听觉传导通路不同部位的病变对中枢掩蔽的影响  

Pathology in Different Sites of Auditory Pathway had Different Effects on the Central Masking

作　　者：曾祥丽[1] 龚树生[1] 钟乃川[1] 

机构地区：[1]华中科技大学同济医学院附属协和医院耳鼻咽喉科,武汉430022

出　　处：《听力学及言语疾病杂志》2005年第2期79-82,共4页Journal of Audiology and Speech Pathology

摘　　要：目的　了解听觉传导通路不同部位的病变对中枢掩蔽的影响 ,为临床分析掩蔽测试结果提供参考。方法　分别对一侧耳正常另一侧耳为传导性聋的患者 30例 (外伤性鼓膜穿孔、分泌性中耳炎及慢性化脓性中耳炎各 10例 )、耳蜗性聋患者 2 7例 (突聋伴眩晕 7例、突聋不伴眩晕及原因不明各 10例 )、蜗后性聋患者 7例 (单侧听神经瘤 3例 ,单侧听神经病 4例 )进行中枢掩蔽测试。结果　外伤性鼓膜穿孔 10耳中枢掩蔽接近正常 ;分泌性中耳炎及慢性化脓性中耳炎中枢掩蔽有不同程度的降低。突聋合并眩晕耳 ,中枢掩蔽效应高于正常耳 10dB以上 ,且有极大的个体差异 ;而在其他耳蜗病变耳 ,中枢掩蔽幅值明显低于正常耳。蜗后病变耳中枢掩蔽表现也各异。结论　在中耳病变耳 ,当对侧掩蔽声达 4 0dBEM时 ,中枢掩蔽效应大于 5dB ,故如掩蔽测试时所用掩蔽声大于 4 0dBEM则需对测试结果进行修正。在突聋伴眩晕耳 ,因中枢掩蔽效应幅值极大 ,故测试气导听阈时 ,应尽可能用插入式耳机 ,骨导测试应放弃。在蜗后病变耳应根据具体情况拟定掩蔽方案。Objective To investigate the appropri ate changes of the central masking effect(CME) when there were pathologies in d ifferent segment of auditory pathway,so as to give some instructions in cli nical masking test. Methods We tested the subjects with one ear normal and th e other ear diseased. The diseased ears included conductive deafness in 30 ca ses?sensory deafness in 27 cases and retrocochlear deafness in 7 cases. Results The pure conductive deafness had very little effect on CME; secretory otistis media and chronic suppurative otistis medi a made CME lower than normal due to the secondary cochlear impairment .When su dden deafness companied with vertigo,CME appeared much higher than the normal and appeared great difference individually;but CME appeared lower than normal at other kinds of cochlear deafness ears.CME appeared differently at retrocochlear deafness ears. Conclusion Audiometry results should be corrected when th e masker higher than 40 dB EM,because the masker can make the CME higher than 5 dB in the conductive impairment ears.In the sudden de afness companied with vertigo ears,CMEs were too high and too individually to fi nd a suitable correction for PTT.Insert earphone should be used in measuring the air-conduction PTT,and bone-conduction PTT test might be given up.

关 键 词：听觉通路 病变 中枢掩蔽 

分 类 号：R764.4[医药卫生—耳鼻咽喉科]