Increased Functional Connectivity Coupling With Supplementary Motor Area In Blepharospasm At Rest

Background and purpose: Blepharospasm(BSP)is a common movement disorder mainly manifesting involuntary spasms of eyelids.However,its neural pathogenesis remains unclear.Here we aim to explore the abnormalities of brain function in BSP and to illustrate neural mechanisms by assuming supplementary motor area(SMA)as the entry point.Methods: Resting-state functional magnetic resonance imaging scanning was conducted on 25 patients with BSP and 23 healthy controls.Functional connectivity(FC)in BSP was examined by capitalizing on bilateral supplementary motor area.The relationship between clinical features and saliently changed interregional connections was examined by correlation analyses.Results: Patients showed that the left medial prefrontal cortex(MPFC),left lingual gyrus,right cerebellar crus I and right lingual gyrus/cerebellar crus I had enhanced FC with the left SMA,whereas the right inferior temporal gyrus had enhanced FC with the right SMA relative to controls.FC between the left MPFC and left SMA was positively correlated with symptomatic severity in the patients.Conclusions: The enhanced connectivity between bilateral SMA and multiple brain regions explains the important role of SMA in several brain networks,and its changed functional synchronism with other brain regions might be a pathogenic factor of BSP and a key trigger factor in BSP neurobiology.