From the Cardiff University Brain Research Imaging Centre (C.L.M., D.J., K.G., A.D., C.M.W.T.), Cardiff University; Neuroscience and Mental Health Research Institute (C.L.M., K.J.P.), Division of Psychological Medicine and Clinical Neurosciences, Cardiff University School of Medicine; North Bristol NHS Trust (K.S.-K.), United Kingdom; and Image Sciences Institute (C.M.W.T.), University Medical Center Utrecht, the Netherlands.
Neurology. 2024 Aug 27;103(4):e209695. doi: 10.1212/WNL.0000000000209695. Epub 2024 Aug 7.
Adult-onset idiopathic focal cervical dystonia (AOIFCD) involves abnormal posturing of the cervical musculature and, in some individuals, an associated head tremor. Existing neuroimaging studies have implicated key motor networks. However, measures used to date lack specificity toward underlying pathophysiologic differences. We aim to assess white matter motor pathways for localized, microstructural differences, which may aid in understanding underlying mechanisms.
Individuals diagnosed with AOIFCD and an age- and sex-matched control group were prospectively recruited through the Welsh Movement Disorders Research Network. All participants underwent in-depth clinical phenotyping and MRI (structural and diffusion sequences) using ultra-strong diffusion gradients. Tractography (whole-tract median values) and tractometry (along tract profiling) were performed for key white matter motor pathways assessing diffusion kurtosis imaging (DKI), neurite orientation dispersion and density imaging (NODDI), and standard model parameters. Groups were compared using linear model analysis with Bonferroni multiple comparison correction.
Fifty participants with AOIFCD and 30 healthy control participants were recruited, with 46 with AOIFCD and 30 healthy controls included for analysis (33 without head tremor, 13 with head tremor). Significant differences were observed in the anterior thalamic radiations (lower mid-tract fractional anisotropy [estimate = -0.046, = 3.07 × 10], radial kurtosis [estimate = -0.165, = 1.42 × 10], -intra-axonal signal fraction [estimate = -0.044, = 2.78 × 10], orientation coherence [estimate = -0.043, = 1.64 × 10], higher Orientation Dispersion Index [ODI, estimate = 0.023, = 2.22 × 10]) and thalamopremotor tracts (higher mid-tract mean kurtosis [estimate = 0.064, = 7.56 × 10], lower Neurite Density Index [estimate = 0.062, = 2.1 × 10], higher distal tract ODI [estimate = 0.062, = 3.1 × 10], lower [estimate = -0.1, = 2.3 × 10], and striatopremotor tracts [proximal lower : estimate = -0.075, = 1.06 × 10]). These measures correlated with clinical measures: dystonia duration (right thalamopremotor distal ODI: = -0.9, = 1.29 × 10), psychiatric symptoms (obsessive compulsive symptoms: left anterior thalamic radiation = 0.92, = 2.797 × 10), sleep quality (Sleep Disorders Questionnaire Score: left anterior thalamic radiation ODI: = -0.84, = 4.84 × 10), pain (left anterior thalamic radiation ODI: = -0.89, = 1.4 × 10), and cognitive functioning (paired associated learning task , = 0.94, = 6.68 × 10).
Overall, localized microstructural differences were identified within tracts linking the prefrontal and premotor cortices with thalamic and basal ganglia regions, suggesting pathophysiologic processes involve microstructural aberrances of motor system modulatory pathways, particularly involving intra-axonal and fiber orientation dispersion measures.
成人特发性局灶性颈肌张力障碍（AOIFCD）涉及颈部肌肉的异常姿势，在某些个体中还伴有头部震颤。现有的神经影像学研究表明，关键运动网络涉及其中。然而，迄今为止使用的方法缺乏对潜在病理生理差异的特异性。我们旨在评估白质运动通路的局部细微结构差异，这可能有助于理解潜在机制。
通过威尔士运动障碍研究网络，前瞻性招募确诊为 AOIFCD 的个体和年龄及性别匹配的对照组。所有参与者均接受深入的临床表型评估和 MRI（结构和扩散序列）检查，使用超强扩散梯度。对关键白质运动通路进行轨迹重建（全束中位数）和轨迹测量（沿束廓线分析），评估扩散峰度成像（DKI）、神经丝取向弥散和密度成像（NODDI）和标准模型参数。使用线性模型分析并进行 Bonferroni 多重比较校正，对组间进行比较。
共招募了 50 名 AOIFCD 患者和 30 名健康对照组参与者，其中 46 名 AOIFCD 患者和 30 名健康对照组被纳入分析（33 名无头部震颤，13 名有头部震颤）。在前丘脑辐射（较低的中部束分数各向异性[估计值=-0.046，=3.07×10]、径向峰度[估计值=-0.165，=1.42×10]、-轴内信号分数[估计值=-0.044，=2.78×10]、方向相干性[估计值=-0.043，=1.64×10]和较高的方位离散指数[ODI，估计值=0.023，=2.22×10]）和丘脑运动前束（较高的中部束平均峰度[估计值=0.064，=7.56×10]、较低的神经丝密度指数[估计值=0.062，=2.1×10]、较高的远端束 ODI[估计值=0.062，=3.1×10]、较低的[估计值=-0.1，=2.3×10]和纹状体运动前束[近端束：估计值=-0.075，=1.06×10]）中观察到显著差异。这些测量指标与临床指标相关：肌张力障碍持续时间（右侧丘脑运动前束远端 ODI：= -0.9，=1.29×10）、精神症状（强迫症症状：左侧前丘脑辐射：=0.92，=2.797×10）、睡眠质量（睡眠障碍问卷评分：左侧前丘脑辐射 ODI：= -0.84，=4.84×10）、疼痛（左侧前丘脑辐射 ODI：= -0.89，=1.4×10）和认知功能（配对关联学习任务：=0.94，=6.68×10）。
总体而言，在连接前额叶和运动前皮质与丘脑和基底节区域的束内发现了局部细微结构差异，表明病理生理过程涉及运动系统调节途径的微观结构异常，特别是涉及轴内和纤维方向离散度的测量。
