Mokri B, Parisi J E, Scheithauer B W, Piepgras D G, Miller G M
Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA.
Neurology. 1995 Oct;45(10):1801-7. doi: 10.1212/wnl.45.10.1801.
Intracranial hypotension is a cause of diffuse enhancement of the pachymeninx with gadolinium, which often is associated with subdural fluid collections. We reviewed the results of meningeal biopsy in six patients with intracranial hypotension and diffuse pachymeningeal enhancement to correlate the MRI findings with histopathologic observations and to explain the abnormalities seen on MRI. Grossly, the dura mater was unremarkable in all patients, as were the leptomeninges, except for one patient with prolonged (18 months) intracranial hypotension in whom the arachnoid was thickened and opaque. Microscopically, the dura mater was entirely normal on its epidural aspect; however, a fairly thin zone of fibroblasts and thin-walled small blood vessels in an amorphous matrix was noted on the subdural aspect. In the patient with longstanding symptoms, diffuse benign arachnoidal cell proliferation was also noted, probably a reaction triggered by longstanding changes in the subdural area, as noted in the five other patients. There was no evidence of inflammation, infection, or metastatic neoplasia. These findings suggest that in intracranial hypotension, the dural-meningeal abnormalities probably represent reactive secondary phenomena, likely related to hydrostatic changes in the CSF, and not a primary meningeal process.
颅内低压是钆增强硬脑膜弥漫性强化的一个原因，常与硬膜下积液相关。我们回顾了6例颅内低压伴硬脑膜弥漫性强化患者的脑膜活检结果，以将MRI表现与组织病理学观察结果相关联，并解释MRI上所见的异常情况。大体上，所有患者的硬脑膜均无明显异常，软脑膜也无明显异常，但有1例颅内低压持续18个月的患者，其蛛网膜增厚且不透明。显微镜下，硬脑膜的硬膜外层面完全正常；然而，在硬膜下层面可见一层相当薄的成纤维细胞和薄壁小血管区域，位于无定形基质中。在有长期症状的患者中，还发现了弥漫性良性蛛网膜细胞增生，这可能是由硬膜下区域的长期变化引发的反应，其他5例患者也有类似情况。没有炎症、感染或转移性肿瘤的证据。这些发现表明，在颅内低压中，硬脑膜-脑膜异常可能代表反应性继发现象，可能与脑脊液的流体静力变化有关，而不是原发性脑膜病变。
