Suh SY, Clark RA, Le A, et al.
期刊名称：Investigative ophthalmology & visual science
目的：旨在使用磁共振成像（MRI）研究单侧上斜肌（SO）麻痹眼外肌（EOM）腔体积的变化。方法：对19例单侧SO患者和19例年龄匹配的正交对照者进行高分辨率，表面线圈MRI检查。将单侧SO麻痹患者的眼外直肌和SO分为两个解剖间隔进行体积分析，并与对照组的总体积进行比较。比较均质（圆形）与非均质（细长形状）SO萎缩患者上斜肌内侧和外侧分隔体积。结果：均质SO麻痹的损伤侧SO肌内侧和外侧间隔同样萎缩，但非均质SO萎缩的横向萎缩程度明显小于内侧（P = 0.01）。与SO相比，眼外直肌的腔容积変化没有差异；然而，损伤侧下直肌（IR）和外直肌（LR）和对侧上直肌（SR）存在明显的总肌肉肥大。内直肌（MR）和对侧上直肌体积正常。结论：SO麻痹患者的一个亚组表现出侧面，主要是垂直SO的选择性萎缩。上斜肌萎缩与损伤侧IR，损伤侧LR和对侧SR全肌体积变化相关；然而，SO肌肉萎缩与眼外直肌间隔选择性体积变化无关。选择性间隔性SO病理学可能提供解释SO麻痹临床表现一些变异性的解剖学机制。
Purpose:To investigate changes in volumes of extraocular muscle (EOM) compartments in unilateral superior oblique (SO) palsy using magnetic resonance imaging (MRI).Methods:High-resolution, surface-coil MRI was obtained in 19 patients with unilateral SO palsy and 19 age-matched orthotropic control subjects. Rectus EOMs and the SO were divided into two anatomic compartments for volume analysis in patients with unilateral SO palsy, allowing comparison of total compartmental volumes versus controls. Medial and lateral compartmental volumes of the SO muscle were compared in patients with isotropic (round shape) versus anisotropic (elongated shape) SO atrophy.Results:The medial and lateral compartments of the ipsilesional SO muscles were equally atrophic in isotropic SO palsy, whereas the lateral compartment was significantly smaller than the medial in anisotropic SO palsy (P = 0.01). In contrast to the SO, there were no differential compartmental volume changes in rectus EOMs; however, there was significant total muscle hypertrophy in the ipsilesional inferior rectus (IR) and lateral rectus (LR) muscles and contralesional superior rectus (SR) muscles. Medial rectus (MR) volume was normal both ipsi- and contralesionally.Conclusions:A subset of patients with SO palsy exhibit selective atrophy of the lateral, predominantly vertically acting SO compartment. Superior oblique atrophy is associated with whole-muscle volume changes in the ipsilesional IR, ipsilesional LR, and contralesional SR; however, SO muscle atrophy is not associated with compartmentally selective volume changes in the rectus EOMs. Selective compartmental SO pathology may provide an anatomic mechanism that explains some of the variability in clinical presentations of SO palsy.