A manual of Eustachian tube function tests-illustration of representative test results obtained from healthy subjects and typical disorders with suggestion of the appropriate test method of choice.

In the 19th century, Politzer devised a method to measure passage of the Eustachian tube (ET) by pressurizing the nasopharyngeal cavity, which marked the beginning of the ET function test. Since then, various examination methods have been developed. While ET function testing is important, recent advancements in diagnostic imaging and treatments have renewed interest on its importance. In Japan, the main objective methods used for examining ET function include tubotympanoaero-dynamic graphy (TTAG), sonotubometry, and the inflation-deflation test. The Japan Otological Society (JOS) Eustachian Tube Committee has proposed a manual of ET function tests, which presents typical patterns of the normal ear and typical diseases and suggests the ET function test of choice for each disease. However, the diagnosis of each disease should be made based on a comprehensive history and various examination findings, with ET function tests playing a supplemental role in the diagnosis.

Diagnostic criteria for Patulous Eustachian Tube: A proposal by the Japan Otological Society.

Patulous Eustachian Tube (PET) is of increasing importance in otology. However, despite the abundance of diseases requiring a differential diagnosis from PET, such as superior semicircular canal dehiscence syndrome, perilymphatic fistula, acute low-tone sensorineural hearing loss, etc., there are currently no established diagnostic criteria for PET. In view of these circumstances, the Japan Otological Society (JOS) Eustachian Tube Committee proposed the diagnostic criteria for Patulous Eustachian Tube in 2012, in order to promote clinical research on PET. A revision was made in 2016, maintaining the original concept that the criteria should be very simple, avoid any contamination of "Definite PET" with uncertain cases. Moreover, it was also intended to minimize the number of cases that could be accidentally excluded even in the presence of some suspected findings ("Possible PET"). The criteria can be used by all otolaryngologists even without using the Eustachian tube function test apparatus. However, the use of such an apparatus may increase the chances of detecting "Definite PET". The algorithm for the diagnosis of PET using the criteria has also been described. The JOS diagnostic criteria for Patulous Eustachian Tube will further promote international scientific communication on PET.

[Patulous eustachian tube following otitis media].

Loss of weight, dehydration, pregnancy, fatigue, and otitis media are among the factors proposed as causes of a patulous eustachian tube, but true details remain obscure. We studied patients who developed a patulous eustachian tube following otitis media and discuss the relationship between these 2 conditions. Subjects were 12 patients diagnosed with otitis media at our department who later developed a patulous eustachian tube. The initial middle ear disease progressed from acute otitis media to otitis media with effusion in 2, acute otitis media in or acute mastoiditis in 1 each, and otitis media with effusion in the remaining 8 patients. Seven patients evidenced a low body mass index (BMI), weight loss, and underlying disease, but 5 with a patulous eustachian tube following otitis media did not. We retrospectively analyzed 119 patients diagnosed with a patulous eustachian tube in our department for whether they had been diagnosed by an ENT physician as having otitis media, i.e., acute otitis media or otitis media with effusion. Some 42 (35.3%) had a history of otitis media. At acute otitis media or otitis media with effusion, the tympanic cavity becomes inflamed, accompanied by inflammation of the eustachian tube mucosa and a stenotic tendency. Healing from otitis media is accompanied by decreased eustachian tube mucosa inflammation. We surmise that, depending on how inflammation disappears, fibrosis of the eustachian tube mucosa occurs, leading to a pathologically patulous eustachian tube. Many aspects of the causation of this condition remain unclear, but we surmised that in patients with earlier otitis media, a pathological patulous eustachian tube develops during resolution of inflammation. Our findings indicate the involvement of otitis media as a causative factors in a patulous eustacian tube.