Ami Mazita, Abdullah Asma, Awang Mahamad A, Liyab Borhan, Saim Lokman
Department of Otorhinolaryngology-Head and Neck Surgery, Faculty of Medicine. Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
Laryngoscope. 2008 Apr;118(4):712-7. doi: 10.1097/MLG.0b013e318161e521.
To investigate cochlear outer hair cell function based on distortion product otoacoustic emission (DPOAE) in patients with tinnitus.
This is a case control study.
The subjects are patients who attended the Otorhinolaryngology Clinic in Hospital Universiti Kebangsaan Malaysia over a period of 19 months from April 2005 until October 2006. All patients underwent a full ENT assessment and had tympanometry, pure tone audiometry, and DPOAE tests. The UKM Research and Ethics Committee reviewed and approved the study proposal prior to commencement of this study.
The study population included 49 patients. They consisted of 16 patients (32 ears) with tinnitus and reduced hearing, 13 patients (26 ears) with tinnitus and normal hearing, 7 patients (13 ears) without tinnitus with reduced hearing, and 13 patients (26 ears) without tinnitus with normal hearing. Statistical analysis showed significant differences (P = .00) of mean DPOAE levels between the four groups of patients.
Our results suggest that reduced outer hair cell activity, as detected by reduced DPOAE levels, may manifest as tinnitus even before there is a shift on hearing threshold. We also postulate that further reduction of cochlear outer hair cell activity, as shown by further reduced DPOAE levels, may actually terminate the source of tinnitus.
基于畸变产物耳声发射（DPOAE）研究耳鸣患者的耳蜗外毛细胞功能。
这是一项病例对照研究。
研究对象为2005年4月至2006年10月期间在马来西亚国立大学医院耳鼻喉科门诊就诊的患者。所有患者均接受了全面的耳鼻喉科评估，并进行了鼓室导抗图、纯音听力测定和DPOAE测试。在本研究开始前，马来西亚国立大学研究与伦理委员会对研究方案进行了审查并批准。
研究人群包括49例患者。其中有耳鸣且听力下降的患者16例（32耳），有耳鸣且听力正常的患者13例（26耳），无耳鸣但听力下降的患者7例（13耳），无耳鸣且听力正常的患者13例（26耳）。统计学分析显示，四组患者的平均DPOAE水平存在显著差异（P = 0.00）。
我们的研究结果表明，DPOAE水平降低所检测到的外毛细胞活性降低，可能在听力阈值改变之前就表现为耳鸣。我们还推测，DPOAE水平进一步降低所显示的耳蜗外毛细胞活性进一步降低，可能实际上会终止耳鸣的源头。
