Ichimura Shinya, Yoshida Kazunari, Kawase Takeshi
Department of Neurosurgery, Keio University, School of Medicine, 35 Shinano-machi, Shinjukuku, Tokyo 160-8582, Japan.
Acta Neurochir (Wien). 2009 Jun;151(6):575-9. doi: 10.1007/s00701-009-0284-7. Epub 2009 Apr 1.
Hypoglossal schwannomas are very rare tumors that often enlarge the hypoglossal canal and jugular foramen, and erode the bone bridge of the occipital condyle. We compared pre- and postoperative 3D bone CT images and discussed the ideal craniotomy to prevent fracture formation.
Seven patients with hypoglossal schwannomas underwent surgery in our department. Six cases were type B and 1 case was type C. All patients complained of hypoglossal nerve paresis and nuchal pain.
We used the condylar fossa approach for four cases of type B, the lateral suboccipital approach with C1 laminectomy for two cases of type B and extradural transjugular approach for one case of type C. In all cases, the lateral rim of the foramen magnum or the posterior rim of the jugular foramen was not resected at the same time. The intracranial part of the tumor was removed in all type B cases. Radiotherapy was added for the residual tumor. No patient had deformity or fracture of the joint.
Opening the hypoglossal canal and dural incision toward the hypoglossal canal are important for high radicality. However, preservation of the lateral rim of the foramen magnum must be noted to prevent consecutive deformity or fracture of the atlanto-occipital joint.
舌下神经鞘瘤是非常罕见的肿瘤，常使舌下神经管和颈静脉孔扩大，并侵蚀枕髁的骨桥。我们比较了术前和术后的三维骨CT图像，并讨论了预防骨折形成的理想开颅手术方法。
7例舌下神经鞘瘤患者在我科接受手术。6例为B型，1例为C型。所有患者均有舌下神经麻痹和颈部疼痛症状。
4例B型患者采用髁窝入路，2例B型患者采用枕下外侧入路并切除C1椎板，1例C型患者采用硬膜外经颈静脉入路。所有病例均未同时切除枕骨大孔外侧缘或颈静脉孔后缘。所有B型病例均切除了肿瘤的颅内部分。对残留肿瘤进行了放疗。无患者出现关节畸形或骨折。
打开舌下神经管并向舌下神经管切开硬脑膜对提高切除率很重要。然而，必须注意保留枕骨大孔外侧缘，以防止寰枕关节连续畸形或骨折。
