听神经瘤的耳声发射观察

目的 观察和分析听神经瘤的耳声发射特点,为评估听神经瘤患者的耳蜗功能和选择保护听力的术式提供参考依据.方法 对20例（22耳）听神经瘤患者行纯音听阈、阻抗、听性脑干反应（auditory brainstem response,ABR）、诱发性耳声发射（evoked otoacoustic emissions,EOAE）测试及CT和（或）MRI扫描,能引出EOAE的瘤耳检测其自发性耳声发射（spontaneous otoacoustic emissions,SOAE）和传出抑制功能.结果 28.57%听神经瘤耳能引出EOAE,按其畸变产物耳声发射（distortion product otoacoustic emissions,DPOAE）特点分为三型：①“耳蜗型”3耳;②“非耳蜗型”2耳;③“混合型”1耳;“非耳蜗型”耳能引出强大的SOAE;能引出EOAE的6耳均有内侧橄榄耳蜗传出系统功能障碍.结论 EOAE可精确分析听神经瘤患者的耳蜗（外毛细胞）功能,部分听神经瘤病人存在“离断耳”现象.耳声发射（otoacousticemissions,OAE）在诊断重度感音神经性聋（包括听神经瘤病人）方面有一定潜能.

An otoacoustic emissions study in patients with acoustic neuroma

OBJECTIVE To investigate and analyze the characteristics of otoacoustic emissions in acoustic neuroma(AN)patients for choosing type of hearing preservation surgery and evaluating the cochlea function of AN patients.METHODS Tests of pure tone audiometry,acoustic impedance audiometry,auditory brainstem response(ABR), evoked otoacoustic emissions(EOAE)and imaging examinations of CT\MRI scan were performed on all 20 patients with verified AN.Spontaneous otoacoustic emissions(SOAE)and efferent suppression test were carried out only in patients with recordable emissions. RESULTS EOAE was detected in 28.57% of the AN ears,These ears were classified into three types based on the characteristics of DPOAE,which were cochlear, noncochlear and mixed type.The noncochlear type showed robust SOAE.All 6 tumor ears with emissions showed the disorders of efferent function. CONCLUSION EOAE can access the function of cochlea(outer hair cells)of AN patients.Phenomenon of dissection ear was found in some AN patients.OAE has potential in diagnosis of the patients with severe or profound deafness(including acoustic neuroma).