Sinha U K, Saadat D, Linthicum F H, Hollen K M, Miller C A
Department of Otolaryngology--Head and Neck Surgery, University of Southern California School of Medicine, USA.
Laryngoscope. 1996 Jan;106(1 Pt 1):1-5. doi: 10.1097/00005537-199601000-00001.
Sensorineural hearing loss has been reported in Alzheimer's disease (AD) and a topographically specific pattern of degeneration in the central auditory system has been described. Although peripheral visual and olfactory systems have been extensively studied, there is no report of peripheral auditory system abnormalities in AD patients. Comparison of temporal bones from eight AD patients with those from eight non-AD controls revealed a significant difference in the percentage of remaining hair cells, peripheral processes, and spiral ganglion cells in the basal cochlear turn but no significant differences in the overall percentage between the two groups. Furthermore, special stains (thioflavin S and Bielschowsky's silver impregnation) of temporal bone nervous tissue from AD patients did not show neuritic plaques and neurofibrillary tangles. It is unclear whether the differences between the two groups in the basal portion of the cochlea are due to AD or some other process, such as presbycusis. However, lack of significant degeneration in other parts of the cochlea and absence of neurofibrillary tangles and neuritic plaques in all eight patients may suggest that the peripheral auditory system, unlike the peripheral visual and olfactory systems, is not involved in AD. A larger sample of AD patients is necessary to clarify the peripheral auditory system findings in the present study.
据报道，阿尔茨海默病（AD）患者存在感音神经性听力损失，且已描述了中枢听觉系统中一种具有特定拓扑结构的退化模式。尽管外周视觉和嗅觉系统已得到广泛研究，但尚无关于AD患者外周听觉系统异常的报道。对8例AD患者的颞骨与8例非AD对照者的颞骨进行比较，结果显示，基底蜗管中剩余毛细胞、外周突和螺旋神经节细胞的百分比存在显著差异，但两组的总体百分比无显著差异。此外，AD患者颞骨神经组织的特殊染色（硫黄素S和 Bielschowsky 银浸染）未显示神经炎性斑块和神经原纤维缠结。尚不清楚两组在蜗管底部的差异是由AD还是其他过程（如老年性耳聋）所致。然而，所有8例患者的耳蜗其他部位均未出现明显退化，且未发现神经原纤维缠结和神经炎性斑块，这可能表明外周听觉系统与外周视觉和嗅觉系统不同，不参与AD病变。需要更大样本量的AD患者来阐明本研究中外周听觉系统的发现。
