Division of Otolaryngology--Head & Neck Surgery, Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada.
Neurosurgery. 2011 Jan;68(1):68-77. doi: 10.1227/NEU.0b013e3181fc60cb.
Intracanalicular vestibular schwannomas have a range of treatment options that can preserve hearing: microsurgery, stereotactic radiotherapy, and conservative observation.
To evaluate the natural course of hearing deterioration during a period of conservative observation.
A retrospective case review was performed on 47 patients with a unilateral intracanalicular vestibular schwannoma. Evaluation of growth was monitored by repeat MRI scanning. Repeated pure-tone and speech audiometry results were evaluated for subgroups of patients showing growth or no growth and by subsite location of tumor in the internal auditory canal.
Patients had a mean follow-up of 3.6 years. Over the entire population, the pure-tone average thresholds at 0.5, 1, 2, and 3 kHz and the word recognition scores both significantly deteriorated from 38 to 51 dB HL, and from 66% to 55%, respectively. Overall, 74% of subjects with good hearing, according to the 50/50 rule, maintained hearing above this rule. There were no significant differences in hearing loss by subsite in the internal auditory canal (porus, fundus, central) or by growth status (stable, growing, shrinking). Only 6 patients showed a large hearing change. This happened early during follow-up, with relatively stable hearing after this.
Hearing will deteriorate in some intracanalicular vestibular schwannomas, regardless of tumor growth. Hearing deterioration, if on a large scale, most likely occurs early in follow-up. The present results using conservative management in these tumors appear similar to those reported for stereotactic radiotherapy or microsurgery.
管内前庭神经鞘瘤有多种治疗方案可供选择，可保留听力：显微外科手术、立体定向放射治疗和保守观察。
评估保守观察期间听力恶化的自然病程。
对 47 例单侧管内前庭神经鞘瘤患者进行回顾性病例回顾。通过重复 MRI 扫描监测生长情况。对有生长或无生长的患者亚组和肿瘤在内耳内听道的亚部位位置，评估重复纯音和言语测听结果。
患者的平均随访时间为 3.6 年。在整个人群中，0.5、1、2 和 3 kHz 的纯音平均阈值和言语识别率均从 38dBHL 显著恶化至 51dBHL，分别从 66%下降至 55%。总体而言，根据 50/50 规则，74%的听力良好的受试者（50/50 规则）保持听力在该规则以上。在内耳内听道（孔、底部、中央）或生长状态（稳定、生长、缩小）的亚部位，听力损失无显著差异。只有 6 例患者听力变化较大。这发生在随访早期，此后听力相对稳定。
一些管内前庭神经鞘瘤的听力会恶化，而与肿瘤生长无关。如果听力恶化规模较大，很可能在随访早期发生。本研究采用保守治疗这些肿瘤的结果与立体定向放射治疗或显微外科手术报告的结果相似。
