Chéry-Croze S, Moulin A, Collet L, Morgon A
URA CNRS 1447, Hôpital E. Herriot, Lyon, France.
Br J Audiol. 1994 Feb;28(1):13-25. doi: 10.3109/03005369409077909.
The present results are drawn from preliminary observations made in 28 patients suffering from unilateral, permanent, non-pulsatile tinnitus, who were systematically submitted to an investigation of their otoacoustic emissions in both ears. Spontaneous otoemissions (SOAE) were carefully looked for, before recording of transient evoked otoemissions (TEOAE). The effectiveness of the medial olivo-cochlear efferent system (MOC) was also tested. The comparison between TEOAE input/output curves obtained with and without contralateral stimulation allowed a global assessment of the functioning of MOC. Additional information relating to the MOC functioning at the precise frequency of tinnitus and/or around it, was available from the comparison of analogous curves obtained using distortion product otoacoustic emissions (DPOAE) instead of TEOAEs. The results show that: (1) when the amplitude of otoacoustic emissions differs between the two ears, the tinnitus is generally lateralized on the side where amplitude was the lowest, which seems to be related to a greater hearing loss; (2) no general law concerning tinnitus can be drawn from the global testing of MOC functioning; the only result is that the slope of TEOAE input/output function appears as a deciding factor for efficiency of MOC, the least efficiency almost always occurring on the side where the slope is greater, and (3) even in the case of proved global effectiveness of MOC activation, there is, at least in the vicinity and in at least one ear, a part of the cochlea where its functioning is altered. A better comprehension of the mechanisms underlying this symptom will probably come from exhaustive exploration of individual cases rather than a rougher investigation of large samples in which different aetiologies are likely to be mixed.
目前的研究结果来自于对28例单侧、永久性、非搏动性耳鸣患者的初步观察，这些患者均接受了双耳耳声发射的系统检查。在记录瞬态诱发耳声发射（TEOAE）之前，仔细寻找自发性耳声发射（SOAE）。还测试了内侧橄榄耳蜗传出系统（MOC）的有效性。通过比较在有和没有对侧刺激情况下获得的TEOAE输入/输出曲线，可以对MOC的功能进行整体评估。通过比较使用畸变产物耳声发射（DPOAE）而非TEOAE获得的类似曲线，可以获得与耳鸣精确频率和/或其周围MOC功能相关的更多信息。结果表明：（1）当双耳耳声发射的幅度不同时，耳鸣通常偏向幅度最低的一侧，这似乎与更大的听力损失有关；（2）从MOC功能的整体测试中无法得出关于耳鸣的一般规律；唯一的结果是，TEOAE输入/输出函数的斜率似乎是MOC效率的决定性因素，效率最低的情况几乎总是出现在斜率较大的一侧，并且（3）即使在证明MOC激活具有整体有效性的情况下，至少在附近以及至少一只耳朵中，耳蜗的一部分其功能发生了改变。对该症状潜在机制的更好理解可能来自对个体病例的详尽探索，而非对可能混合了不同病因的大样本进行更粗略的研究。
