Thakar Sumit, Kiran Narayanam Anantha Sai, Hegde Alangar S
Department of Neurosurgery, Sri Sathya Sai Institute of Higher Medical Sciences, Whitefield, Bangalore, India.
J Neurosurg Pediatr. 2011 Sep;8(3):299-302. doi: 10.3171/2011.6.PEDS11219.
Spinal extradural arachnoid cysts (ACs) have an infrequent predilection for the sacrum. As with their counterparts in other regions of the spine, cysts in this location are mostly asymptomatic. Common presentations in symptomatic cases include pain in the low back or perineum, radiculopathy, and sphincteric dysfunction. The authors report a hitherto undescribed presentation in which the predominant symptoms are those related to an associated holocord syrinx. This 15-year-old boy presented with fluctuating, spastic paraparesis and a dissociated sensory loss in the trunk. Admission MR imaging of the spine showed an extradural AC from S-2 to S-4 and a holocord, nonenhancing syrinx. The patient underwent S-2 laminectomy, fenestration of the cyst, and partial excision of its wall. Intradural exploration revealed a normal-looking filum terminale and the absence of any dural communication with the cyst. At a follow-up visit 6 months after surgery, his motor and sensory deficits had resolved. Follow-up MR imaging showed complete resolution of the syrinx in the absence of the sacral AC. This is the first report of a sacral extradural AC causing holocord syringomyelia. Because conventional theories of syrinx formation were not helpful in elucidating this case, a hypothesis is postulated to explain the clinicoradiological oddity.
脊髓硬膜外蛛网膜囊肿（ACs）很少发生于骶骨。与脊柱其他部位的囊肿一样，该部位的囊肿大多无症状。有症状病例的常见表现包括下背部或会阴部疼痛、神经根病和括约肌功能障碍。作者报告了一种迄今未描述的表现，其中主要症状与相关的全脊髓空洞症有关。这名15岁男孩表现为波动性痉挛性双下肢轻瘫和躯干分离性感觉丧失。入院时脊柱磁共振成像显示从S-2至S-4的硬膜外AC和一个全脊髓、无强化的空洞。患者接受了S-2椎板切除术、囊肿开窗术和囊肿壁部分切除术。硬膜内探查显示终丝外观正常，且囊肿与硬膜无任何相通。术后6个月随访时，其运动和感觉障碍已消失。随访磁共振成像显示在骶部AC消失的情况下，空洞完全消失。这是关于骶部硬膜外AC导致全脊髓空洞症的首例报告。由于传统的空洞形成理论无助于阐明该病例，因此提出一个假说来解释这一临床放射学异常情况。
