Boezaart André P, Server Anna, Tubbs Richard Shane, Carrera Ana, Reina Francisco, Reina Miguel A
Department of Anesthesiology, University of Florida College of Medicine, Gainesville, Florida, USA.
Lumina Health, Surrey, UK.
Clin Anat. 2025 Apr;38(3):269-277. doi: 10.1002/ca.24228. Epub 2024 Sep 18.
In infectious meningitis, pathogens preferentially attack the leptomeninges (pia mater and arachnoid) rather than the pachymeninges (dura mater). This study aims to provide ultra-anatomical insights from our extensive collection of electron microscopy images and propose mechanisms, highlighting structures that favor the introduction, adherence, colonization, and proliferation of microorganisms leading to spinal meningitis. Over several years, we analyzed an extensive collection of transmission and scanning electron microscopy images of human spinal meninges captured in our laboratories. Upon examining 378 of those images, we identified potential sites for the iatrogenic or hematogenic introduction and adherence of microorganisms, as well as sites for their colonization and proliferation. These included the outer surface of the spinal dural sac, structures within the epidural space, and the spinal dural sac itself, which comprises compact dura mater with interwoven collagen fibers and tightly bound arachnoid cells. Also, the subdural (extra-arachnoid) compartment, consisting of fragile neurothelial cells prone to rupture under force, formed an acquired spinal subdural space, a new subarachnoid compartment, limited by arachnoid trabeculae, that surrounded the nerve roots and spinal cord and the pia mater. Macrophages, fibroblasts, mast cells, and plasma cells were also observed within the dura mater, arachnoid layer, arachnoid trabeculae, and pia mater. These images illustrate how the characteristics of the meningeal layers could contribute to bacterial adhesion and proliferation at various locations, inducing selective inflammation during (iatrogenic) spinal meningitis. In addition, the images help to explain why magnetic resonance imaging enhancement appears preferentially at specific sites.
在感染性脑膜炎中，病原体优先侵袭软脑膜（蛛网膜和软膜）而非硬脑膜。本研究旨在通过我们大量的电子显微镜图像集提供超微解剖学见解，并提出相关机制，突出有利于导致脊髓膜炎的微生物引入、黏附、定植和增殖的结构。多年来，我们分析了在我们实验室采集的大量人类脊髓膜的透射和扫描电子显微镜图像。在检查其中378张图像时，我们确定了微生物医源性或血源性引入和黏附的潜在部位，以及它们定植和增殖的部位。这些部位包括脊髓硬膜囊的外表面、硬膜外间隙内的结构以及脊髓硬膜囊本身，脊髓硬膜囊由交织的胶原纤维和紧密结合的蛛网膜细胞组成的致密硬脑膜构成。此外，由脆弱的神经上皮细胞组成的硬脑膜下（蛛网膜外）腔隙在受力时容易破裂，形成了一个后天性脊髓硬脑膜下腔隙，这是一个新的蛛网膜下腔隙，由蛛网膜小梁限制，围绕神经根、脊髓和软膜。在硬脑膜、蛛网膜层、蛛网膜小梁和软膜内也观察到巨噬细胞、成纤维细胞、肥大细胞和浆细胞。这些图像说明了脑膜各层的特征如何在不同位置促进细菌黏附和增殖，在（医源性）脊髓膜炎期间引发选择性炎症。此外，这些图像有助于解释为什么磁共振成像增强优先出现在特定部位。
