Comparative Study On The Regional Homogeneity Of Resting State Before And After Treatment In Patients With Blepharospasm

Background:Blepharospasm(BSP)is a dystonic disorder caused mainly by involuntary spasm of the orbicularis oculi muscle.Although previous multi-functional MRI cross-sectional studies have found functional abnormalities in several brain regions in BSP patients by various methods,the pathogenesis of BSP has not been clear yet.This study will use the resting state functional magnetic resonance imaging(RS-f MRI)to study the patients with BSP before and after treatment,and analyze the changes in brain function of patients through the regional homogeneity(ReHo)method.To further clarify the mechanism of central nervous system dysfunction of BSP,and to explore the physiological and pathological mechanisms of BSP.Methods: Rs-f MRI scans of the brain were performed in 19 BSP patients and 23 healthy adults.BSP patients were treated with botulinum toxin type A for one month and rs-f MRI scans were performed again.The brain function activity of BSP patients pretherapy and post-treatment was compared with that of healthy control group by ReHo analysis,and then the brain function of BSP patients pretherapy and post-treatment was compared.Pearson correlation analysis was performed between the ReHo value of different part of brain and the severity of symptoms(JRS score)in BSP patients before treatment.Support vector machine(SVM)is used to distinguish BSP patients from healthy people,and support vector regression(SVR)is used to explore brain changes that can predict the treatment effect of BSP patients.Rusult:Compared to the healthy control group,the ReHo values of the right temporal pole/fusiform gyrus,the left inferior cerebellar lobe,the left middle temporal/inferior temporal gyrus and the left angular gyrus were all increased in the BSP group before treatment.The Reho value of abnormal brain regions in BSP patients after botulinum toxin type A treatment was decreased compared with that before treatment.And the ReHo value of the left inferior cerebellar lobe(p=0.026)and the left middle temporal/inferior temporal gyrus(p=0.028)decreased statistically.According to Pearson correlation analysis,there is no correlation between the ReHo value of different brain regions and the severity of the patient’s disease symptoms.After SVM analysis,the ReHo value of the right temporal pole/fusiform gyrus and the left middle temporal/inferior temporal gyrus can be used as potential biomarkers to distinguish BSP patients from healthy people(The accuracy,sensitivity and specificity were 95%,89%and 100%,respectively).After SVR analysis,the ReHo value of the left lower cerebellum change can predict the therapeutic effect of BSP patients.Conclusions:The motor symptoms of BSP may be related to the regulation of the cerebellar-cortical circuit and the brain regions of the default mode network.The abnormal function of the right temporal pole/fusiform gyrus may be a central compensatory change due to the peripheral symptoms of BSP.The ReHo value of the right temporal pole/fusiform gyrus and the left middle temporal/inferior temporal gyrus can be used as a potential biomarker to distinguish BSP patients from healthy individuals.The therapeutic effect of BSP can be predicted by the changes in the ReHo value of the left inferior cerebellum.