Wittstock Matthias, Wilde Nora, Grossmann Annette, Kasper Elisabeth, Teipel Stefan
Department of Neurology, University Medicine Rostock, Rostock, Germany.
Institute of Diagnostic and Interventional Radiology, University Medicine Rostock, Rostock, Germany.
Front Neurol. 2020 Mar 6;11:164. doi: 10.3389/fneur.2020.00164. eCollection 2020.
Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disorder predominantly affecting the motor system. In a number of patients, mirror movements (MMs) suggest involvement of transcallosal fiber tracts in conjunction with upper motor neuron involvement. The aim of the study was to elucidate functional and structural alterations of callosal integrity in ALS patients with MMs. Nineteen patients with ALS displaying MMs and 20 controls underwent clinical assessment, transcranial magnetic stimulation (TMS), and diffusion tensor imaging (DTI). TBSS (tract based spatial statistics) was performed. We investigated ipsilateral silent period (iSP) as a measure of transcallosal inhibition, and diffusion changes in the corpus callosum and corticospinal tract (CST) as measure of structural integrity. In ALS patients TMS revealed a longer mean iSP latency than controls. Twelve ALS patients (63.2%) showed loss of iSP, but none of the controls. Using region of interest analysis, fractional anisotropy (FA) values of the CST were significantly lower in ALS patients compared with controls, but diffusion parameters of the corpus callosum did not differ between patients and controls. The lack of diffusion changes in the corpus callosum was confirmed in whole brain tract based statistics, assessing FA as well as mean, radial, and axial diffusivity. There was a significant negative correlation between resting motor threshold and FA values of the CST, but not between iSP and FA of the corpus callosum. In conclusion the study failed to show microstructural changes in the corpus callosum in conjunction with MMs. One possible reason may be that functional disturbance of transcallosal pathways precede microstructural changes in the corpus callosum.
肌萎缩侧索硬化症（ALS）是一种主要影响运动系统的神经退行性疾病。在一些患者中，镜像运动（MMs）提示胼胝体纤维束受累以及上运动神经元受累。本研究的目的是阐明患有MMs的ALS患者胼胝体完整性的功能和结构改变。19例患有MMs的ALS患者和20名对照者接受了临床评估、经颅磁刺激（TMS）和扩散张量成像（DTI）检查，并进行了基于束的空间统计学（TBSS）分析。我们将同侧静息期（iSP）作为胼胝体抑制的指标进行研究，并将胼胝体和皮质脊髓束（CST）的扩散变化作为结构完整性的指标。在ALS患者中，TMS显示平均iSP潜伏期比对照组更长。12例ALS患者（63.2%）出现iSP缺失，而对照组无一例出现。通过感兴趣区分析，与对照组相比，ALS患者CST的分数各向异性（FA）值显著降低，但患者和对照组之间胼胝体的扩散参数没有差异。在全脑基于束的统计分析中，评估FA以及平均、径向和轴向扩散率时，证实了胼胝体缺乏扩散变化。静息运动阈值与CST的FA值之间存在显著负相关，但iSP与胼胝体的FA之间无相关性。总之，该研究未能显示胼胝体与MMs相关的微观结构变化。一个可能的原因可能是胼胝体通路的功能障碍先于胼胝体的微观结构变化。
