Effects of an anti-cholinergic on the function of patulous eustachian tube

Diagnosis and treatment of patulous Eustachian tube

Symptoms of patulous Eustachian Tube (PET) were first described by Jago in 1858 and reported by Schwartze in 1864, recognizing PET as a clinical entity. This review summarizes the causes, epidemiology, diagnosis, and treatment of PET, with a particular emphasis on diagnosis and treatment, detailing the diagnostic criteria and silicone plug (Kobayashi plug) surgery proposed or developed in Japan. PET is often linked to weight loss from chronic illnesses, dieting, anorexia nervosa, hemodialysis, and bariatric surgery. It is also associated with pregnancy, oral contraceptive use, nasopharyngeal and muscular atrophy or scarring, and neuromuscular diseases. Interestingly, many PET cases lack an identifiable cause. The prevalence of PET ranges from 0.3 % to 7.0 %, with a higher incidence in females and typically occurring in adolescents and adults. Diagnosis relies on a combination of clinical history, physical examination, ET function test, and imaging. The Japan Otological Society (JOS) proposed standardized diagnostic criteria, where a "definite PET" diagnosis requires all three criteria (aural symptoms, tubal obstruction procedures, and objective findings), while "possible PET" requires two. Treatment includes conservative and surgical interventions. For persistent and severe cases that do not improve with conservative treatments, surgical options are explored. These surgical procedures are classified by the type of intervention, which includes tympanic membrane manipulation (such as tympanostomy tube insertion and mass loading of the tympanic membrane), plug surgery, ET injection, shim surgery, tuboplasty, and ET closure. The Kobayashi plug, a 23 mm long silicone plug, is specifically designed for PET treatment. Indications for its use include "definite PET," a PHI-10 score of 26 or higher, and lack of improvement after six months of conservative treatment. Preoperative evaluations include CT scans to assess ET patency and confirm the bony portion. Surgery, mostly performed under local anesthesia, involves inserting the plug into the ET via a myringotomy, ensuring the correct size and position with endoscopic guidance. In conclusion, PET is a challenging condition with diverse etiologies and symptoms. Effective management requires a comprehensive diagnostic approach and tailored treatment plans, with the Kobayashi plug offering a promising solution for refractory cases. Further research and advancements in diagnostic techniques and therapeutic interventions will continue to enhance the management of PET.

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 approaches to and management options for patulous eustachian tube

Objectives:

To systematically review the literature and to summarize all evidence related to the diagnosis and management of patulous eustachian tube.

Methods:

The present study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results:

Overall, 59 articles were retrieved and included in the analysis. Studies investigating treatments enrolled 1279 patients collectively, with follow-up duration varying from few days and up to 2 years. Eight studies reported medical treatments with intranasal saline instillation as the most frequently studied option. Other studies reported various surgical treatments varying from simple tympanostomy to invasive procedures targeting the orifice of the ET or the anatomical features surrounding it. In addition, 10 studies including 367 subjects investigated different diagnostic methods.

Conclusion:

Currently, there is a wide spectrum of diagnostic and therapeutic interventions with minimal clinical efficacy, a persistent lack of systematic guidelines, and several gaps in previous research endeavours.

PROSPERO REG. NO. CRD: 1644000

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.

Successful Treatment of Autophonia with Botulinum Toxin: Case Report

Objectives:

We sought to treat autophonia due to a patulous eustachian tube using botulinum toxin.

Methods:

Because we assumed that the patulous eustachian tube was caused by abnormal activity of paratubal muscles (tensor and levator veli palatini muscles and salpingopharyngeus muscle), paralysis was performed via injection of botulinum toxin type A in a 45-year-old female professional musician who had had chronic unilateral autophonia for 20 years. In addition to a patient interview, an endoscopic examination of the nasopharynx (posterior rhinoscopy), ear microscopy, and impedance audiometry were performed to verify the diagnosis and the outcome after treatment.

Results:

The autophonia disappeared 1 week after treatment. Normalized tympanic ventilation was verified by impedance audiometry after 8 weeks. The period of symptom relief was 9 months.

Conclusions:

The administration of botulinum toxin type A provides a new option in the treatment of patulous eustachian tube. The reliability of this method and the effect of repeated injections remains to be proved in future studies.

[The patulous eustachian tube-novel surgical approaches]

A patulous eustachian tube (tuba aperta) may lead to an enormous reduction in quality of life. A patulous eustachian tube can cause symptoms such as autophony, breath synchronous tinnitus, pressure sensation in the ear, and hearing loss. In combination with so-called "sniffing", it can trigger the development of cholesteatoma. Due to the diffuse symptoms the correct diagnosis of this disease can be challenging. A patulous eustachian tube can be best diagnosed through a well-structured examination including patient history, physical examination with thorough observation of movements of the tympanic membrane, and tympanometry with reflex decay. This publication reviews recent literature on the patulous eustachian tube. We focused on the evaluation of the different surgical strategies such as the patulous eustachian tube reconstruction, the Kobayashi plug or the injection of Vox® implants into the torus tubarius.

A model of active Eustachian tube function in the rat: effect of modulating parasympathetic innervation

The effect of altering secretion into the Eustachian tube by modulating cholinergic innervation was studied in the anaesthetized rat. Active properties of the Eustachian tube were determined by measuring the ability of reflex-induced swallowing to equalize against an increased pressure level in the bulla. Reflex-induced swallowing was initiated by electrically stimulating the superior laryngeal nerve. Passive properties of the Eustachian tube were determined by increasing middle ear pressure until the Eustachian tube spontaneously opened. Blocking cholinergic neurotransmission with atropine had no effect on active or passive properties of the Eustachian tube. Potentiating cholinergic neurotransmission with neostigmine significantly impaired the ability of active swallowing to equilibrate middle ear pressure, but had no effect on passive properties of the Eustachian tube. The findings show that cholinergic nerve transmission, most likely from the parasympathetic division of the autonomic nervous system, can influence Eustachian tube function. We hypothesize that this effect is due to changes in surface tension in the Eustachian tube as a result of changes in secretion.

Sonotubometry with a tubal catheter as an index for the use of a ventilation tube in otitis media with effusion

Insertion of a ventilation tube is considered to be an effective treatment for otitis media with effusion (OME), although it may entail complications such as residual perforation and poor hearing after tube extrusion. In order to reduce problems associated with ventilation tubes, we examined the Eustachian tube function in 25 adults with OME by two methods. One was a sonotubometric measurement (sonotubometry) with both a tubal catheter and a nasal olive tip, and the other was an air-pressure equilization method (deflation test). Sixty percent of the ears showed poor tubal function in both types of sonotubometry. The number of negative cases in sonotubometry with a tubal catheter was higher in ears with a larger volume of effusion, and in ears with poor tubal function by deflation testing. Judging from the volume of effusion and results of the deflation tests, the prognosis could be fairly good in many positive cases. We conclude that sonotubometry with a tubal catheter is useful in the management of OME, especially in evaluating the efficacy of ventilation tubes.