Department of Otorhinolaryngology-Head and Neck Surgery, Konkuk University School of Medicine, Seoul, Korea.
Otol Neurotol. 2010 Aug;31(6):862-6. doi: 10.1097/MAO.0b013e3181e8fb47.
The function of outer hair cells can be measured objectively and noninvasively by distortion product otoacoustic emission (DPOAE). The aims of the study were to investigate the changes of DPOAE in the recovery course and to pursue the relationship between the changes of DPOAE and hearing improvement in patients with sudden sensorineural hearing loss.
: Retrospective case series review.
Both DPOAE and pure tone audiometry were performed before 7 days after the onset and followed after 2 weeks in 40 patients with sudden sensorineural hearing loss. Patients were grouped on the basis of the initial hearing loss and the results of their recovery. All DPOAE amplitudes were analyzed at 2f1-f2, and DPOAE sum was calculated.
The initial DPOAE sum in ears with the initial mild-to-moderate hearing loss (hearing threshold, <or=55 dB) was not different from that in contralateral normal ears, but it was decreased or absent in ears with the initial moderately severe to profound hearing loss (hearing threshold, >55 dB) compared with that in contralateral normal ears. In ears with the initial moderately severe to profound hearing loss, the changes of DPOAE sum values positively correlated with the hearing improvement but not in ears with the initial mild-to-moderate hearing loss. Although the presence of initial DPOAE responses indicated good prognosis, the absence of initial DPOAE responses did not always indicate poor prognosis.
Our findings showed that the function of outer hair cells is relatively spared in ears with the initial mild-to-moderate hearing loss, and its recovery is not related to the hearing improvement; however, the function of outer hair cells is impaired in ears with the initial moderately severe to profound hearing loss, and the functional improvement of outer hair cells is important for hearing recovery. Clinical implications of our findings were discussed.
通过畸变产物耳声发射（DPOAE）可客观、无创地测量外毛细胞的功能。本研究旨在探讨 DPOAE 在恢复过程中的变化，并探讨其与突发性聋患者听力改善的关系。
回顾性病例系列研究。
40 例突发性聋患者在发病后 7 天内进行 DPOAE 和纯音测听检查，随后在 2 周内进行随访。根据初始听力损失和恢复结果对患者进行分组。在 2f1-f2 处分析所有 DPOAE 幅度，并计算 DPOAE 总和。
初始轻度至中度听力损失（听力阈值，≤55 dB）耳的初始 DPOAE 总和与对侧正常耳无差异，但初始中重度至重度听力损失（听力阈值，>55 dB）耳的 DPOAE 总和与对侧正常耳相比有所降低或缺失。在初始中重度至重度听力损失的耳中，DPOAE 总和值的变化与听力改善呈正相关，但在初始轻度至中度听力损失的耳中则无相关性。虽然初始 DPOAE 反应的存在提示预后良好，但初始 DPOAE 反应的缺失并不总是预示预后不良。
我们的发现表明，在初始轻度至中度听力损失的耳中，外毛细胞的功能相对保留，其恢复与听力改善无关；然而，在初始中重度至重度听力损失的耳中，外毛细胞的功能受损，外毛细胞的功能改善对外界声音是听力恢复的重要因素。我们对这一发现的临床意义进行了讨论。
