Ramdhani Ritesh A, Kumar Veena, Velickovic Miodrag, Frucht Steven J, Tagliati Michele, Simonyan Kristina
Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Mov Disord. 2014 Aug;29(9):1141-50. doi: 10.1002/mds.25934. Epub 2014 Jun 12.
Numerous brain imaging studies have demonstrated structural changes in the basal ganglia, thalamus, sensorimotor cortex, and cerebellum across different forms of primary dystonia. However, our understanding of brain abnormalities contributing to the clinically well-described phenomenon of task specificity in dystonia remained limited. We used high-resolution magnetic resonance imaging (MRI) with voxel-based morphometry and diffusion weighted imaging with tract-based spatial statistics of fractional anisotropy to examine gray and white matter organization in two task-specific dystonia forms, writer's cramp and laryngeal dystonia, and two non-task-specific dystonia forms, cervical dystonia and blepharospasm. A direct comparison between both dystonia forms indicated that characteristic gray matter volumetric changes in task-specific dystonia involve the brain regions responsible for sensorimotor control during writing and speaking, such as primary somatosensory cortex, middle frontal gyrus, superior/inferior temporal gyrus, middle/posterior cingulate cortex, and occipital cortex as well as the striatum and cerebellum (lobules VI-VIIa). These gray matter changes were accompanied by white matter abnormalities in the premotor cortex, middle/inferior frontal gyrus, genu of the corpus callosum, anterior limb/genu of the internal capsule, and putamen. Conversely, gray matter volumetric changes in the non-task-specific group were limited to the left cerebellum (lobule VIIa) only, whereas white matter alterations were found to underlie the primary sensorimotor cortex, inferior parietal lobule, and middle cingulate gyrus. Distinct microstructural patterns in task-specific and non-task-specific dystonias may represent neuroimaging markers and provide evidence that these two dystonia subclasses likely follow divergent pathophysiological mechanisms precipitated by different triggers.
众多脑成像研究表明，在不同形式的原发性肌张力障碍中，基底神经节、丘脑、感觉运动皮层和小脑均存在结构变化。然而，对于导致肌张力障碍中临床描述详尽的任务特异性现象的脑部异常，我们的了解仍然有限。我们使用基于体素的形态学分析的高分辨率磁共振成像（MRI）以及基于纤维束空间统计分数各向异性的扩散加权成像，来检查两种任务特异性肌张力障碍形式（书写痉挛和喉肌张力障碍）以及两种非任务特异性肌张力障碍形式（颈部肌张力障碍和眼睑痉挛）中的灰质和白质结构。两种肌张力障碍形式之间的直接比较表明，任务特异性肌张力障碍中特征性的灰质体积变化涉及书写和说话时负责感觉运动控制的脑区，如初级躯体感觉皮层、额中回、颞上/下回、扣带中/后回和枕叶皮层，以及纹状体和小脑（小叶VI-VIIa）。这些灰质变化伴随着运动前皮层、额中/下回、胼胝体膝部、内囊前肢/膝部和壳核中的白质异常。相反，非任务特异性组的灰质体积变化仅局限于左侧小脑（小叶VIIa），而白质改变则见于初级感觉运动皮层、顶下小叶和扣带中回。任务特异性和非任务特异性肌张力障碍中不同的微观结构模式可能代表神经影像学标志物，并提供证据表明这两种肌张力障碍亚类可能遵循由不同触发因素引发的不同病理生理机制。
