About Auditory (Eustachian) Tube Dysfunction

Auditory Tube. ©ADAM

What is the Auditory Tube?

The auditory tube, which is also sometimes called the eustachian tube, is a tiny tube that runs from the middle ear to the back of the throat (nasopharynx). The auditory tube has several important functions: it opens and closes in response to changes in ambient air pressure in order to equalize pressure in the middle ear, it may close in response to loud noises in an effort to protect delicate ear structures, and it clears mucus from the middle ear allowing it to drain into the back of the throat.

The auditory tube in children runs at a more horizontal angle than in adults. With age, the tube gradually becomes more vertical and larger in diameter allowing better drainage. This explains why children are more prone to conditions caused by auditory tube dysfunction. Under normal circumstances, the auditory tube is closed but opens periodically, specifically when we swallow, yawn or sneeze. This explains why you may need to swallow in order to "pop" your ears while driving up a steep mountain or taking off in an airplane. When you swallow your auditory tube opens and equalizes the pressure in your middle ear.

What is Auditory Tube Dysfunction?

Auditory tube dysfunction occurs when the auditory tube is unable to function properly. This can result in multiple conditions. The following conditions may occur when the auditory tube fails to equalize air pressure inside the middle ear space:

A rare condition called Patulous Eustachian Tube occurs when the auditory tube is unable to close at all but continually remains open.

Other conditions may result when the auditory tube is unable to properly clear mucus from the middle ear:

  • fluid in ears (also called serous otitis media, otitis media with effusion or glue ear)
  • middle ear atelectasis (adhesive serous otitis media)

What Causes Auditory Tube Dysfunction?

Multiple conditions can interfere with the normal function of the auditory tube. In the case of chronic auditory tube insufficiency, multiple factors are often involved. The following may cause the auditory tube to fail at one or more of its usual functions:

  • an auditory tube that is abnormally small in diameter (usually occurs in children)
  • an auditory tube that is blocked by enlarged tissue such as the adenoids (in children)
  • nasal congestion caused by allergies or infections such as a cold
  • rapid changes in ambient air pressure which do not allow the auditory tube sufficient time to equalize pressure inside the middle ear, for example descending too quickly while scuba diving, can lead to barotrauma of the ear
  • tumors or growths that block the auditory tube and prevent drainage (usually occurs in adults)

Symptoms

  • hearing loss
  • balance loss or dizziness
  • feeling like the ears are clogged or need to "pop"
  • while rare, some children with fluid in their ears may suffer from developmental delays such as delayed speech or delayed motor development

Diagnosing Auditory Tube Dysfunction

There are several methods for diagnosing the problems associated with auditory tube dysfunction as well as the root causes for auditory tube dysfunction. An ENT doctor, or otolaryngologist, is a specialist qualified to diagnose these types of conditions. A doctor will use your health history as well as any symptoms you report to help them in their diagnosis. An otoscope used to visualize the tympanic membrane (ear drum) is very helpful in diagnosing the function of the auditory tube. Changes in the appearance or mobility of the ear drum can often indicate fluid in the ear. A ruptured ear drum can also be visualized using an otoscope.

A fiberoptic endoscope inserted through the nose can be used to visualize enlarged tissues that may be blocking the auditory tube. It may also be possible to diagnose inflammation of the auditory tube or Patulous Eustachian Tube this way.

Tympanometry uses an electroacoustic impedance meter to assess pressure inside of the middle ear. High pressure is associated with auditory tube dysfunction. During the test, a probe is placed in the ear. The probe is not normally uncomfortable and could be compared to having your temperature taken in the ear. However, this test will yield erroneous results if you swallow, talk, or open your mouth during the test.

Other tests such as CT scans or MRI may also be used to visualize the auditory tube or to look for enlarged tissues or masses that may be blocking the tube.

Sometimes auditory tube dysfunction can be caused by allergies. An allergist, or immunologist, is a specialist who routinely diagnosis and treats allergies. Common tests for allergies include blood tests or a skin scratch test.

Treating Auditory Tube Dysfunction

Any treatments used for auditory tube dysfunction are selected based on individual circumstances and the root cause of the problem. In the case of fluid in the ear, many individuals are able to clear the fluid on their own after a period of time. If the fluid is still present after a period of 3-6 months, accompanied by bothersome symptoms, or affecting the development of a child, a doctor may choose to treat the fluid using the surgical placement of ventilation tubes. Removing the adenoids at the same time may be more effective than the placement of ventilation tubes alone.

Enlarged tissues such as adenoids, nasal polyps, turbinates or abnormal sinus growths including tumors that may be blocking the auditory tubes and preventing their drainage are often removed using endoscopic sinus surgery.

It is also important to treat any underlying conditions, such as allergies, that may be contributing to auditory tube dysfunction.

In the case of ear, barotrauma prevention is better than subsequent treatment. Make sure you descend and ascend slowly when diving, giving your ears plenty of time to adjust to the pressure. Swallow or yawn often when taking off in an airplane or driving up a steep mountain to clear your ears. Also, it may be helpful to take a decongestant such as pseudoephedrine before flying or diving. If you do experience barotrauma, a ruptured ear drum will usually heal itself in a few days. In severe cases, surgery may be necessary to repair the damage but this is the exception. You should also have any underlying allergies or sinus problems treated to prevent ear barotrauma.

Source:

Medscape. Eustachian Tube Dysfunction. Accessed: January 23, 2014 from http://emedicine.medscape.com/article/874348-overview#a1

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