Braun Susanne, Ye Qing, Radeloff Andreas, Kiefer Jan, Gstoettner Wolfgang, Tillein Jochen
Department of Sensory Physiology II, J.W. Goethe University, Frankfurt am Main, Germany.
ORL J Otorhinolaryngol Relat Spec. 2011;73(4):219-28. doi: 10.1159/000329791. Epub 2011 Jul 21.
Cochlear implant users with residual hearing often benefit greatly from simultaneous electric and acoustic stimulation. However, implantation can cause trauma to the inner ear, resulting in poorer hearing postoperatively. We investigated whether a single local injection of glucocorticoids can reduce hearing loss in long-term implanted guinea pigs.
Three groups of animals underwent bilateral surgery. One ear was implanted with an electrode, and the contralateral ear received a cochleostomy only. A single dose of the glucocorticoids triamcinolone or dexamethasone, or of artificial perilymph was infused into cochleae via cochleostomy. Compound action potentials were measured before and after application and for 3 months postoperatively. Tissue growth was measured as the percentage of the total area of the scala tympani that was obliterated.
Ears subjected to cochleostomy only and treated with glucocorticoids demonstrated a mild hearing loss. In the implanted ears, both glucocorticoids preserved hearing at least temporarily. The volume of tissue growth within the scala tympani was not reduced, and there was no relation between the amount of tissue and hearing loss.
Both glucocorticoids show a potential benefit for hearing preservation in implanted ears. Glucocorticoid therapy may be useful to protect residual hearing during cochlear implantation.
有残余听力的人工耳蜗使用者通常能从电刺激和声刺激同时进行中获益良多。然而，植入手术可能会对内耳造成创伤，导致术后听力变差。我们研究了单次局部注射糖皮质激素是否能减少长期植入人工耳蜗的豚鼠的听力损失。
三组动物接受双侧手术。一只耳朵植入电极，对侧耳朵仅进行蜗窗造口术。通过蜗窗造口术将单剂量的糖皮质激素曲安奈德或地塞米松，或人工外淋巴液注入耳蜗。在给药前、给药后以及术后3个月测量复合动作电位。通过测量鼓阶被阻塞的总面积占比来衡量组织生长情况。
仅接受蜗窗造口术并接受糖皮质激素治疗的耳朵出现了轻度听力损失。在植入人工耳蜗的耳朵中，两种糖皮质激素至少暂时保留了听力。鼓阶内组织生长的体积并未减少，并且组织量与听力损失之间没有关联。
两种糖皮质激素都显示出对植入人工耳蜗的耳朵保存听力有潜在益处。糖皮质激素疗法可能有助于在人工耳蜗植入期间保护残余听力。
