中枢性低频听力减退的听力学分析

目的 加深对双侧中枢性低频听力减退的认识。方法 复习１９８８～２０００年１０１例原因不明的双侧感音神经性低频听力减退患者的听力学检查结果。结果 其共同的特点是：言语听力不成比例地差于纯音听力，诱发性耳声发射正常，不受对侧噪声抑制，引不出镫骨肌声反射，听性脑干反应（ａｕｄｉｔｏｒｙ ｂｒａｉｎｓｔｅｍ ｒｅｓｐｏｎｓｅ，ＡＢＲ）异常，－ＳＰ／ＡＰ振幅比大于０．４４。结论 此类原因不明的低频听力减退患者听力学表现提示：耳蜗外毛细胞功能正常，与声反射、听传出抑制、ＡＢＲ波Ⅲ相关的脑干听觉神经径路为功能障碍的主要部位，可伴有耳蜗或传入神经功能障碍。建议使用“中枢性低频听减退”的名称。

Central low frequency hearing loss]

OBJECTIVE: To study the pathogenesis of the bilateral central low frequency hearing loss. METHODS: Audiologic findings auditory brainstem response(ABR), evoked otoacoustic emission (EOAE), et al] of 101 cases with bilateral central low frequency hearing loss were studied. RESULTS: The typical clinical manifestations of bilateral central low frequency hearing loss were normal EOAE which cannot be suppressed by contralateral white noise, abnormal ABR, no acoustic reflex and--SP/AP > 0.44. CONCLUSIONS: The results suggest that cochlear outer hair cells are normal in function with dysfunction of the cochlear nuclei. The main lesion of the disease are neural pathways related to Acoustic reflex and medial olivo-cochlear efferent nervous system. The cochlear afferent nerve may also be involved.