Scholtz A W, Kammen-Jolly K, Felder E, Hussl B, Rask-Andersen H, Schrott-Fischer A
Department of Otolarynology, University of Innsbruck, Austria.
Hear Res. 2001 Jul;157(1-2):77-86. doi: 10.1016/s0378-5955(01)00279-9.
Accompanied with aging, the thresholds for high frequency sounds may elevate and result in a progressive hearing loss described as presbycusis. Based on correlations between audiometric measures of aged patients and histologic findings garnered from postmortem examinations, four types of presbycusis have been characterized: sensory-neural, neural, strial, and conductive [Schuknecht, H.F., Gacek, M.R., 1993. Ann. Otol. Rhinol. Laryngol. 102, 1--16]. Otopathologic changes to the inner ear as a direct function of age, however, remain controversial. The focus of this investigation involves the pathological impact on remaining sensory structures in patients having sensory--neural degeneration. The current study presents seven human temporal bones extracted from patients aged 53--67 years with high-tone hearing loss and with no known history of extraordinary environmental events involving head or noise trauma, acoustic overstimulation, or ototoxicity. In previously published findings of these specimens, all but one temporal bone failed to demonstrate a meaningful correlation between audiometric measurements and loss of functional hair cell populations with secondary retrograde degeneration of nerve fibers. Using the block surface method, electron microscopic micrographs demonstrate ultrastructural changes in the cuticular plate, stereocilia, pillar cells, stria vascularis, and the spiral ligament. In all pathological specimens, the greatest incidence of degeneration was seen at the cuticular plate. Conclusively, our findings present three implications in the aging human cochlea: firstly, audiometric measures that represent a high-tone hearing loss may take various forms with respect to ultrastructural patterns of degeneration and surviving structures; secondly, the incidence of lipofuscin and lysosome granules does not correlate with the degree of hearing loss and; thirdly, as shown only in guinea pigs [Anniko, M., 1988. Scanning Microsc. 2, 1035--1041], high-tone hearing loss can be associated with deformation of the cuticular plate.
随着年龄的增长，高频声音的阈值可能会升高，导致一种称为老年性聋的进行性听力损失。根据老年患者听力测定指标与尸检组织学结果之间的相关性，老年性聋已被分为四种类型：感觉神经性、神经性、血管纹性和传导性[舒克内希特，H.F.，加塞克，M.R.，1993年。《耳鼻咽喉头颈外科杂志》102卷，第1 - 16页]。然而，内耳作为年龄直接作用的病理变化仍存在争议。本研究的重点是感觉神经性退变患者中剩余感觉结构的病理影响。本研究展示了从53 - 67岁患有高音听力损失且无涉及头部或噪声创伤、声学过度刺激或耳毒性等特殊环境事件已知病史的患者中提取的七块人类颞骨。在这些标本先前发表的研究结果中，除一块颞骨外，所有颞骨在听力测定结果与功能性毛细胞群体丧失及神经纤维继发性逆行性退变之间均未显示出有意义的相关性。使用块面法，电子显微镜显微照片显示了表皮板、静纤毛、柱细胞、血管纹和螺旋韧带的超微结构变化。在所有病理标本中，表皮板处的退变发生率最高。总之，我们的研究结果对衰老的人类耳蜗有三点启示：首先，代表高音听力损失的听力测定结果在退变的超微结构模式和存活结构方面可能有多种形式；其次，脂褐素和溶酶体颗粒的发生率与听力损失程度无关；第三，如仅在豚鼠中所示[安妮科，M.，1988年。《扫描显微镜》2卷，第1035 - 1041页]，高音听力损失可能与表皮板变形有关。
