Tabuchi Keiji, Murashita Hidekazu, Okubo Hideki, Takahashi Kazuhiko, Wada Tetsuro, Hara Akira
Department of Otolaryngology, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Japan.
Arch Otolaryngol Head Neck Surg. 2005 Aug;131(8):686-9. doi: 10.1001/archotol.131.8.686.
To evaluate the usefulness of pure-tone audiometry, tympanometry, and liquid and acoustic reflex (AR) tests in the differential diagnosis of ossicular fixation and discontinuity.
A prospective clinical trial.
Tertiary referral center.
Thirty-nine patients (46 ears) undergoing operations at University of Tsukuba Hospital, Tsukuba, Japan, from 1990 through 2003 for conductive deafness without perforation of the tympanic membrane. Clinical examinations for the preoperative diagnosis included pure-tone audiometry, tympanometry, and liquid and AR tests. We compared the preoperative diagnosis with the surgical findings.
Although neither pure-tone audiometry nor tympanometry contributed to the differential diagnosis of ossicular chain abnormality, liquid and AR test results showed a significant difference between fixation and discontinuity of the ossicular chain. With the liquid test, bone conduction at lower frequencies was improved by filling the external auditory canal with water at lower frequencies in cases of ossicular fixation. In contrast to the findings observed in ossicular fixation, no improvement of the threshold of bone conduction was recognized at any frequency in the ears with ossicular discontinuity. In ipsilaterally stimulated AR, the reversed pattern was the most marked at 2000 and 500 Hz in ossicular fixation and discontinuity, respectively.
Liquid and AR tests are reliable examinations for the differential diagnosis of ossicular fixation and discontinuity.
评估纯音听力测定、鼓室导抗图以及镫骨肌声反射（AR）测试在鉴别听骨链固定与中断方面的作用。
一项前瞻性临床试验。
三级转诊中心。
1990年至2003年期间，在日本筑波大学筑波医院接受手术的39例患者（46耳），均为鼓膜无穿孔的传导性聋。术前诊断的临床检查包括纯音听力测定、鼓室导抗图以及镫骨肌声反射测试。我们将术前诊断结果与手术发现进行了比较。
尽管纯音听力测定和鼓室导抗图对听骨链异常的鉴别诊断均无帮助，但镫骨肌声反射测试结果显示，听骨链固定与中断之间存在显著差异。在镫骨肌声反射测试中，对于听骨链固定的病例，通过在低频时向外耳道注水，低频骨导得到改善。与听骨链固定的情况相反，听骨链中断的耳在任何频率下骨导阈值均未改善。在同侧刺激的镫骨肌声反射中，听骨链固定和中断时，反转模式分别在2000Hz和500Hz时最为明显。
镫骨肌声反射测试是鉴别听骨链固定与中断的可靠检查方法。
