![]() ![]() Aural fullness is a common symptom due to the build-up of negative middle ear pressure. Malignancy such as nasopharyngeal carcinoma can present with unilateral obstruction and must be excluded, with benign causes of obstruction including adenoidal hypertrophy and sequelae following adenoidectomy. Physiological causes of dilatory ETD involve the development of inflammation and mucosal edema, caused by episodes of rhinitis, upper respiratory tract infection, or gastro-oesophageal reflux disease, which leads to blockage of the orifice and dysfunction. This creates the reported symptom of autophony, with habitual ‘sniffing’ to help alleviate self-vocalization. Patulous ETD is caused by an overtly patent Eustachian tube, whereby the failed tube closure at rest provides continuous communication between the nasopharynx and the middle ear. By applying oral or topical decongestants for the treatment of baro-challenge induced ETD, it is thought that mucosal edema and local tissue hyperemia is reduced, thereby shrinking the nasopharyngeal mucosa and improving Eustachian tube patency. This affects the ability for subsequent attempts at opening and clearance. ![]() The stress imposed on the mucosal surfaces of the Eustachian tube by repetitive equalization maneuvers from the increased atmospheric pressure leads to localized inflammation and mucosal edema. Patients will have normal otoscopy and tympanometry findings, as the failure of tube opening is situation-specific and arise with increased atmospheric pressure, e.g., deep-sea diving or descent from altitude. īaro-challenge-induced Eustachian tube dysfunction describes the failure of the Eustachian tube to open with the surrounding pressure changes, thereby inhibiting the regulation of middle-ear pressure. It can be broadly categorized into baro-challenged induced, patulous, and dilatory ETD. ETD affects 1% of the population, with symptoms including aural fullness or 'popping sounds,' reduced hearing, tinnitus, autophony, otalgia, and imbalance. This categorizes as either acute (less than three months presentation) or chronic ETD (more than three months). Lastly, a functioning Eustachian tube protects the middle ear from loud sounds and potential hazards, including pathogens and secretions from the nasopharynx.Įustachian tube dysfunction (ETD) is the failure of the Eustachian tube in maintaining any of the three roles mentioned above. This consists of ciliated cells that clear inflammatory products and secretions from the middle ear and Eustachian tube, transporting them towards the direction of the nasopharynx for elimination. Secondly, it contains tube mucociliary transport. With the maintenance of middle ear pressure, tympanic membrane compliance is optimized for hearing. This has assistance from active mucosal gas exchange within the middle ear. Through the Eustachian tube's complex structure, it can carry out its three main functions:įirstly, by having a patent and open Eustachian tube, the pressure of the middle ear is equalized to that of the nasopharynx (i.e., towards atmospheric pressure). The tube opens on positive pressure, e.g., yawning, sneezing, swallowing, and the Valsalva maneuver, by contraction of the levator veli palatini and tensor veli palatini muscles. The medial two-thirds is fibrocartilaginous, opening out into the nasopharynx as a mucosal elevation known as the torus tubarius. It travels medially from the middle ear, directing down and forwards to open just posterior to the end of the inferior turbinate-the bony lateral third travels past both squamous and petrous portions of the temporal bone. The Eustachian tube, also termed the pharyngotympanic or auditory tube, is vital in regulating middle ear homeostasis, with complex anatomy designed to achieve this function.
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