Michigan State University College of Veterinary Medicine, Large Animal Clinical Sciences, East Lansing, MI, USA.
Michigan State University College of Veterinary Medicine, Pathobiology and Diagnostic Investigation, East Lansing, MI, USA.
Sci Rep. 2019 Jul 10;9(1):9978. doi: 10.1038/s41598-019-46444-w.
Myodural bridges have been described in various species as connective tissue structures "bridging" small cranio-cervical muscles to the dura. Myodural bridges are thought to stabilize the dural sac during head and neck movements and promote cerebrospinal fluid motion; however, their role in neurological diseases has not yet been established. We report ultrasonographic visualization, necropsy, histopathologic and ultrastructural findings of myodural bridges in horses with hereditary equine regional dermal asthenia (HERDA), an equine model of Ehlers-Danlos syndromes. Five HERDA and 5 control horses were studied. Post-mortem examination and ultrasonographic studies (3 HERDA and 4 controls) demonstrated that the atlanto-occipital and atlanto-axial myodural bridges are dynamic structures "moving" the dura. En block resection of the myodural bridges (4 HERDA and 5 controls) was accomplished and histopathology showed myofiber degeneration in 3 HERDA horses and 1 control. Ultrastructural examination revealed loosely packed collagen fibrils with abnormal orientation in all HERDA horses compared to mild abnormalities in 2 controls. Our study provides necropsy and ultrasonographic evidence of the dynamic aspect of the myodural bridges as dural sac stabilizers. Myodural bridges may be pathologically altered in connective tissue disease as evidenced by the ultrastructural morphology in the HERDA myodural bridge.
肌硬膜桥在各种物种中被描述为连接组织结构，“桥接”小的颅颈肌肉和硬脑膜。肌硬膜桥被认为在头部和颈部运动期间稳定硬脑膜囊，并促进脑脊液运动；然而，它们在神经疾病中的作用尚未确定。我们报告了遗传性马区域性皮肤脆弱症（HERDA）马中肌硬膜桥的超声可视化、尸检、组织病理学和超微结构发现，HERDA 是埃勒斯-当洛斯综合征的马模型。研究了 5 头 HERDA 和 5 头对照马。死后检查和超声研究（3 头 HERDA 和 4 头对照）表明，寰枕和寰枢肌硬膜桥是“移动”硬脑膜的动态结构。对肌硬膜桥进行整块切除（4 头 HERDA 和 5 头对照），组织病理学显示 3 头 HERDA 马和 1 头对照马的肌纤维变性。超微结构检查显示，与 2 头对照的轻度异常相比，所有 HERDA 马的胶原纤维排列异常疏松。我们的研究提供了尸检和超声证据，证明肌硬膜桥作为硬脑膜囊稳定剂的动态方面。肌硬膜桥在结缔组织疾病中可能发生病理性改变，这在 HERDA 肌硬膜桥的超微结构形态中得到了证明。
