Hanakita Shunya, Oya Soichi, Matsui Toru
Department of Neurosurgery, Saitama Medical Center, Saitama Medical University, Kawagoe, Saitama, Japan.
Surg Neurol Int. 2021 Feb 10;12:45. doi: 10.25259/SNI_734_2020. eCollection 2021.
We present a rare case of trigeminal neuralgia (TN) caused by an arachnoid cyst (AC) in Meckel's cave (MC).
A 35-year-old man presented with facial pain in the left maxillary and mandibular regions. Since the initial magnetic resonance (MR) imaging showed no apparent offending vessels or tumors, the patient was diagnosed with idiopathic TN, for which carbamazepine was initially effective. When his pain worsened, he was referred to our hospital. A slightly asymmetric shape of MC and distorted course of the trigeminal nerve was confirmed on the initial and repeat MR images. His pain was characterized as electric-shock-like pain, which was triggered by touching the face. Under the tentative diagnosis of an AC confined to MC compressing the trigeminal nerve, the exploration of MC through suboccipital craniotomy was performed. Intraoperatively, the AC was identified in the rostral portion of MC. The indentation of the trigeminal nerve was also observed at the orifice of MC, indicating severe compression by the AC. The wall of the AC was fenestrated. The patient's pain was relieved immediately after surgery. Postoperative MR images showed that the course of the trigeminal nerve was straightened. Although our literature review found five similar cases, the size of the AC was the smallest in our case.
Although it is rare, the AC confined to MC can cause TN. The findings of this study emphasize the importance of evaluating subtle radiological findings of compression on the trigeminal nerve in cases of TN seemingly without neurovascular compression.
我们报告一例罕见的由梅克尔腔（MC）内蛛网膜囊肿（AC）引起的三叉神经痛（TN）病例。
一名35岁男性出现左侧上颌和下颌区域面部疼痛。由于最初的磁共振（MR）成像未显示明显的责任血管或肿瘤，该患者被诊断为特发性TN，卡马西平最初对此有效。当他的疼痛加重时，他被转诊至我院。初次及复查MR图像证实MC形状略有不对称以及三叉神经走行扭曲。他的疼痛表现为电击样疼痛，由触摸面部触发。在初步诊断为局限于MC的AC压迫三叉神经的情况下，通过枕下开颅术对MC进行了探查。术中，在MC的头侧部分发现了AC。在MC孔口处也观察到三叉神经有压迹，表明AC存在严重压迫。对AC的壁进行了开窗。术后患者的疼痛立即缓解。术后MR图像显示三叉神经走行变直。尽管我们的文献回顾发现了5例类似病例，但我们病例中的AC尺寸最小。
尽管罕见，但局限于MC的AC可导致TN。本研究结果强调了在看似无神经血管压迫的TN病例中评估三叉神经受压细微影像学表现的重要性。
