-state Functional MRI Study In Obsessive-compulsive Disorder

Objective: Obsessive-compulsive disorder(OCD)is a mental disorder with repeatedly,and interference thoughts,ideas or imagination(obsession)and repeated behaviors(compulsive behavior).In recent years,Numerous neuroimaging studies have indicated the metabolism and functional dysfunctions in cortico-striato-thalamo – cortical(CSTC)loop in patients with obsessive-compulsive disorder(OCD),especially the prefrontal cortex.This research adopted magnetic resonance spectrum technology(MRS)and resting-state functional MRI study based on amplitude of low frequency Amplitude(ALFF)to study the characteristics of neural metabolism and function in patients with obsessive-compulsive disorder.Also,we analyzed the the relationship between the abnormal metabolism and function with the clinical symptoms.Methods: 82 durg-na?ve or drug-free(eight weeks or more)patients with obsessive-compulsive disorder and 81 well-matched(gender,age,and education)healthy controls were enrolled in study.We adopted magnetic resonance spectrum technique and resting-state f MRI technology based on ALFF.We apllied 3.0 T Siemens MRI scanner to collect datas,based on LCmodel6.3 to analysis gamma aminobutyric acid(GABA)concentrations in OFC and anterior cingulate cortex.Based on ALFF to analyze brain neurons activity.Using two-sample t test to analyze the differences in the concentration of metabolic substances between OCD and health control group.Then based on Pearson correlation to detect the correlation between the abnormal metabolism and the scores of Y BOCS,HAMA and HAMD.We also applied ANOVA to analyze the withingroup difference of OCD according to sex and drug information.To the resting state f MRI data,we applying SPM8 and Rest1.6 software to analyze ALFF of local brain regions in the resting state,ALFF value of two groups apply for two sample t test.Last,we exteact OFC signals to correlate with metabolism.Results:1.Compared with healthy controls,GABA/W(p = 0.031,t =-2.193)of OFC were significantly reduced in OCD.GABA/W of ACC(p = 0.059,t =-1.921)has a trend to decrease.GABA/W of OFC was significantly negativly correlated with Yale-brown compulsive compulsion,behavior and total score(p = 0.037,r = 0.221;p = 0.007,r =-0.283;p = 0.014,r =-0.259).NAA was negativly correlated with Yale-brown compulsive compulsion,behavior and total score,HAMD,HAMA,first age(p=0.00,r=-0.33;p=0.00,r=-0.38;p=0.00.r=-0.36;p=0.01,r=-0.26;p=0.00,r=-0.32;p=0.00,r=-0.35)。2.Compared with healthy controls,the ALFF value significantly increased in these brain regions: bilateral Temporal,left Gyrus rectus,bilateral OFC,left DLPFC.The ALFF value significantly decreased in these brain regions: Occipital lobe,left Cerebelum,Parietal lobe,Angular gyrus and Primary motor cortex.(p<0.05,corrected with Alpha Sim)The ALFF of OFC were no correlation with metabolism.Conclusions: Results showed that GABA/W was abnormal of OFC in OCD,ACC has the tendency to decrease,and GABA/W is associated with clinical symptoms which prompt the role of GABA in the pathogenesis of obsessive-compulsive disorder.While resting state fmri also found that increased ALFF in OFC,maybe the reduction of GABA is corrlated with the excessive activity of the neurons,which provide the evidences for the pathogenesis of obsessive-compulsive disorder.