Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
Br J Neurosurg. 2024 Oct;38(5):1174-1179. doi: 10.1080/02688697.2022.2154749. Epub 2023 Jan 13.
An arachnoid web is a pathological formation of the arachnoid membrane. It is a rare phenomenon but is known to lead to syrinx formation in the spinal cord along with pain and neurological deficits. On imaging, the 'scalpel sign' is pathognomonic for an arachnoid web. The etiology of syrinx formation from an arachnoid web is currently unknown. This report documents the only two cases of arachnoid webs with an extensive syrinx in which a likely pathophysiologic mechanism is identified. Both cases presented with motor deficits. The patients had no history of trauma or infection. After extensive workup in both patients and observation of the scalpel sign an arachnoid web was suspected. In both cases, the patients were treated surgically after an arachnoid web was suspected. Intra-operative ultrasound visualized in both cases demonstrates a fenestration in the web that allowed passage of cerebrospinal fluid in a rostral-caudal direction due to a ball-valve effect.
蛛网膜-web 是蛛网膜的一种病理性形成。它是一种罕见的现象，但已知它会导致脊髓中的脊髓空洞形成，同时伴有疼痛和神经功能缺损。在影像学上，“手术刀征”是蛛网膜-web 的特征性表现。蛛网膜-web 引起脊髓空洞形成的病因目前尚不清楚。本报告记录了仅有的两例蛛网膜-web 伴广泛脊髓空洞的病例，其中确定了一种可能的病理生理机制。两例患者均表现为运动功能障碍。患者无外伤或感染史。在对两名患者进行广泛检查并观察到手术刀征后，怀疑存在蛛网膜-web。在这两种情况下，在怀疑存在蛛网膜-web 后，均对患者进行了手术治疗。术中超声在两种情况下均显示，由于球阀效应，web 中有一个孔，允许脑脊液沿颅尾方向通过。
