Comparison of neuroimaging topological properties of Meige's syndrome with hemifacial spasm

1713 

Abstract Submission 

Hao Chen¹, Ying Wang², Kexue Deng², Yingxing Zhang³

¹The First Affiliated Hospital of USTC, Hefei, Hefei, ²The First Affiliated Hospital of USTC, Hefei, Anhui, ³Anhui Hospital Affiliated to Children’s Hospital of Fudan University/Anhui Children’s Hospital, Hefei, China

Hao Chen  
The First Affiliated Hospital of USTC
Hefei, Hefei

Ying Wang  
The First Affiliated Hospital of USTC
Hefei, Anhui

Kexue Deng  
The First Affiliated Hospital of USTC
Hefei, Anhui

Yingxing Zhang  
Anhui Hospital Affiliated to Children’s Hospital of Fudan University/Anhui Children’s Hospital
Hefei, China

Meige's syndrome is one of the focal dystonic movement disorders, mainly characterized by bilateral blepharospasm and symmetrical and irregular contraction of oral and facial muscles(Hirono et al. 2014). Hemifacial spasm (HFS) is another kind of dystonia disorder with different clinical manifestations, which is often characterized by a unilateral twitch of the face(Brimley and Sampath 2021). Microvascular decompression is a commonly used method for the radical treatment of HFS(Joo et al. 2022), but there is no ideal treatment for Meige. Investigation of the differences in the neural basis of the two forms of dystonia might give us the inspiration to understand these diseases, which might further help with improving the treatment. Based on previous findings on the neural basis of both diseases, we hypothesized changed role of the frontal regions in the motor network might be related to the etiology of Meige and the main difference between these two disorders. The present study aimed to estimate the differences in terms of functional connectivity between Meige's syndrome and the HFS.

Nineteen unilateral HFS patients (57.26±4.17 years, 13 females) and 15 Meige's syndrome patients (58.67±6.89 years, 10 females) were recruited in this study. All participants were right-handed with no major psychiatric disorders or neurological illnesses.
All participants underwent MRI scanning on a GE 3.0T magnetic resonance scanner (GE, 750W). Resting-state MRI data with 242 frames were acquired with a T2*-weighted echo-planar imaging sequence (TE=30ms, TR=2000ms, FOV=240mm, matrix=64×64, flip angle=85°) with 33 axial slices (no gaps, voxel size: 3.6×3.6×3.6mm ³) covering the whole brain. Corresponding high-resolution T1-weighted three-dimensional gradient-echo (for stereotaxic transformation) images were also collected (TR=1900ms; TE=2.26ms; TI=900ms; 1mm isotropic voxel; 250mm field of view).
Resting-state fMRI data processing was conducted with AFNI (version AFNI_19.0.24, pre-compiled binary linux_ubuntu_16_64). To analyze the rsFC, we adopted the Anatomical Automatic Labeling (AAL) template, a brain atlas system including 90 regions of interest (ROIs) covering all the brain regions of cerebral cortex(Tzourio-Mazoyer et al. 2002). For each participant, the time-course of each ROI was extracted, and the corresponding degree centrality(Cd) and betweenness centrality(BC) of each ROI were computed.
BC refers to the ratio of the shortest path that passes through a point and connects the two points to the total number of shortest path lines between the two nodes in the network(Verbavatz and Barthelemy 2022). Cd is a simple count of the total number of connections linked to a vertex, which is the most direct measure to describe node centrality in network analysis(Telesford et al. 2011).
For either BC or Cd of all the 90 ROIs, we conducted a group t-test between Meige's patients and the HFS patients. And ROIs with p values were FDR corrected (with mafdr function embedded with Matlab R2022a,) and FDR less than 0.05 were considered as ROIs with significant between-group differences.

There was no significant difference in age (t=−0.69, ρ=0.49) or gender distribution between the HFS and the Meige's syndrome patients, as shown in Fig. 1.
As shown in Fig. 2, Meige's syndrome patients showed higher BC of the right superior frontal cortex and higher Cd of the left superior frontal cortex, the left superior medial frontal cortex, the right superior medial frontal cortex, and the left cerebellum cortex than the HFS patients (FDR correction with FDR value less than 0.05, whose uncorrected ρ< 0.005).

Higher centrality of the frontal and cerebellum cortex might be the topological property difference between Meige's syndrome and HFS, which may help to preliminarily understand the mechanism of and abnormal functional connection in Meige's patients, and further explore better treatment.

Neurodegenerative/ Late Life (eg. Parkinson’s, Alzheimer’s)

Connectivity (eg. functional, effective, structural) ²

fMRI Connectivity and Network Modeling ¹

FUNCTIONAL MRI

Movement Disorder