International Neuroscience Institute, Hannover, Germany.
University Multiprofile Hospital for Active Treatment With Emergency Medicine N. I. Pirogov, Sofia, Bulgaria.
Adv Exp Med Biol. 2023;1405:331-362. doi: 10.1007/978-3-031-23705-8_12.
Schwannomas are benign tumors originating from the Schwann cells of cranial or spinal nerves. The most common cranial schwannomas originate from the eight cranial nervevestibular schwannomas (VS). VS account for 6-8% of all intracranial tumors, 25-33% of the tumors localized in the posterior cranial fossa, and 80-94% of the tumors in the cerebellopontine angle (CPA). Schwannomas of other cranial nerves/trigeminal, facial, and schwannomas of the lower cranial nerves/are much less frequent. According to the World Health Organization (WHO), intracranial and intraspinal schwannomas are classified as Grade I. Some VS are found incidentally, but most present with hearing loss (95%), tinnitus (63%), disequilibrium (61%), or headache (32%). The neurological symptoms of VSs are mainly due to compression on the surrounding structures, such as the cranial nerves and vessels, or the brainstem. The gold standard for the imaging diagnosis of VS is MRI scan. The optimal management of VSs remains controversial. There are three main management options-conservative treatment or "watch-and-wait" policy, surgical treatment, and radiotherapy in all its variations. Currently, surgery of VS is not merely a life-saving procedure. The functional outcome of surgery and the quality of life become issues of major importance. The most appropriate surgical approach for each patient should be considered according to some criteria including indications, risk-benefit ratio, and prognosis of each patient. The approaches to the CPA and VS removal are generally divided in posterior and lateral. The retrosigmoid suboccipital approach is a safe and simple approach, and it is favored for VS surgery in most neurosurgical centers. Radiosurgery is becoming more and more available nowadays and is established as one of the main treatment modalities in VS management. Radiosurgery (SRS) is performed with either Gamma knife, Cyber knife, or linear accelerator. Larger tumors are being increasingly frequently managed with combined surgery and radiosurgery. The main goal of VS management is preservation of neurological function - facial nerve function, hearing, etc. The reported recurrence rate after microsurgical tumor removal is 0.5-5%. Postoperative follow-up imaging is essential to diagnose any recurrence.
神经鞘瘤是起源于颅神经或脊神经施万细胞的良性肿瘤。最常见的颅神经鞘瘤起源于第八颅神经前庭神经鞘瘤（VS）。VS 占所有颅内肿瘤的 6-8%，占后颅窝肿瘤的 25-33%，占桥小脑角（CPA）肿瘤的 80-94%。其他颅神经/三叉神经、面神经和颅神经/颅神经的神经鞘瘤则少见得多。根据世界卫生组织（WHO）的分类，颅内和椎管内神经鞘瘤被归类为 I 级。一些 VS 是偶然发现的，但大多数表现为听力损失（95%）、耳鸣（63%）、平衡障碍（61%）或头痛（32%）。VS 的神经症状主要是由于周围结构受压，如颅神经和血管，或脑干。VS 的影像学诊断的金标准是 MRI 扫描。VS 的最佳治疗方案仍存在争议。主要有三种治疗选择——保守治疗或“观察等待”策略、手术治疗和各种形式的放射治疗。目前，VS 的手术不仅仅是一种挽救生命的程序。手术的功能结果和生活质量成为非常重要的问题。应根据一些标准考虑每位患者最合适的手术方法，包括每个患者的适应证、风险-效益比和预后。对于每个患者，应根据一些标准考虑最合适的手术方法，包括每个患者的适应证、风险-效益比和预后。对于 CPA 和 VS 切除术的入路通常分为后入路和外侧入路。乙状窦后枕下入路是一种安全简单的方法，在大多数神经外科中心，它是 VS 手术的首选方法。放射外科技术现在越来越普及，已成为 VS 治疗的主要方法之一。放射外科（SRS）是用伽玛刀、Cyber knife 或直线加速器进行的。较大的肿瘤越来越多地采用手术联合放射外科治疗。VS 治疗的主要目标是保留神经功能——面神经功能、听力等。显微镜下肿瘤切除后的复发率为 0.5-5%。术后随访影像学检查对于诊断任何复发至关重要。
