Baisakhiya Nitish, Singh Gurchand
Department of ENT, MMIMSR, Mullana, Ambala, India.
Indian J Otolaryngol Head Neck Surg. 2019 Nov;71(Suppl 2):1357-1363. doi: 10.1007/s12070-018-1424-2. Epub 2018 Jun 18.
Tubo-tympanic disease of middle ear cleft can temporarily detoriate the bone conduction threshold specially in higher frequency in long standing cases. It mainly affects the inertial ossicular component of the bone conduction mechanism. (1) Study the effect of tubotympanic disease on bone conduction threshold (SN loss). (2) Study the duration of the disease on bone conduction threshold. 84 cases of tubotympanic disease were taken for the study. There pre-operative PTA was done and effect of the disease on the bone conduction threshold was noted. Results were analyzed by using analysis of variance. The significance level α was taken 0.05 as at marginally significant, 0.01 significant and 0.001 as highly significant. The bone conduction at all frequencies increased significantly < 0.05 with duration of ear discharge. The differences in the bone conduction at all frequencies amongst normal ears were significantly lower as compared to the diseased ear. Duration of ear discharge and type of hearing loss reveals that in patients with ear discharge less than 11 years there were 24 (77.41%) subjects with conductive hearing loss, 1 (3.22%) subject with mixed hearing loss. As the duration increased 11-20 years, the cases of conductive hearing loss decreased 13 (56.52%) and cases of mixed hearing loss increased to 3 (13.04%). In patients with ear discharge of > 21 years conductive subjects were 19 (63.33%) and subjects with mixed hearing loss increased to 5 (33.33%) cases. The average hearing loss and the average bone conduction threshold increases as the duration of disease increases. In patients of safe CSOM who have poor BCT, it is the higher frequencies which are more affected.
中耳裂的鼓室-鼓膜疾病在病程较长的情况下，可使骨导阈值暂时恶化，尤其是在高频段。它主要影响骨导机制的惯性听骨成分。（1）研究鼓室-鼓膜疾病对骨导阈值（感音神经性听力损失）的影响。（2）研究疾病持续时间对骨导阈值的影响。选取84例鼓室-鼓膜疾病患者进行研究。术前进行纯音听阈测试，并记录疾病对骨导阈值的影响。采用方差分析对结果进行分析。显著性水平α取0.05为边缘显著，0.01为显著，0.001为高度显著。随着耳漏持续时间的增加，所有频率的骨导均显著增加（<0.05）。与患病耳相比，正常耳在所有频率的骨导差异显著更低。耳漏持续时间和听力损失类型显示，耳漏少于11年的患者中，有24例（77.41%）为传导性听力损失，1例（3.22%）为混合性听力损失。随着病程增加到11 - 20年，传导性听力损失病例减少至13例（56.52%），混合性听力损失病例增加至3例（13.04%）。耳漏超过21年的患者中，传导性听力损失患者为19例（63.33%），混合性听力损失患者增加至5例（33.33%）。随着疾病持续时间的增加，平均听力损失和平均骨导阈值升高。在安全型慢性化脓性中耳炎且骨导阈值较差的患者中，受影响更明显的是高频段。
