Lab of Neural Engineering & Rehabilitation, Department of Biomedical Engineering, College of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China.
ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China; NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200031, China.
Int J Pediatr Otorhinolaryngol. 2021 Jul;146:110752. doi: 10.1016/j.ijporl.2021.110752. Epub 2021 Apr 29.
The purpose of this study was to investigate the effect of a dilated vestibular aqueduct on conductive hearing loss (CHL). A biomechanical method was proposed for modeling the patterns of CHL in patients with large vestibular aqueduct syndrome (LVAS).
High resolution computed tomography (CT) scans and pure tone audiometry (PTA) were retrospectively collected from 16 patients who were diagnosed with LVAS. Seventeen ears with measurable air-bone gaps (ABGs) on PTA were applied for model development. The sizes of midpoint, operculum and distal segment were measured from CT to calculate the biomechanical parameters of each vestibular aqueduct. The mechanical effect of the dilated vestibular aqueduct on sound conduction was simulated using a lumped-parameter model. The CHL levels predicted by the model were compared with the observed ABGs at 250, 500 and 1000 Hz respectively.
The model was able to predict the trend that greater ABGs occurred at lower frequencies, which were consistent with clinical observations. However, deviations between the predicted and the observed ABGs became larger as the frequency increased. None of the correlation coefficients between the radiologic measures and the observed ABG levels were significant.
These findings lend support to the feasibility of this approach in modeling CHL in LVAS. The presence of a dilated vestibular aqueduct leads to altered impedance and sound pressure, suggesting the impact of a pathological third window. High individual variability of the observed ABGs implies additional factors may also be involved, especially at 500 Hz and 1000 Hz.
本研究旨在探讨扩大的前庭导水管对传导性听力损失（CHL）的影响。提出了一种生物力学方法，用于对大前庭水管综合征（LVAS）患者的 CHL 模式进行建模。
回顾性收集了 16 例经诊断为 LVAS 的患者的高分辨率计算机断层扫描（CT）和纯音测听（PTA）。17 只耳朵在 PTA 上有可测量的气骨间隙（ABG），用于模型开发。从 CT 测量中点、镫骨和远端段的大小，以计算每个前庭导水管的生物力学参数。使用集总参数模型模拟扩大的前庭导水管对声音传导的机械影响。将模型预测的 CHL 水平与 250、500 和 1000 Hz 时的观察到的 ABG 进行比较。
该模型能够预测 ABG 在较低频率时更大的趋势，这与临床观察一致。然而，随着频率的增加，预测的 ABG 与观察到的 ABG 之间的偏差越来越大。影像学测量值与观察到的 ABG 水平之间的相关性均无统计学意义。
这些发现支持了该方法在 LVAS 中建模 CHL 的可行性。扩大的前庭导水管导致阻抗和声压改变，提示存在病理性第三窗口的影响。观察到的 ABG 的个体差异很大，这意味着可能还涉及其他因素，尤其是在 500 Hz 和 1000 Hz。
