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Reconstructed white matter tracts in healthy subjects (HC) ((right) DST patients (left) and BSP patients (center) overlaid on the MNI152 standard brain). Red-yellow colors mean the extent of spatial overlap of reconstructed tracts between participants; specifically, red indicates at least 50% overlap and yellow indicates 100%. Green areas are the regions of interest used for probabilistic tractography.
Source publication
Dystonia is thought to be a network disorder due to abnormalities in the basal ganglia-thalamo-cortical circuit. We aimed to investigate the white matter (WM) microstructural damage of bundles connecting pre-defined subcortical and cortical regions in cervical dystonia (CD) and blepharospasm (BSP). Thirty-five patients (17 with CD and 18 with BSP)...
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Background
Tourette syndrome (TS) is a neurologic condition characterized by motor and phonic tics. Dystonic tics, including blepharospasm, are considered atypical or unusual in severe TS.
Case Report
We report a severe case of TS with facial dystonic tics resembling blepharospasm in which the microlesion effect and a sustained therapeutic effect...
Citations
... In patients with CD, diffusion tensor imaging (DTI) studies using a region of interest-based analysis or a whole-brain approach have detected extensive WM microstructural changes in the motor cortex, premotor cortex, frontal, temporal and parietal cortices, visual system, basal ganglia, thalamus, cerebellum, and brainstem [8,11]. In addition, DTI studies using tractography-based method demonstrated abnormal connections between the pallidum and brainstem [12], the dentato-rubro-thalamic tract, between the thalamus, middle frontal gyrus and brainstem [13], and between the globus pallidus, putamen, thalamus and the sensorimotor cortices [14]. Therefore, observing abnormalities in DTI studies indicates that diffuse and extensive loss of WM integrity may be a common feature of CD. ...
Background
Accumulating neuroimaging evidence indicates that patients with cervical dystonia (CD) have changes in the cortico-subcortical white matter (WM) bundle. However, whether these patients’ WM structural networks undergo reorganization remains largely unclear. We aimed to investigate topological changes in large-scale WM structural networks in patients with CD compared to healthy controls (HCs), and explore the network changes associated with clinical manifestations.
Methods
Diffusion tensor imaging (DTI) was conducted in 30 patients with CD and 30 HCs, and WM network construction was based on the BNA-246 atlas and deterministic tractography. Based on the graph theoretical analysis, global and local topological properties were calculated and compared between patients with CD and HCs. Then, the AAL-90 atlas was used for the reproducibility analyses. In addition, the relationship between abnormal topological properties and clinical characteristics was analyzed.
Results
Compared with HCs, patients with CD showed changes in network segregation and resilience, characterized by increased local efficiency and assortativity, respectively. In addition, a significant decrease of network strength was also found in patients with CD relative to HCs. Validation analyses using the AAL-90 atlas similarly showed increased assortativity and network strength in patients with CD. No significant correlations were found between altered network properties and clinical characteristics in patients with CD.
Conclusion
Our findings show that reorganization of the large-scale WM structural network exists in patients with CD. However, this reorganization is attributed to dystonia-specific abnormalities or hyperkinetic movements that need further identification.
... Imaging investigations in dystonia have traditionally focused on motor manifestations representing microstructural changes in the cortico-basal ganglia-cerebellar and cortico-striato-pallidothalamic networks, with recent report of involvement of the corticospinal tract and posterior parietal cortex. 10,27 Our study adds to literature due to our focus on imaging correlates of anxiety severity in CD. ...
Background
Anxiety may precede motor symptoms in cervical dystonia (CD) and is associated with an earlier onset of dystonia. Our understanding of anxiety in CD is inadequate.
Objective
To investigate brain networks associated with anxiety in CD.
Methods
Twenty-six subjects with idiopathic CD underwent MRI Brain without contrast. Correlational tractography was derived using Diffusion MRI connectometry. Quantitative Anisotropy (QA) was used in deterministic diffusion fiber tracking. Correlational tractography was then used to correlate QA with State–Trait Anxiety Inventory (STAI) state (STAI-S) and trait (STAI-T) subscales.
Results
Connectometry analysis showed direct correlation between state anxiety and QA in tracts from amygdala to thalamus/ pulvinar bilaterally, and trait anxiety and QA in tracts from amygdala to motor cortex, sensorimotor cortex and parietal association area bilaterally (FDR ≤0.05).
Conclusion
Our efforts to map anxiety to brain networks in CD highlight the role of the amygdala in the pathophysiology of anxiety in CD.
... Previous functional neuroimaging studies on patients with idiopathic BSP have revealed increased cortical activation, 7,8 glucose hypermetabolism, 9,10 decreased amplitude of low-frequency fluctuations, 11,12 decreased functional connectivity profiles in the thalamus 13,14 and abnormal cortico-thalamic circuits. 15,16 Structural neuroimaging studies also revealed commonly changed fractional anisotropy and mean diffusivity in white matter related to the thalamus, [17][18][19] as well as decreased thalamic volume in idiopathic BSP. 20 In contrast, only one study has reported functional changes, 21 and two have reported white matter damage 18,19 in the thalamus in patients with blepharospasm-oromandibular dystonia (BOD). ...
The thalamus is considered a key region in the neuromechanisms of blepharospasm. However, previous studies considered it as a single, homogeneous structure, disregarding potentially useful information about distinct thalamic nuclei. Herein, we aimed to examine (i) whether grey matter volume differs across thalamic subregions/nuclei in patients with blepharospasm and blepharospasm-oromandibular dystonia; (ii) causal relationships among abnormal thalamic nuclei; and (iii) whether these abnormal features can be used as neuroimaging biomarkers to distinguish patients with blepharospasm from blepharospasm-oromandibular dystonia and those with dystonia from healthy controls. Structural MRI data were collected from 56 patients with blepharospasm, 20 with blepharospasm-oromandibular dystonia and 58 healthy controls. Differences in thalamic nuclei volumes between groups and their relationships to clinical information were analysed in patients with dystonia. Granger causality analysis was employed to explore the causal effects among abnormal thalamic nuclei. Support vector machines were used to test whether these abnormal features could distinguish patients with different forms of dystonia and those with dystonia from healthy controls.
Compared with healthy controls, patients with blepharospasm exhibited reduced grey matter volume in the lateral geniculate and pulvinar inferior nuclei, whereas those with blepharospasm-oromandibular dystonia showed decreased grey matter volume in the ventral anterior and ventral lateral anterior nuclei. Atrophy in the pulvinar inferior nucleus in blepharospasm patients and in the ventral lateral anterior nucleus in blepharospasm-oromandibular dystonia patients was negatively correlated with clinical severity and disease duration, respectively. The proposed machine learning scheme yielded a high accuracy in distinguishing blepharospasm patients from healthy controls (accuracy: 0.89), blepharospasm-oromandibular dystonia patients from healthy controls (accuracy: 0.82) and blepharospasm from blepharospasm-oromandibular dystonia patients (accuracy: 0.94). Most importantly, Granger causality analysis revealed that a progressive driving pathway from pulvinar inferior nuclear atrophy extends to lateral geniculate nuclear atrophy and then to ventral lateral anterior nuclear atrophy with increasing clinical severity in patients with blepharospasm. These findings suggest that the pulvinar inferior nucleus in the thalamus is the focal origin of blepharospasm, extending to pulvinar inferior nuclear atrophy and subsequently extending to the ventral lateral anterior nucleus causing involuntary lower facial and masticatory movements known as blepharospasm-oromandibular dystonia. Moreover, our results also provide potential targets for neuromodulation especially deep brain stimulation in patients with blepharospasm and blepharospasm-oromandibular dystonia.
... In patients with CD, diffusion tensor imaging (DTI) studies using a region of interest-based analysis or a whole-brain approach have detected extensive WM microstructural changes in the motor cortex, premotor cortex, frontal, temporal and parietal cortices, visual system, basal ganglia, thalamus, cerebellum, and brainstem [8,11]. In addition, DTI studies using tractography-based method demonstrated abnormal connections between the pallidum and brainstem [12], the dentato-rubrothalamic tract, between the thalamus, middle frontal gyrus and brainstem [13], and between the globus pallidus, putamen, thalamus and the sensorimotor cortices [14]. Therefore, observing abnormalities in DTI studies indicates that diffuse and extensive loss of WM integrity may be a common feature of CD. ...
Background
Accumulating neuroimaging evidence indicates that patients with cervical dystonia (CD) have changes in the cortico-subcortical white matter (WM) bundle. However, whether these patients’ WM structural networks undergo reorganization remains largely unclear. We aimed to investigate topological changes in large-scale WM structural networks in patients with CD compared to healthy controls (HCs), and explore the network changes associated with clinical manifestations.
Methods
Diffusion tensor imaging (DTI) was conducted in 30 patients with CD and 30 HCs, and WM network construction was based on the BNA-246 atlas and deterministic tractography. Based on the graph theoretical analysis, global and local topological properties were calculated and compared between patients with CD and HCs. In addition, the relationship between abnormal topological properties and clinical characteristics was analyzed.
Results
Compared with HCs, patients with CD showed changes in network segregation and resilience, characterized by increased local efficiency and assortativity, respectively. In addition, a significant decrease of network strength was also found in CD patients relative to HCs. No significant correlations were found between altered network properties and clinical characteristics in patients with CD.
Conclusion
Our findings show that extensive reorganization of the large-scale WM structural network exists in patients with CD. However, this reorganization is attributed to dystonia-specific abnormalities or hyperkinetic movements that need further identification.
