Patulous Eustachian tube: Deep breath for a diagnosis

Abstract

Significance Statement: Eustachian tube disorders are common outpatient otologic presentations that can present a diagnostic challenge due to overlapping symptoms. This article will focus on patulous Eustachian tube, how the symptoms can overlap with those of Eustachian tube dysfunction, and the diagnostic insight offered by a close inspection of the tympanic membrane.

Case

A 23-year-old female with no prior otologic history presented for evaluation of pressure, popping, and autophony in the right ear. The symptoms began when the patient lost 30 lbs., worsened with exercise, and improved when the patient lay supine. The patient denied hearing loss, history of prior otologic surgery, family history of otologic conditions, or a history of sinonasal disorders. Binocular microscopy revealed well-aerated middle ears bilaterally and right tympanic membrane mobility with deep respirations (Video 1). Conservative and surgical therapies were discussed, and the patient opted for conservative therapy with nasal saline irrigations and hydration.

Discussion

The patient had a disorder of the Eustachian tube (ET). The two most common disorders are Eustachian tube dysfunction (ETD) and patulous Eustachian tube (PET). The ET is a structure that remains closed at rest and opens to allow equilibration of air pressure in the middle ear. ETD is the more common of the two and is characterized by dysfunction due to obstruction of the ET. PET, in contrast, occurs when the ET remains patent in the resting state. In both ETD and PET, the primary presenting symptoms can be pressure or a sense of fullness of the ears. This overlap can lead to misdiagnosis of PET as ETD. ¹

Making the distinction between these conditions is essential as therapeutic interventions vary. Intranasal corticosteroids and the Valsalva maneuver, paired with decongestant therapy, are conservative, initial management options for ETD. ² While decongestant therapy can worsen PET, hydration and nasal saline irrigations are conservative, first-line management options for PET. ³ Surgical interventions for ETD and PET are available and typically reserved for patients whose symptoms are not improved with conservative approaches.^{3 -6}

There are, however, some key features that may help differentiate PET from ETD and provide diagnostic insight. Significant weight loss can precede the development of PET by causing the Ostmann’s fat pad, fatty tissues surrounding the ET that help maintain the ET’s closure, to shrink. ⁷ Dehydration from vigorous exercise can reduce the water content of the Ostmann’s fat pad, also exacerbating PET symptoms. ⁷ When the patient is supine, dependent edema alters the patency of the ET, relieving the symptoms of PET.^3,7 We can observe these mechanisms at play in this patient vignette. Another clinically differentiating feature, if endorsed by the patient, is muffling of sound in ETD and autophony in PET.^3,4,8 Autophony could be described by the patient as the experience of hearing one’s own breathing, heartbeat, or speech. It occurs due to a patent ET permitting airflow that transmits to the tympanic membrane. This same airflow is observed as a mobile tympanic membrane during deep respirations. Visualization of this mobility with otoscopy serves as a key objective diagnostic feature for PET; these movements are absent in patients with ETD or a functional ET.^3,4,8

Thus, the patient’s presentation of unilateral ear symptoms exacerbated by exercise, improved with supine positioning, and associated with sudden weight loss are classic for PET. With this presentation, the movement of the tympanic membrane with deep respirations is diagnostic of PET.

Supplemental Material