| BackgroundGeneralised anxiety disorder(GAD)is the most common type of anxiety disorder and is characterised by constant worry or anxiety about everyday life activities and events.At present,the main treatment methods of GAD are drug therapy and psychological intervention.There are many adverse reactions in drug therapy,and psychological therapy is mainly suitable for mild patients.Repetitive transcranial magnetic stimulation(r TMS),as a new neuropsychiatric treatment technique,has attracted much attention because of its high safety and few adverse reactions.However,there is only limited literature on r TMS in the treatment of GAD,and the exact mechanism of remission remains unclear.Resting-state functional magnetic resonance imaging(rs-f MRI)mainly reflects the spontaneous blood oxygen level dependent(BOLD)signal activity of the brain,which is close to the physiological state of neural activity and can provide comprehensive and objective information on brain neurological function,and has become a hot topic in recent years.ObjectiveThe purpose of this study was to analyze the differences in local functional brain activity between the GAD group and healthy control(HC)group by collecting rs-f MRI,combining amplitude of low frequency fluctuation(ALFF)and regional homogeneity(Re Ho),and further analyze the correlation between ALFF and Re Ho values in brain regions with differences and clinical scales,so as to explore the neural mechanism of GAD.In addition,rs-f MRI-based analysis of the changes in ALFF and Re Ho in GAD patients before and after r TMS treatment and their correlation with the degree of clinical symptom improvement to reveal the underlying neural mechanisms of r TMS for GAD.Materials and MethodsIn this study,a total of 16 patients with GAD and 22 healthy controls were collected.All subjects underwent 3D-T1 and rs-f MRI scans on a Siemens 3.0T magnetic resonance machine and were evaluated with the hamilton anxiety scale(HAMA)and hamilton depression scale(HAMD).Among them,12 patients received consecutive 21 days of r TMS treatment,and then underwent 3D-T1,rs-f MRI scans and scale evaluation again after treatment.The scanned images were processed by RESTplus v1.24 software on Matlab2016 b platform,and then analyzed by ALFF and Re Ho.The two independent sample t test was used to compare the differences in brain function indicators between GAD group and HC group.The paired t-test was used to compare the differences in brain function indicators and scale scores of GAD patients before and after treatment.The pearson correlation analysis was used to evaluate the correlation between the ALFF or Re Ho values of brain areas with significant differences and HAMA scores in the GAD group,and the correlation between the difference of ALFF or Re Ho values of brain areas with differences and the improvement value of HAMA scores in GAD patients before and after treatment.P<0.05 was considered statistically significant.Result1.There were no significant differences in gender,age,disease course and years of education between GAD group and HC group(all P>0.05).2.Compared with the HC group,the ALFF values of the right dorsolateral superior frontal gyrus,right medial superior frontal gyrus,bilateral orbital superior frontal gyrus,bilateral superior temporal gyrus and right amygdala increased in the GAD group,while the ALFF values of the right postcentral gyrus and right lingual gyrus decreased(all P<0.05).Compared with the HC group,the Re Ho values of the left orbital superior frontal gyrus,left middle temporal gyrus,bilateral posterior cingulate cortex and left insula were increased in the GAD group,while the Re Ho values of the left postcentral gyrus,left middle occipital gyrus and left cuneus were decreased(all P<0.05).3.The ALFF value of the right orbital superior frontal gyrus in the GAD group was moderately positive correlated with HAMA score.(r=0.526,P=0.036).The Re Ho value of the left orbital superior frontal gyrus in the GAD group was moderately positive correlated with HAMA score.(r=0.579,P=0.019).4.Compared with before r TMS treatment,HAMA and HAMD scores of GAD patients were significantly decreased after treatment(all P<0.001).5.The ALFF values of the left postcentral gyrus and right lingual gyrus in GAD patients after treatment were higher than those before treatment,while the ALFF values of the bilateral anterior cingulate cortex,right amygdala and right insula were lower than those before treatment(all P<0.05).The Re Ho values of the bilateral dorsolateral superior frontal gyrus,left superior temporal gyrus,bilateral anterior cingulate cortex and left insula in GAD patients after treatment were lower than those before treatment(all P<0.05).6.Compared with before r TMS treatment,the decrease of ALFF value in the right anterior cingulate cortex after treatment was moderately positively correlated with the improvement of HAMA score(r=0.688,P=0.013).The decrease of Re Ho value in the left superior temporal gyrus after treatment was moderately positively correlated with the improvement of HAMA score(r=0.623,P=0.030).Conclusion1.Patients with GAD have significant changes in rs-f MRI indicators such as ALFF and Re Ho in several functional brain regions,among which abnormal functional activities of the orbital superior frontal gyrus may play an important role in the occurrence of GAD-related symptoms.2.r TMS is an effective means to improve the clinical symptoms of GAD.r TMS treatment can significantly improve rs-f MRI indicators in several brain regions with abnormal function,and it may also involve changes in the function of the whole brain.In addition,functional changes in the right anterior cingulate gyrus and left superior temporal gyrus may be closely related to the improvement of clinical symptoms. |
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