Investigation Of Hemifacial Spasm Using Resting-state FMRI And VBM

Hemifacial spasm(HFS)is disease characterized by unilateral,paroxysmal,involuntary movement occurring in the muscles innervated by the ipsilateral facial nerve.The involuntary contractions usually begin in the orbicularis oculi muscle and gradually spread to the other muscles related to facial expression.Since HFS can affect facial appearance,long-standing disease frequently leads to social isolation.Such problems invariably impact the patient’s self-image and satisfaction with various aspects of life.Generally speaking,HFS has been attributed to compression of the facial nerve.However,it is not clear whether the abnormalities of brain function and structure are associated with HFS.In this paper,functional magnetic resonance(fMRI)was used to investigate the brain functional and structural changes of 33 patients with HFS and 33 healthy controls.The results showed that compared with the normal group,the patient with HFS showed both regional homogeneity value and the volume of gray matter were significantly lower than healthy controls in the left cerebellum lobules VI.The region is defined as ROI(region of interest)to further analyze the functional connection and dynamic function of the whole brain.The results showed that the functional connectivity between the ROI and the bilateral middle occipital gyrus,and ROI between the right cuneus were significantly reduced.In addition,the dynamic connectivity between the ROI and the cuneus increased significantly.We have found that the left cerebellum lobules VI is very important for patients with HFS,and it may also affect the function of visual information processing and integration related neural pathways.The HFS patients were also divided into left HFS and the right HFS according to their condition.It was found that the left HFS and the right HFS both had the dysfunction in the left cerebellum lobules VI,indicating that the abnormal lobules VI in the left cerebellum is important for HFS and unrelated to the location of the spastic spasm.In addition,there were some brain regions abnormal and their position is opposite to the position of HFS,which may be associated with the position of HFS.The results of structural studies cannot pass a strictly corrected,which may be due to the limited sample,and preliminary results suggest abnormalities in the lobules VI of the cuneus and left cerebellum.The abnormalities of brain function and structure in left HFS and right HFS needs to be further verified and studied by a larger sample.