庆大霉素慢性耳中毒对听觉和传出神经功能的影响

The effect of chronic ototoxicity of gentamicin on the function of auditory efferents

目的 :探讨庆大霉素慢性耳中毒对听觉和传出神经功能的影响。方法 :在庆大霉素应用前后通过观察对侧噪声 (CL N)对听神经复合动作电位 (CAP)的影响确定内侧橄榄耳蜗 (MOC)系统功能 ,通过测试在 4,6 ,8,10和 12 k Hz的 CAP反应阈确定听功能。结果 :注射庆大霉素后 3周和 11周 ,CL N对 CAP的抑制效应呈进行性、不可逆性消除 ,且以 11周最明显 (P <0 .0 1) ,CAP反应阈分别上升 10和 2 5 d B,与耳蜗传出神经和毛细胞的形态学改变一致。结论

Objective:To study the effect of chronic ototoxicity of gentamicin on the function of the cochlea and auditory efferents.Method:The effect of chronic ototoxicity of gentamicin on the function of the cochlea was determined by recording thresholds of the compound action potentials (CAP) of the auditory nerves to tone pip at 4,6,8,10 and 12 kHz.The function of the medial olivocochlear (MOC) system was determined,through the observation of the effect of the contralateral niose (CLN) on CAP,before and after gentamicin administration.Result:The suppression effects of CLN on CAP were irreversibly eliminated,and the effects were most obvious at the 11th week after gentamicin (P< 0.01 ),and the response threshold of CAP was raised about 10 dB and 25 dB,respectively,at the 3rd and 11th week after the application of gentamicin.These results were most related to the morphological changes on cochlear efferents and hair cells.Conclusion:The auditory efferents play an important role in the chronic ototoxicity of gentamicin.