Engström B
Scand Audiol Suppl. 1983;19:1-34.
The aim of the present study was to investigate specific structural alterations in the cochlea of ears with sensory neural hearing loss and to determine the relation between structural damage and loss of auditory function. The results show that with the methods used in this study it is possible to obtain well preserved structures with consistent morphological characteristics. Examination and identification of small pathological alterations were thus possible. The stereocilia of the IHCs were found by scanning electron microscopy to be the structure most susceptible to damage by noise in the rabbit. The extent of IHC damage corresponded rather well with the frequency range for loss of auditory function, particularly threshold shift of the MER. The damage of the IHCs consisted of fusion, fracture and inclination of the stereocilia towards the OHCs. The OHC were frequently left unaltered even when the stereocilia of most IHCs exhibited pronounced alterations. In animals with a severe hearing loss and a postexposure time of more than two months, long "giant" cilia and often also a small thin kinocilium were found on the IHCs. IHC ciliary damage was found also in other species including man, but to a smaller extent than in the rabbit. The stereocilia of IHCs were also damaged by noise in ears of rabbits where the OHCs had been experimentally removed prior to the noise exposure. It was concluded that stereocilia damage is an important morphological alteration in ears with sensory neural hearing loss particularly with NIHL, and that cilia damage contributes to the observed loss of auditory function.
本研究的目的是调查感音神经性听力损失耳朵的耳蜗中的特定结构改变，并确定结构损伤与听觉功能丧失之间的关系。结果表明，使用本研究中所采用的方法能够获得保存良好且具有一致形态特征的结构。因此，对微小病理改变进行检查和识别成为可能。通过扫描电子显微镜发现，内毛细胞（IHC）的静纤毛是兔耳中最易受噪声损伤的结构。内毛细胞损伤的程度与听觉功能丧失的频率范围相当吻合，尤其是中耳肌反射（MER）的阈值偏移。内毛细胞的损伤包括静纤毛融合、断裂以及向外侧毛细胞（OHC）方向倾斜。即使大多数内毛细胞的静纤毛出现明显改变，外侧毛细胞通常仍未改变。在听力严重损失且暴露后时间超过两个月的动物中，在内毛细胞上发现了长的“巨型”纤毛，并且常常还有一根细小的动纤毛。在内毛细胞上也发现了纤毛损伤，其他物种包括人类也存在这种情况，但程度比兔耳中的要小。在噪声暴露前已通过实验切除外侧毛细胞的兔耳中，内毛细胞的静纤毛也受到噪声损伤。得出的结论是，静纤毛损伤是感音神经性听力损失耳朵尤其是噪声性听力损失（NIHL）耳朵中的一种重要形态学改变，并且纤毛损伤导致了观察到的听觉功能丧失。
