Department of Ophthalmology and Visual Sciences (THO, GRG, MHO, TO, RB), Paulista School of Medicine/EPM, Federal University of São Paulo/UNIFESP, São Paulo, Brazil; and Laboratory of Molecular and Cellular Biology (GRG, EDC, SKNM), Department of Neurology, University of São Paulo/USP, São Paulo, Brazil.
J Neuroophthalmol. 2023 Sep 1;43(3):410-416. doi: 10.1097/WNO.0000000000001770. Epub 2022 Nov 25.
Subtle morphological alterations have been reported even in the nonaffected side of the orbicularis oculi muscle in patients with hemifacial spasm. However, no previous study assessed immunohistochemical, metabolic, and morphometric alterations in orbicularis oculi muscle fibers in affected and nonaffected sides in patients with this condition, compared with samples obtained from healthy subjects. The purpose of this study is to objectively assess and compare orbicularis oculi muscle (OOM) samples of hemifacial spasm affected and nonaffected sides and healthy subjects.
Orbicularis oculi samples from 8 patients with hemifacial spasm who had not been previously treated and 6 healthy subjects were prepared using hematoxylin and eosin, nicotinamide adenine dinucleotide tetrazolium reductase, cytochrome oxidase, succinate dehydrogenase, Gomori staining, and monoclonal antibodies against myosin slow and myosin fast. A digital image analysis software was used for objective analysis.
OOM fiber area was significantly greater in both affected ( P = 0.0379) and nonaffected sides ( P = 0.0012) of HFS samples when compared with control subjects' fibers. A significantly greater number of oxidative fibers were observed in both affected and nonaffected sides of patients with HFS when compared with control subjects ( P < 0.001 for both). A significantly greater percentage of slow fibers was observed in the affected side of HFS patients ( P = 0.0012) compared with control subjects.
This study's findings suggest that repeated contractions might lead to OOM fiber hypertrophy, increased mitochondrial metabolism, and possible conversion of fast-twitch orbicularis oculi muscle fibers into slow-twitch fibers in patients with HFS. Alterations were observed in affected and nonaffected sides, confirming initial findings that the nonaffected side is not normal in this unique condition.
即使在面肌痉挛患者的眼轮匝肌未受累侧也已报道存在细微的形态改变。然而，既往研究尚未评估过与健康对照组相比，在面肌痉挛患者受累侧和未受累侧眼轮匝肌纤维的免疫组化、代谢和形态计量学改变。本研究旨在客观评估和比较面肌痉挛患者受累和未受累侧及健康对照组的眼轮匝肌（OOM）样本。
本研究纳入 8 例未经治疗的面肌痉挛患者和 6 例健康对照者的眼轮匝肌样本，采用苏木精-伊红、烟酰胺腺嘌呤二核苷酸四唑还原酶、细胞色素氧化酶、琥珀酸脱氢酶、Gomori 染色和抗肌球蛋白慢型和肌球蛋白快型的单克隆抗体进行处理。采用数字图像分析软件进行客观分析。
与健康对照组相比，面肌痉挛患者受累侧（P = 0.0379）和未受累侧（P = 0.0012）的 OOM 纤维面积显著增加。与健康对照组相比，面肌痉挛患者受累侧和未受累侧的氧化纤维数量显著增加（均 P < 0.001）。与健康对照组相比，面肌痉挛患者受累侧的慢肌纤维比例显著增加（P = 0.0012）。
本研究结果表明，反复收缩可能导致 OOM 纤维肥大、线粒体代谢增加，以及面肌痉挛患者的快型眼轮匝肌纤维可能转化为慢型纤维。受累侧和未受累侧均存在改变，证实了未受累侧在这种独特疾病中并非正常的初步发现。
