Optic nerve diffusion changes and atrophy jointly predict visual dysfunction after optic neuritis
Optic nerve diffusion changes and atrophy jointly predict visual dysfunction after optic neuritis
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DOI：
10.1016/j.neuroimage.2008.12.047
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发表时间：
2009-04-15
期刊：
影响因子：
5.7
通讯作者：
Egan, Gary
中科院分区：
文献类型：
--
作者：
Kolbe, Scott;Chapman, Caron;Egan, Gary
最近，人们对影像学技术的发展产生了浓厚的兴趣，以量化多发性硬化症（MS）患者的轴突和髓鞘病理。视神经炎是一种以视神经炎性脱髓鞘为特征的疾病，是多发性硬化症最常见的复发部位之一，其病理改变与中枢神经系统（CNS）其他部位的多发性硬化症病变相似。然而，与中枢神经系统的其他区域不同，视神经的功能可以通过临床测量和电生理技术（如视觉诱发电位记录）来准确评估。因此，视神经炎有助于研究视神经结构异常（MRI）与视觉功能障碍（临床和电生理评估）之间的关系。本研究的目的是利用MRI评估单侧视神经炎病史患者的视神经结构异常，然后确定视神经MRI异常与视觉功能障碍之间的相关性。10名对照组和16名患者接受了高分辨率视神经弥散张量成像（DTI）、T2和t1加权MRI检查。此外，还检测了所有患者的Snellen视敏度和多焦视觉诱发电位（mfVEP）潜伏期和振幅。弥散和体积MRI指标与mfVEP功能指标相关。与未受影响的视神经或健康对照者的视神经相比，在MRI和mfVEP测量中发现了明显的异常。受累侧mfVEP振幅降低与受累视神经萎缩（R=0.58, p=0.02）和分数各向异性（FA）降低（R=0.52, p=0.04）显著相关。然而，萎缩与FA减少之间没有相关性。为了进一步研究这种分离，我们使用线性回归分析，视神经萎缩和视神经FA为自变量，mfVEP振幅为因变量。所得线性回归模型高度显著（R=0.819, p=0.001）。这些结果表明，单侧视神经炎后4年，基于mri的视神经结构异常测量（各向异性和体积下降）独立预测视觉功能障碍。(C) 2009爱思唯尔公司版权所有。
Recently, there has been strong interest in the development of imaging techniques to quantify axonal and myelin pathology in patients with multiple sclerosis (MS). Optic neuritis, a condition characterised by inflammatory demyelination of the optic nerve, is one of the commonest sites of MS relapse, and exhibits similar pathological alterations to MS lesions elsewhere in the central nervous system (CNS). Unlike other regions of the CNS, however, the function of the optic nerve can be accurately assessed using clinical measures, as well as electrophysiological techniques such as visual evoked potential recordings. Therefore, optic neuritis is useful for investigating the relationship between abnormalities in optic nerve structure, assessed using magnetic resonance imaging (MRI), and visual dysfunction, assessed clinically and electrophysiologically. The aims of the present study were to assess optic nerve structural abnormalities in patients with a history of unilateral optic neuritis using MRI, and then to identify correlations between abnormalities in optic nerve MRI and visual dysfunction. Ten controls and sixteen patients underwent high resolution optic nerve diffusion tensor imaging (DTI), T2- and T1-weighted MRI. In addition, Snellen visual acuity and the latency and amplitude of multifocal visual evoked potentials (mfVEP) were tested in all patients. Diffusion and volumetric MRI indices were correlated to mfVEP functional indices. Significant abnormalities were detected in MRI and mfVEP measures in patients' affected nerves compared to unaffected optic nerves or optic nerves from healthy controls. Reduced mfVEP amplitude in the affected side significantly correlated with both affected optic nerve atrophy (R=0.58, p=0.02) and reduced fractional anisotropy (FA) (R=0.52, p=0.04). However, atrophy and reduced FA did not correlate with each other. To further investigate this disassociation, we used linear regression analysis with optic nerve atrophy and optic nerve FA as independent variables and mfVEP amplitude as the dependent variable. The resulting linear regression model was highly significant (R=0.819, p=0.001). These results show that, 4 years after unilateral optic neuritis, MRI-based measures of optic nerve structural abnormalities (decreased anisotropy and volume) independently predict visual dysfunction. (C) 2009 Elsevier Inc. All rights reserved.