Patterns of neural degeneration in the human cochlea and auditory nerve: Implications for cochlear implantation
Patterns of neural degeneration in the human cochlea and auditory nerve: Implications for cochlear implantation
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DOI：
10.1016/s0194-5998(97)70178-5
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发表时间：
1997-09-01
影响因子：
3.4
通讯作者：
Nadol, JB
中科院分区：
文献类型：
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作者：
Nadol, JB
虽然所有可能影响人工耳蜗植入术后语音识别的变量都是未知的，但螺旋神经节细胞的保存程度通常被认为是最重要的。本文总结了我们实验室针对深度耳聋患者存活螺旋神经节细胞的定量、各种临床参数的预测价值评估以及内耳植入后果评估的一系列实验。生前耳聋患者的内耳组织学研究表明，耳聋的原因占螺旋神经节细胞计数变异性的57%。螺旋神经节细胞计数在氨基糖苷中毒或突发性特发性耳聋的个体中最高；耳聋和最低的聋由出生后病毒性迷路炎，先天性或遗传性耳聋，或细菌性脑膜炎。对螺旋神经节变性的决定因素的研究表明，与根尖匝相比，基底匝的变性最为严重，当内外毛细胞均缺失时，变性更为严重。与一些实验动物研究的结果不同，II型神经节细胞没有生存优势，耳蜗骨闭塞程度与螺旋神经节细胞计数正常之间存在较强的负相关。然而，即使在严重骨闭塞的标本中，仍有大量的螺旋神经节细胞存活。耳蜗、前庭神经和第八脑神经直径与胎儿螺旋神经节细胞计数呈正相关（p < 0.001）。这将提示现代成像技术可用于预测残余螺旋神经节细胞群在人工耳蜗候选人。在人体颞骨模型和生前接受电极阵列植入的个体颞骨中研究了电极阵列植入的创伤。耳蜗外侧壁和基底膜损伤的典型模式是在上基底转。人工耳蜗植入术后常见新骨形成和电极周围纤维化。尽管有这种严重的创伤和反应，但没有确凿的证据表明螺旋神经节的进一步退化可以预测其后果。
Although the identity of all the variables that may influence speech recognition after cochlear implantation is unknown, the degree of preservation of spiral ganglion cells is generally considered to be of primary importance. A series of experiments in our laboratories, directed at quantification of surviving spiral ganglion cells in the profoundly deaf, evaluation of the predictive value of a variety of clinical parameters, and the evaluation of the consequences of implantation in the inner ear, is summarized. Histologic study of the inner ears of patients who were deafened during life demonstrated that the cause of deafness accounted for 57% of the variability of spiral ganglion cell counts. Spiral ganglion cell counts were highest in individuals deafened by aminoglycoside toxicity or sudden idiopathic; deafness and lowest in those deafened by postnatal viral labyrinthitis, congenital or genetic deafness, or bacterial meningitis. Study of the determinants of degeneration of the spiral ganglion revealed that degeneration is most severe in the basal compared with the apical turn and more severe when both inner and outer hair cells are absent. Unlike the findings in some experimental animal studies, no survival advantage of type II ganglion cells could be identified there was a strong negative correlation between the degree of bony occlusion of the cochlea and the normality of the spiral ganglion cell count. However, even in specimens in which there was severe bony occlusion, significant numbers of spiral ganglion cells survived. A strong positive correlation between the diameter of the cochlear, vestibular, and eighth cranial nerves with the fetal spiral ganglion cell count (p < 0.001) was found. This would suggest that modern imaging techniques may be used to predict residual spiral ganglion cell population in cochlear implant candidates. Trauma from implantation of the electrode array was studied in both cadaveric human temporal bone models and temporal bones from individuals who received implants during life. A characteristic pattern of damage to the lateral cochlear wall and basilar membrane was identified in the upper basal turn. New bone formation and perielectrode fibrosis was common after cochlear implantation. Despite this significant trauma and reaction, there is no firm evidence that further degeneration of the spiral ganglion can be predicted as a consequence.