Droby Amgad, Fleischer Vinzenz, Carnini Marco, Zimmermann Hilga, Siffrin Volker, Gawehn Joachim, Erb Michael, Hildebrandt Andreas, Baier Bernhard, Zipp Frauke
Department of Neurology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany ; Neuroimage Center (NIC) of the Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University, Mainz, Germany.
Department of Computer Science, Johannes Gutenberg University, Mainz, Germany.
Neuroimage Clin. 2015 Apr 10;8:110-6. doi: 10.1016/j.nicl.2015.03.003. eCollection 2015.
Infratentorial lesions have been assigned an equivalent weighting to supratentorial plaques in the new McDonald criteria for diagnosing multiple sclerosis. Moreover, their presence has been shown to have prognostic value for disability. However, their spatial distribution and impact on network damage is not well understood. As a preliminary step in this study, we mapped the overall infratentorial lesion pattern in relapsing-remitting multiple sclerosis patients (N = 317) using MRI, finding the pons (lesion density, 14.25/cm(3)) and peduncles (13.38/cm(3)) to be predilection sites for infratentorial lesions. Based on these results, 118 fiber bundles from 15 healthy controls and a subgroup of 23 patients showing lesions unilaterally at the predilection sites were compared using diffusion tensor imaging to analyze the impact of an isolated infratentorial lesion on the affected fiber tracts. Fractional anisotropy, mean diffusion as well as axial and radial diffusivity were investigated at the lesion site and along the entire fiber tract. Infratentorial lesions were found to have an impact on the fractional anisotropy and radial diffusivity not only at the lesion site itself but also along the entire affected fiber tract. As previously found in animal experiments, inflammatory attack in the posterior fossa in multiple sclerosis impacts the whole affected fiber tract. Here, this damaging effect, reflected by changes in diffusivity measures, was detected in vivo in multiple sclerosis patients in early stages of the disease, thus demonstrating the influence of a focal immune attack on more distant networks, and emphasizing the pathophysiological role of Wallerian degeneration in multiple sclerosis.
在用于诊断多发性硬化症的新麦克唐纳标准中，幕下病变被赋予了与幕上斑块同等的权重。此外，它们的存在已被证明对残疾具有预后价值。然而，它们的空间分布及其对网络损伤的影响尚未得到很好的理解。作为本研究的初步步骤，我们使用磁共振成像（MRI）描绘了复发缓解型多发性硬化症患者（N = 317）的整体幕下病变模式，发现脑桥（病变密度，14.25/cm³）和脑脚（13.38/cm³）是幕下病变的好发部位。基于这些结果，使用扩散张量成像比较了15名健康对照者和23名在好发部位单侧出现病变的患者亚组的118条纤维束，以分析孤立的幕下病变对受影响纤维束的影响。在病变部位以及整个纤维束上研究了分数各向异性、平均扩散率以及轴向和径向扩散率。发现幕下病变不仅对病变部位本身而且对整个受影响的纤维束的分数各向异性和径向扩散率都有影响。正如先前在动物实验中所发现的，多发性硬化症患者后颅窝的炎症攻击会影响整个受影响的纤维束。在此，通过扩散率测量变化所反映的这种损伤效应在疾病早期的多发性硬化症患者体内被检测到，从而证明了局灶性免疫攻击对更远网络的影响，并强调了华勒氏变性在多发性硬化症中的病理生理作用。
