Objective: To reclassify the flat type sudden deafness according to the types of audiogram shape, and to explore the correlation between different pattern of hearing loss and prognosis. Methods: All of 1 024 patients with unilateral sudden deafness (492 males and 532 females, aged from 19 to 65 years, with an average age of 41.2 years old) admitted to 33 hospitals nationwide from August 2007 to October 2011 were divided into four types according to Chinese Guideline of Sudden Deafness(2015): low-frequency, high-frequency, flat and total deafness. Then, 402 patients with flat type sudden deafness were further divided into ascending type, descending type and consistent type according to the audiogram shapes. First, we compared the clinical characteristics and prognosis among these three subtypes of flat deafness, then compared the clinical characteristics and prognosis between ascending flat deafness and low-frequency deafness, descending flat deafness and high-frequency deafness, consistent flat deafness and total deafness, explored the factors related to the prognosis of flat deafness. SPSS 21.0 software, ANOVA, χ2 test, t-test and Logistic regression were used to analyze the data. Results: The cure rates of flat ascending, flat descending and flat consistent sudden deafness groups were 70.7%, 17.1% and 34.0% respectively, with a statistically significant difference (χ2=33.984, P<0.001); However, there was no significant difference in age, sex and affected side (all P>0.05). The independent related factors for the recovery of flat type sudden deafness were as follows: whether there was dizziness [OR=0.459; 95% confidence interval (CI): 0.271-0.777], the type of audiogram shape (OR=0.721; 95%CI: 0.530-0.981), and days from onset to therapy (OR=0.903, 95%CI: 0.835-0.978), all of which had P values<0.05. There was no significant difference in the cure rates between ascending flat sudden deafness and low-frequency descending sudden deafness, descending flat sudden deafness and high-frequency descending sudden deafness (all P>0.05). The pure tone average(PTA) of flat consistent sudden deafness and total deafness were (69.1±18.9) and (101.7±17.7) dB HL, respectively, with a statistically significant difference (t=20.890, P<0.001), and the cure rates were 34.0% and 14.5%, respectively, with a statistically significant difference (χ2=29.012, P<0.001). Conclusion: According to the audiogram shape, the flat type sudden deafness can be further divided into ascending flat sudden deafness, descending flat sudden deafness and consistent flat sudden deafness, which can more effectively evaluate the prognosis. The cure rate of ascending flat sudden deafness is similar to that of low-frequency sudden deafness, and the prognosis is well; The cure rate of descending flat sudden deafness is similar to that of high-frequency descending sudden deafness, and the prognosis is poor. The cure rate of consistent flat sudden deafness is higher than that of total deafness. PTA plays an important role in the prognosis of consistent flat sudden deafness and total deafness. Total deafness can be regarded as a single type of sudden deafness.
目的： 探讨可否依据听力曲线类型对突发性聋（突聋）中的平坦型突聋进一步分型，明确不同听力曲线类型与突聋预后的相关性。 方法： 本研究为回顾性队列研究。依据2015年突聋诊断和治疗指南将2007年8月至2011年10月全国33家医院收治的1 024例（其中男492例，女532例；年龄19~65岁，平均年龄41.2岁）单侧突聋患者分为低频、高频、平坦及全聋型突聋4型；将其中402例平坦型突聋患者依据听力曲线类型进一步分为：平坦上升型、平坦下降型、平坦一致型3组。比较3组间的临床特点及预后，比较平坦上升型与低频下降型突聋、平坦下降型与高频下降型突聋、平坦一致型与全聋型突聋的临床特点及预后，探讨影响平坦型突聋预后的相关因素。采用SPSS 21.0软件对数据进行分析，应用方差分析、χ2检验、t检验及Logistic回归对数据进行分析。 结果： 平坦上升、平坦下降、平坦一致型突聋3组的痊愈率分别为70.7%、17.1%、34.0%，差异有统计学意义（χ2=33.984，P<0.001）；而年龄、性别、发病侧别差异无统计学意义（P值均>0.05）。平坦型突聋痊愈的影响因素为：是否伴有头晕［OR=0.459，95%可信区间（CI）：0.271~0.777］、听力曲线类型（OR=0.721，95%CI：0.530~0.981）和发病至就诊天数（OR=0.903，95%CI：0.835~0.978），P值均<0.05。平坦上升型与低频下降型突聋、平坦下降型与高频下降型突聋的痊愈率差异均无统计学意义（P值均>0.05）。平坦一致型与全聋型突聋的平均纯音听阈（pure tone average，PTA）为（69.1±18.9）dB HL和（101.7±17.7）dB HL，差异有统计学意义（t=20.890，P<0.001），痊愈率分别为34.0%和14.5%，差异有统计学意义（χ2=29.012，P<0.001）。 结论： 可对平坦型突聋进一步分为平坦上升型、平坦下降型、平坦一致型。其中平坦上升型痊愈率与低频下降型突聋相似，预后较好；平坦下降型痊愈率与高频下降型突聋相似，预后较差；平坦一致型痊愈率高于全聋型突聋，PTA在平坦一致型和全聋型突聋的预后中起重要作用。.