Structure And Functional Neurofilm Imaging Of Spastic Torticollis

ObjectiveIn order to understand the neuroimaging characteristics of cervical dystonia (CD) and explore the pathogenesis and pathophysiological process of CD, we compare the differences of grey matter density, the integrity of white matter tracts and the activation of neurons in the resting state of CD patients and healthy controls by using voxel-based morphology (VBM), resting-state functional magnetic resonance imaging (Rs-fMRI), as well as diffusion tensor imaging (DTI) comprehensively.MethodsIn the resting state,18 patients with CD and 18 age and sex-matched healthy controls were scanned with 3.0T Discovery MR750 (GE Company). Patients were evaluated by Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and Tsui Rating Scale by examinant. The image data were preprocessed with SPM8、DPARSF、REST、 PANDA、FSL, etc. We use two sample t-test to compare the structural changes of gray matter density, fraction anisotropy (FA) and mean diffusivity (MD) of white matter tracts, and the functional changes of amplitude of low frequency fluctuation (ALFF), regional homogeneity (ReHo) and functional connectivity (FC) between whole brain and cerebellum, sensorimotor network (SMN) and default mode network (DMN) as well. For correlation analysis, we analyzed the correlation between the above-mentioned data and clinical features, including TWSTRS, Tsui score, disease course and symptoms.Results1. VBM results showed that compared with healthy controls, CD patients had significantly reduced gray matter density in bilateral cerebellum and sensory-motor cortex (p<0.05, AlphaSim correction) and increased gray matter density in the cerebellum and right prefrontal cortex (p<0.05, AlphaSim correction);2. ALFF and ReHo results showed that compared with healthy controls, CD patients had significantly enhanced ALFF and ReHo in the DMN area (p<0.05, AlphaSim correction); ReHo was also enhanced in the visual cortex, while was significantly reduced mainly in the primary sensorimotor area (p<0.05, AlphaSim correction);3. FC results showed that compared with healthy controls, no significant findings about FC between whole brain and cerebellum; significantly reduced FC between whole brain and SMN seed was mainly located within SMN (p<0.01, AlphaSim correction); significantly reduced FC between whole brain and DMN seeds was located in left prefrontal cortex, cerebellum, cingulate gyrus and occipital lobe (p<0.05, AlphaSim correction);4. DTI voxel-level analysis showed, significantly reduced FA values were mainly located in the cerebellum, frontal and temporal cortex and limbic system; significantly increased MD values were located in frontal and temporal cortex and limbic system (p<0.05, AlphaSim correction). Map-level analysis showed, FA, MD value changes were mainly located in the cerebellum, brainstem and cingulate gyrus(p<0.05, AlphaSim correction);5. Correlation analysis showed that gray matter density and the posterior cingulate/ precuneus functional connectivity of CD patients were negatively correlated with TWSTRS (p<0.01, AlphaSim correction). And the gray matter density and Tsui score was significantly negatively correlated (p<0.05, AlphaSim correction). No other significant correlation was found.Conclusion1. Gray matter density and integrity of white matter tracts of cerebellum of CD patients is significantly reduced, but there is no significantly reduced functional connectivity between the whole brain and cerebellum;2. There are both structural changes of reduced gray matter density and functional changes of neuron activity in SMN in the patients with CD; while the function of visual cortex might be enchanced in the resting state;3. The increase of gray matter density in the right prefrontal cortex of CD patients may be related to their anxiety states; on the contrary, the functional connectivity of left prefrontal cortex that is associated with positive emotions is weakened;4. The neuron activity within DMN area is increased, but the functional connectivity between whole brain and DMN is reduced;5. CD patients also have structural changes of white matter in the brain stem, especially medial lemniscus.6. Accordingly, the structure and function of sensory motor area and the visual area, the limbic system, cerebellum and brainstem play an important role in the pathogenesis of cervical dystonia.