RESUMO
Objective: To analyze the etiology, diagnosis, and treatment of unexplained conductive hearing loss (UCHL) with intact tympanic membrane. Methods: A systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 642 articles were retrieved from databases such as PubMed, Embase, Web of Science, and Cochrane. Fifty-four research articles and 21 case reports were screened out according to the inclusion and exclusion criteria for analysis of the etiology of UCHL. Seven research articles with UCHL who underwent exploratory tympanotomy were selected for data extraction and analysis of clinical characteristics. Results: UCHL is a common manifestation of various diseases, including congenital ossicular anomalies (COA), otosclerosis (OTS), congenital middle ear cholesteatoma (CMEC), oval window atresia, superior semicircular-canal dehiscence, congenital stapedial footplate fixation, middle ear osteoma or adenoma, congenital ossification of stapedial tendon, and so on. A total of 522 patients were included in the 7 articles; among whom OTS showed a tendency to increase with age. The main symptoms were hearing loss, followed by tinnitus, dizziness, ear fullness, ear pain, facial paralysis. A total of 87.5% to 93.0% patients with COA manifested as nonprogressive deafness that occurred since childhood, with tinnitus incidence of 15.6% to 30.2%, and 86.4% to 96.4% patients with OTS presented with progressive hearing loss, with tinnitus incidence of 60.1% to 90.9%. The diagnosis positive rate of high-resolution computed tomography (HRCT) was 33.8% to 87.1%, and CMEC was higher than that of COA (83.3%-100% vs 28.6%-64%). All the articles reported good hearing recovery. The most common surgical complications included taste abnormalities, tinnitus, and dizziness. Conclusion: UCHL presents with similar clinical manifestations and poses challenges in preoperative diagnosis. Exploratory tympanotomy is the primary method for diagnosis and treatment, with good prognosis after removing the lesion and reconstructing hearing during the operation. Children can also safely undergo the surgery.
RESUMO
Eustachian tube dysfunction (ETD) is a condition where the Eustachian tube (ET) fails to function normally, resulting in symptoms such as aural fullness, tinnitus, autophony, and hearing loss. ETD can further lead to middle ear diseases such as otitis media effusion and adhesive otitis media, which is becoming more common in the field of otology. Although the pathogenesis of ETD remains unclear, recent animal studies and clinical experiments have found allergic reactions and allergic diseases are closely related to the occurrence of ETD. As the mucosa of the ET is continuous with that of the nasopharynx and tympanic cavity, it is reasonable to assume that the immunological basis of the ET itself is similar to that of respiratory allergic diseases. However, due to the special anatomical location and complex pathogenesis of the ET, there is still no unified diagnostic gold standard. Additionally, there is an ongoing debate regarding whether ETD can be classified as a distinct disease or even an allergic disease. Furthermore, the effectiveness of anti-allergic therapy in patients with ETD is yet to be fully understood. Therefore, this review elaborates on the possible mechanisms of allergic reactions in the occurrence and development of ETD, and explores the potential role of anti-allergic therapy in managing this condition, in order to provide new insights into the pathogenesis and prevention of ETD.