Sztuka Aleksandra, Pośpiech Lucyna, Gawron Wojciech, Dudek Krzysztof
Katedra i Klinika Otolaryngologii AM we Wrocławiu.
Otolaryngol Pol. 2006;60(5):765-72.
The most probable place generating tinnitus in auditory pathway are outer hair cells (OHC) inside cochlea. To asses their activity otoacoustic emission is used. The goal of the investigation was estimation the features of otoemission DPOAE in groups with tinnitus patients with cochlear hearing loss, estimation of diagnostic value of DPOAE parameters for analysis of function of the cochlea in investigated patients emphasizing DPOAE parameters most useful in localizing tinnitus generators and estimation of hypothetic influence of hyperacusis and misophony on parameters of DPOAE in tinnitus patients with cochlear hearing loss. The material of the study were 42 tinnitus patients with cochlear hearing loss. In the control group there were 21 patients without tinnitus with the same type of hearing loss. Then tinnitus patients were divided into three subgroups--with hyperacusis, misophony and without both of them, based on audiologic findings.
after taking view on tinnitus and physical examination in all the patients pure tone and impedance audiometry, supratreshold tests, ABR and audiometric average and discomfort level were evaluated. Then otoemission DPOAE was measured in three procedures. First the amplitudes of two points per octave were assessed, in second--"fine structure" method-- 16-20 points per octave (f2/f1 = 1.2, L1 = L2 = 70 dB). Third procedure included recording of growth rate function in three series for input tones of value f2 = 2002, 4004, 6006 Hz (f2/f1= 1.22) and levels L1=L2, growing by degrees of 5dB in each series.
DPOAE amplitudes in recording of 2 points per octave and fine structure method are very valuable parameters for estimation of cochlear function in tinnitus patients with cochlear hearing loss. Decreasing of DPOAE amplitudes in patients with cochlear hearing loss and tinnitus suggests significant role of OHC pathology, unbalanced by IHC injury in generation of tinnitus in patients with hearing loss of cochlear localization. DPOAE fine structure provides us the additional information about DPOAE amplitude recorded in two points per octave, spreading the amount of frequencies f2, where differences are noticed in comparison of two groups--tinnitus patients and control. Function growth rate cannot be the only parameter in estimation of DPOAE in tinnitus patients with cochlear hearing loss, also including subjects with hyperacusis and misophony. Hyperacusis has important influence on DPOAE amplitude, increases essentially amplitude of DPOAE in the examined group of tinnitus patients.
听觉通路中最有可能产生耳鸣的部位是耳蜗内的外毛细胞（OHC）。为评估其活性，采用了耳声发射。本研究的目的是评估耳蜗性听力损失耳鸣患者组中畸变产物耳声发射（DPOAE）的特征，评估DPOAE参数对所研究患者耳蜗功能分析的诊断价值，强调对耳鸣产生部位定位最有用的DPOAE参数，并评估听觉过敏和恐音症对耳蜗性听力损失耳鸣患者DPOAE参数的假设影响。研究材料为42例耳蜗性听力损失耳鸣患者。对照组为21例无耳鸣且听力损失类型相同的患者。然后根据听力学检查结果，将耳鸣患者分为三个亚组——有听觉过敏、有恐音症和两者都没有的。
对所有患者进行耳鸣问诊和体格检查后，评估纯音和阻抗测听、阈上测试、听性脑干反应（ABR）以及听阈均值和不适阈。然后分三步测量耳声发射DPOAE。第一步，评估每倍频程两个点的幅值；第二步，采用“精细结构”法，每倍频程16 - 20个点（f2/f1 = 1.2，L1 = L2 = 70 dB）。第三步，对f2 = 2002、4004、6006 Hz（f2/f1 = 1.22）的输入音，分三个系列记录其增长率函数，每个系列中L1 = L2，以5 dB的幅度递增。
每倍频程两个点记录的DPOAE幅值以及精细结构法是评估耳蜗性听力损失耳鸣患者耳蜗功能的非常有价值的参数。耳蜗性听力损失耳鸣患者中DPOAE幅值降低表明，在耳蜗定位性听力损失患者耳鸣产生过程中，OHC病变起重要作用，而内毛细胞（IHC）损伤未起平衡作用。DPOAE精细结构为我们提供了关于每倍频程两个点记录的DPOAE幅值的额外信息，扩展了f2频率范围，在耳鸣患者组和对照组的比较中可观察到差异。增长率函数不能作为评估耳蜗性听力损失耳鸣患者（包括有听觉过敏和恐音症的患者）DPOAE的唯一参数。听觉过敏对DPOAE幅值有重要影响，在被检查的耳鸣患者组中显著增加了DPOAE的幅值。
