Devine Matthew S, Pannek Kerstin, Coulthard Alan, McCombe Pamela A, Rose Stephen E, Henderson Robert D
Department of Neurology, Royal Brisbane and Women's Hospital, Herston, QLD 4006, Australia ; School of Medicine, The University of Queensland, St. Lucia, QLD 4072, Australia.
School of Medicine, The University of Queensland, St. Lucia, QLD 4072, Australia ; Australian e-Health Research Centre, CSIRO, Digital Productivity & Services Flagship, Royal Brisbane and Women's Hospital, Herston, QLD 4006, Australia.
Neuroimage Clin. 2015 Mar 14;7:782-7. doi: 10.1016/j.nicl.2015.03.006. eCollection 2015.
Limb weakness in amyotrophic lateral sclerosis (ALS) is typically asymmetric. Previous studies have identified an effect of limb dominance on onset and spread of weakness, however relative atrophy of dominant and non-dominant brain regions has not been investigated. Our objective was to use voxel-based morphometry (VBM) to explore gray matter (GM) asymmetry in ALS, in the context of limb dominance. 30 ALS subjects were matched with 17 healthy controls. All subjects were right-handed. Each underwent a structural MRI sequence, from which GM segmentations were generated. Patterns of GM atrophy were assessed in ALS subjects with first weakness in a right-sided limb (n = 15) or left-sided limb (n = 15). Within each group, a voxelwise comparison was also performed between native and mirror GM images, to identify regions of hemispheric GM asymmetry. Subjects with ALS showed disproportionate atrophy of the dominant (left) motor cortex hand area, irrespective of the side of first limb weakness (p < 0.01). Asymmetric atrophy of the left somatosensory cortex and temporal gyri was only observed in ALS subjects with right-sided onset of limb weakness. Our VBM protocol, contrasting native and mirror images, was able to more sensitively detect asymmetric GM pathology in a small cohort, compared with standard methods. These findings indicate particular vulnerability of dominant upper limb representation in ALS, supporting previous clinical studies, and with implications for cortical organisation and selective vulnerability.
肌萎缩侧索硬化症（ALS）患者的肢体无力通常是不对称的。先前的研究已经确定了肢体优势对无力发作和扩散的影响，然而，优势和非优势脑区的相对萎缩情况尚未得到研究。我们的目的是使用基于体素的形态计量学（VBM），在肢体优势的背景下探讨ALS患者灰质（GM）的不对称性。30例ALS患者与17名健康对照者进行了匹配。所有受试者均为右利手。每个人都接受了一次结构MRI扫描序列，并由此生成了GM分割图像。对首次出现右侧肢体无力（n = 15）或左侧肢体无力（n = 15）的ALS患者的GM萎缩模式进行了评估。在每组中，还对原始GM图像和镜像GM图像进行了逐体素比较，以确定半球GM不对称的区域。无论首次肢体无力发生在哪一侧，ALS患者均表现出优势（左侧）运动皮层手部区域的不成比例萎缩（p < 0.01）。仅在右侧肢体无力起病的ALS患者中观察到左侧躯体感觉皮层和颞回的不对称萎缩。与标准方法相比，我们将原始图像与镜像图像进行对比的VBM方案能够更灵敏地在一个小队列中检测到不对称的GM病变。这些发现表明ALS患者优势上肢代表区特别易损，支持了先前的临床研究，并对皮层组织和选择性易损性具有启示意义。
