Wang Shu-Qi, Li Chen-Long, Xu Jing-Qi, Chen Li-Li, Xie You-Zhou, Dai Pei-Dong, Ren Liu-Jie, Yao Wen-Juan, Zhang Tian-Yu
Department of Facial Plastic Reconstruction Surgery, Eye and ENT Hospital of Fudan University, Shanghai, China.
ENT Institute, Eye and ENT Hospital of Fudan University, Shanghai, China.
Front Cell Neurosci. 2022 Apr 11;16:836093. doi: 10.3389/fncel.2022.836093. eCollection 2022.
Endolymphatic hydrops (EH) is considered as the pathological correlate of Menière's disease (MD) and cause of hearing loss. The mechanism of EH, remaining unrevealed, poses challenges for formalized clinical trials.
This study aims to investigate the development of hearing loss, as well as the effect of dehydration treatment on EH animal models.
In this study, different severity EH animal models were created. The laser Doppler vibrometer (LDV) and auditory brainstem responses (ABR) were used to study the effects of EH and the dehydration effects of mannitol. The LDV was used to measure the vibration of the round window membrane (RWM) reflecting the changes in inner ear impedance. ABR was used to evaluate the hearing changes. Furthermore, tissue section and scanning electron microscopy (SEM) observations were used to analyze the anatomical change to the cochlea and outer hair cells.
The RWM vibrations decreased with the severity of EH, indicating an increase in the cochlear impedance. The dehydration therapy lowered the impedance to restore acoustic transduction in EH 10- and 20-day animal models. Simultaneously, the ABR thresholds increased in EH models and were restored after dehydration. Moreover, a difference in the hearing was found between ABR and LDV results in severe EH animal models, and the dehydration therapy was less effective, indicating a sensorineural hearing loss (SNHL).
Endolymphatic hydrops causes hearing loss by increasing the cochlear impedance in all tested groups, and mannitol dehydration is an effective therapy to restore hearing. However, SNHL occurs for the EH 30-day animal models, limiting the effectiveness of dehydration. Our results suggest the use of dehydrating agents in the early stage of EH.
内淋巴积水（EH）被认为是梅尼埃病（MD）的病理关联因素及听力损失的病因。EH的发病机制尚未明确，这给规范化临床试验带来了挑战。
本研究旨在探讨听力损失的发展情况以及脱水治疗对EH动物模型的影响。
在本研究中，创建了不同严重程度的EH动物模型。使用激光多普勒振动计（LDV）和听觉脑干反应（ABR）来研究EH的影响以及甘露醇的脱水效果。LDV用于测量圆窗膜（RWM）的振动，以反映内耳阻抗的变化。ABR用于评估听力变化。此外，通过组织切片和扫描电子显微镜（SEM）观察来分析耳蜗和外毛细胞的解剖学变化。
RWM振动随EH严重程度的增加而降低，表明耳蜗阻抗增加。脱水疗法降低了阻抗，从而在EH 10天和20天的动物模型中恢复了声传导。同时，EH模型中的ABR阈值升高，脱水后恢复。此外，可以发现严重EH动物模型中ABR和LDV结果在听力方面存在差异，且脱水疗法效果较差，提示存在感音神经性听力损失（SNHL）。
在所有测试组中，内淋巴积水通过增加耳蜗阻抗导致听力损失，甘露醇脱水是恢复听力的有效疗法。然而，EH 30天的动物模型出现了SNHL，限制了脱水的效果。我们的结果提示在EH早期使用脱水剂。
