Massachusetts Eye and Ear and Infirmary, Harvard Medical School, Boston, Massachusetts 02114, USA.
Otol Neurotol. 2012 Apr;33(3):473-80. doi: 10.1097/MAO.0b013e318248ee02.
Hearing loss is a common symptom in patients with cochleovestibular schwannoma. Clinical and histologic observations have suggested that the hearing loss may be caused by both retrocochlear and cochlear mechanisms. Our goal was to perform a detailed assessment of cochlear pathology in patients with vestibular schwannoma (VS).
Retrospective analysis of temporal bone histopathology.
Multi-center study.
Temporal bones from 32 patients with unilateral, sporadic VS within the internal auditory canal.
Sections through the cochleae on the VS side and opposite (control) ear were evaluated for loss of inner and outer hair cells, atrophy of the stria vascularis, loss of cochlear neurons, and presence of endolymphatic hydrops and precipitate within the endolymph or perilymph. Observed pathologies were correlated to nerve of origin, VS volume, and distance of VS from the cochlea. Hearing thresholds also were assessed.
VS caused significantly more inner and outer hair cell loss, cochlear neuronal loss, precipitate in endolymph and perilymph, and decreased pure tone average, when compared with the opposite ear. Tumor size, distance from the cochlea, and nerve of origin did not correlate with structural changes in the cochlea or the hearing threshold.
There is significant degeneration of cochlear structures in ears with VS. Cochlear dysfunction may be an important contributor to the hearing loss caused by VS and can explain certain clinically observed phenomena in patients with VS.
听力损失是听神经鞘瘤患者的常见症状。临床和组织学观察表明，听力损失可能由耳蜗后和耳蜗机制引起。我们的目标是对前庭神经鞘瘤（VS）患者的耳蜗病理进行详细评估。
回顾性分析颞骨组织病理学。
多中心研究。
来自 32 例单侧、散发性前庭神经鞘瘤患者的颞骨，肿瘤位于内听道内。
对 VS 侧和对侧（对照）耳耳蜗的切片进行评估，以评估内、外毛细胞缺失、血管纹萎缩、耳蜗神经元缺失，以及内淋巴积水和内淋巴或外淋巴中沉淀物的存在。观察到的病理与起源神经、VS 体积以及 VS 与耳蜗的距离相关。还评估了听力阈值。
与对侧耳相比，VS 导致更明显的内、外毛细胞缺失、耳蜗神经元缺失、内淋巴和外淋巴中的沉淀物，以及纯音平均听力下降。肿瘤大小、与耳蜗的距离以及起源神经与耳蜗结构变化或听力阈值无相关性。
VS 侧耳的耳蜗结构有明显退化。耳蜗功能障碍可能是 VS 引起听力损失的重要原因，并可以解释 VS 患者的某些临床观察现象。
