Division of Psychological Medicine and Clinical Neurosciences, Neuroscience and Mental Health Research Institute, Cardiff University School of Medicine, Cardiff, UK.
Cardiff University Brain Imaging Centre (CUBRIC), Cardiff University, Cardiff, UK.
J Neurol. 2024 Mar;271(3):1416-1427. doi: 10.1007/s00415-023-12086-2. Epub 2023 Nov 23.
Dystonia is a hyperkinetic movement disorder with key motor network dysfunction implicated in pathophysiology. The UK Biobank encompasses > 500,000 participants, of whom 42,565 underwent brain MRI scanning. This study applied an optimized pre-processing pipeline, aimed at better accounting for artifact and improving data reliability, to assess for grey and white matter structural MRI changes between individuals diagnosed with primary dystonia and an unaffected control cohort.
Individuals with dystonia (n = 76) were identified from the UK Biobank using published algorithms, alongside an age- and sex-matched unaffected control cohort (n = 311). Grey matter morphometric and diffusion measures were assessed, together with white matter diffusion tensor and diffusion kurtosis metrics using tractography and tractometry. Post-hoc Neurite Orientation and Density Distribution Imaging (NODDI) was also undertaken for tracts in which significant differences were observed.
Grey matter tremor-specific striatal differences were observed, with higher radial kurtosis. Tractography identified no white matter differences, however segmental tractometry identified localised differences, particularly in the superior cerebellar peduncles and anterior thalamic radiations, including higher fractional anisotropy and lower orientation distribution index in dystonia, compared to controls. Additional tremor-specific changes included lower neurite density index in the anterior thalamic radiations.
Analysis of imaging data from one of the largest dystonia cohorts to date demonstrates microstructural differences in cerebellar and thalamic white matter connections, with architectural differences such as less orientation dispersion potentially being a component of the morphological structural changes implicated in dystonia. Distinct tremor-related imaging features are also implicated in both grey and white matter.
肌张力障碍是一种运动障碍，其关键运动网络功能障碍与发病机制有关。英国生物银行包含超过 50 万名参与者，其中 42565 人接受了脑部 MRI 扫描。本研究应用了优化的预处理管道，旨在更好地解释伪影并提高数据可靠性，以评估原发性肌张力障碍患者与未受影响的对照组个体之间的灰质和白质结构 MRI 变化。
使用已发表的算法从英国生物银行中确定肌张力障碍患者（n=76），并与年龄和性别匹配的未受影响的对照组（n=311）进行匹配。评估灰质形态计量学和扩散测量值，以及使用轨迹和轨迹测量法评估白质扩散张量和扩散峰度指标。对观察到显著差异的轨迹进行了后处理神经丝取向和密度分布成像（NODDI）。
观察到与震颤相关的纹状体灰质差异，表现为更高的径向峰度。轨迹分析未发现白质差异，但节段性轨迹分析发现了局部差异，尤其是在小脑上脚和前丘脑辐射中，包括在肌张力障碍患者中，与对照组相比，各向异性分数更高，取向分布指数更低。其他震颤特异性变化包括前丘脑辐射中的神经丝密度指数降低。
对迄今为止最大的肌张力障碍队列之一的成像数据分析表明，小脑和丘脑白质连接存在微观结构差异，结构差异，如方向分散减少，可能是肌张力障碍中所涉及的形态结构变化的组成部分。灰质和白质中也存在与震颤相关的不同影像学特征。
