Your Audiology Tutorial: Patulous Eutachian Tube (PET)

The Eustachian tube runs between the middle ear space and nasopharynx, allowing the ear to drain fluid and equalize pressure. The tube, made up of bony and cartilaginous portions, opens and closes when a person swallows, chews, yawns, or changes altitude (ears "pop").  A patulous or patent (open) E. Tube (PET) is a disorder which can cause one to suffer abnormally loud levels of their own voice or breathing.  The tissues of the tube and/or the neighboring adenoids and tonsils are swollen.  Some causes of this abnormality: weight loss, pregnancy, fatigue, and radiation therapy.  Patients with Down syndrome tend to have a high incidence of PET.

Otolaryngologists (ENTs) will implement nasal endoscopy to examine the E. tube and nasopharynx. They can only see so much, usually limited to the pharyngeal opening; the lumen or tubal valve cannot be visualized.

A study by Andrew McGrath and Elias Michaelides, published in the Journal of the American Academy of Audiology in 2011, examined a group of twenty-five patients with suspected PET (and ten control subjects). Using the acoustic reflex decay option on an immittance bridge, it was found that certain conditions of testing would reveal excessive movement of the eardrum.  Measurements were taken while patient was breathing through their mouth only, their nose only, and through one nostril while the other was plugged.  The conclusion was that rarely will those with E.tubes functioning normally demonstrate eardrum movement above a certain metric.

Treatment of PET includes use of nasal sprays (steroidal or saline), though some advocate discontinuing the steroids and decongestants.