von dem Hagen Elisabeth A H, Hoffmann Michael B, Morland Antony B
Department of Psychology, University of York, York, United Kingdom.
Invest Ophthalmol Vis Sci. 2008 Jan;49(1):238-49. doi: 10.1167/iovs.07-0458.
To compare VEP and fMRI as a means of detecting the abnormal visual projections in albinism in different stimulation conditions.
Cortical response to monocular full-field pattern-onset and hemifield pattern-onset and -reversal stimulation of 18 subjects with a known diagnosis of albinism, 17 control subjects, and 6 control subjects with infantile nystagmus syndrome (INS) was determined by VEP and fMRI. An asymmetry index was used to quantify the extent of response lateralization as measured by both VEP and fMRI. The extent to which each method and stimulus combination differentiated participant groups was summarized with a receiver operating characteristic (ROC) analysis, where A(A-C) and A(A-N) refer to areas under the ROC curve for albino versus control and albino versus nystagmus comparisons.
Cortical response to full-field monocular stimulation conditions offered robust detection of the abnormal response lateralization in albinism, with fMRI (A(A-C) = 1.00; A(A-N) = 0.91) being slightly more robust than the VEP under these conditions (A(A-C) = 0.91; A(A-N) = 0.79). Hemifield stimulation paradigms were somewhat poorer at differentiating between groups, particularly when VEP was used in combination with pattern-reversal stimulation (pattern-onset fMRI A(A-C) = 0.94, A(A-N) = 0.84, and VEP A(A-C) = 0.86, A(A-N) = 0.86; pattern-reversal fMRI A(A-C) = 0.90, A(A-N) = 0.88, and VEP A(A-C) = 0.69, A(A-N) = 0.64). However, when only the most posterior aspects of the occipital lobe were considered with hemifield stimulation, fMRI achieved the best differentiation between the subject groups, most notably with hemifield pattern-reversal stimulation (A(A-C) = 1.00; A(A-N) = 1.00).
An interocular comparison between the lateralization of cortical responses elicited by full-field stimulation reliably distinguished between those with albinism and control groups, when both fMRI and VEP were used to assess cortical responses. Hemifield stimulation of one eye offers an alternative method for assessing misrouting associated with albinism and is highly effective when cortical signals are assessed with fMRI, but less so when VEP is used.
比较视觉诱发电位（VEP）和功能磁共振成像（fMRI）在不同刺激条件下检测白化病异常视觉投射的能力。
通过VEP和fMRI测定18例已知诊断为白化病的受试者、17例对照受试者以及6例患有婴儿型眼球震颤综合征（INS）的对照受试者对单眼全视野图形起始、半视野图形起始和图形反转刺激的皮质反应。使用不对称指数来量化通过VEP和fMRI测量的反应偏侧化程度。通过受试者工作特征（ROC）分析总结每种方法和刺激组合区分参与者组的程度，其中A（A - C）和A（A - N）分别指白化病与对照以及白化病与眼球震颤比较的ROC曲线下面积。
在全视野单眼刺激条件下，皮质反应能够可靠地检测到白化病患者异常的反应偏侧化，在这些条件下，fMRI（A（A - C） = 1.00；A（A - N） = 0.91）比VEP稍强（A（A - C） = 0.91；A（A - N） = 0.79）。半视野刺激模式在区分组间差异方面稍差，特别是当VEP与图形反转刺激联合使用时（图形起始fMRI A（A - C） = 0.94，A（A - N） = 0.84，VEP A（A - C） = 0.86，A（A - N） = 0.86；图形反转fMRI A（A - C） = 0.90，A（A - N） = 0.88，VEP A（A - C） = 0.69，A（A - N） = 0.64）。然而，当在半视野刺激时仅考虑枕叶最后部时，fMRI在受试者组间实现了最佳区分，最显著的是在半视野图形反转刺激时（A（A - C） = 1.00；A（A - N） = 1.00）。
当使用fMRI和VEP评估皮质反应时，全视野刺激引起的皮质反应偏侧化的双眼间比较能够可靠地区分白化病患者和对照组。单眼半视野刺激为评估与白化病相关的神经通路异常提供了一种替代方法，当用fMRI评估皮质信号时非常有效，但使用VEP时效果较差。
