Department of Ophthalmology, University of Sydney, Sydney, Australia Department of Ophthalmology, King Saud University, Riyadh, Saudi Arabia.
Concord Hospital, Sydney, Australia Department of Neurology, Royal North Shore Hospital, Sydney, Australia.
Invest Ophthalmol Vis Sci. 2014 May 15;55(6):3758-64. doi: 10.1167/iovs.14-14571.
The aim of the study was to test the hypothesis that latency delay of multifocal visual evoked potentials (mfVEP) in nonoptic neuritis (NON) eyes of multiple sclerosis (MS) patients is related to retrochiasmal demyelinating lesions.
A total of 57 MS patients with no history of optic neuritis at least in one eye, and 25 age- and sex-matched healthy controls was enrolled. Probabilistic tractography was used to reconstruct optic radiation (OR) fibers. The MS lesion volume within and outside of OR was calculated. Diffusion tensor imaging (DTI) indices were measured along OR fibers. The relationship of the mfVEP latency with OR lesions and DTI indices was examined.
Average mfVEP latency in the MS cohort was significantly delayed compared to controls (P < 0.0001). Of the patients, 77% demonstrated OR lesions. Axial, radial, and mean diffusivity were significantly abnormal in MS patients (P < 0.001). Partial correlation demonstrated significant association between mfVEP latency delay and OR lesion load. There was also significant correlation between MfVEP latency and OR DTI. Subgroup analysis revealed significantly higher correlations in patients without a history of ON in either eye compared to the fellow eye of patients with previous ON.
The findings of this study support our hypothesis that latency delay of the mfVEP in eyes of MS patients without previous ON is related to retrogenicular demyelinating lesions. Additionally, this study demonstrated that a previous episode of ON in the fellow eye may be a significant confounding factor, masking the relationship between the latency and OR lesions.
本研究旨在验证这样一个假设，即多发性硬化症（MS）患者无视神经炎（NON）病史的眼的多焦视觉诱发电位（mfVEP）潜伏期延迟与视交叉后脱髓鞘病变有关。
共纳入 57 例至少一只眼无视神经炎病史的 MS 患者和 25 名年龄和性别匹配的健康对照者。采用概率追踪技术重建视辐射（OR）纤维。计算 OR 内和 OR 外的 MS 病变体积。测量 OR 纤维上的弥散张量成像（DTI）指数。检查 mfVEP 潜伏期与 OR 病变和 DTI 指数的关系。
与对照组相比，MS 组的平均 mfVEP 潜伏期明显延迟（P < 0.0001）。患者中有 77%存在 OR 病变。MS 患者的轴向、径向和平均弥散度均明显异常（P < 0.001）。偏相关分析显示 mfVEP 潜伏期延迟与 OR 病变负荷之间存在显著相关性。mfVEP 潜伏期与 OR DTI 之间也存在显著相关性。亚组分析显示，在双眼均无 ON 病史的患者中，相关性显著高于单侧有 ON 病史的患者。
本研究的结果支持我们的假设，即无既往 ON 病史的 MS 患者眼 mfVEP 潜伏期延迟与视交叉后脱髓鞘病变有关。此外，本研究还表明，对侧眼先前发生 ON 可能是一个显著的混杂因素，掩盖了潜伏期与 OR 病变之间的关系。
