Eustachian tube dysfunction
What is the Eustachian tube?
The Eustachian (pronounced you-stay-shun) tube is a tube that connects the back of the nose with the middle ear. It is a complex tube, made up of both cartilage and bone, and is a dynamic structure, that is, it does not remain in one state but can open and close through the action of muscles that surround it. These muscles mainly come from the nearby soft palate.
Why is the Eustachian tube important?
It functions is to ventilate the middle ear and keep it filled with air. When you pop your ears to equalize the pressure within them (for example when descending in an airplane or when scuba diving), you force air from the nose to the middle ear space. Air in the middle ear is important for normal hearing. If this space is filled with fluid (as in glue ear), then hearing loss can occur.
How does it work?
For brief periods of time, the entrance of the Eustachian tube at the back of the nose, which is usually closed at rest, opens to allow air to pass up into the middle ear. This usually happens when the soft palate stiffens during swallowing or yawning. When the soft palate stiffens, its muscles contract (flex) and pull the Eustachian tube entrance open. Chewing gum has a similar effect on the Eustachian tube.
What is Eustachian tube dysfunction?
This occurs when the Eustachian tube is abnormally closed for long periods of time and does not adequately ventilate the middle ear space, resulting in a variety of symptoms and problems related to the difference between the pressures in the middle ear and the outside environment. What symptoms and problems occur depends to a large extent on the severity of the dysfunction. Dysfunction may be temporary or long-lasting (chronic Eustachian tube dysfunction).
What causes it?
Eustachian tube dysfunction is still not fully understood and in the majority of cases, no cause can be found. However, there are some conditions that can cause or aggravate it.
In children, the Eustachian tube is shorter, wider and more horizontal than in adults. Its opening is also often blocked by adenoids at the back of the nose. These factors combined can lead to dysfunction that can in turn cause common childhood conditions such as glue ear and middle ear infections. Eustachian tube dysfunction is usually temporary in otherwise healthy children and they grow out of it in time as the tubes assume their adult shape.
People with Down syndrome or a history of cleft palate have a higher chance of developing long term Eustachian tube dysfunction due to abnormalities in the muscles of their soft palate or the shape of their Eustachian tubes.
Nasal congestion, as in rhinitis or in people with nasal polyps, can lead to congestion of the Eustachian tube opening, which can in turn cause problematic blockage.
What are the symptoms of Eustachian tube dysfunction?
In its mildest form, it may cause the feeling of having a blocked ear that you are unable to clear. People state that it feels like there is water in the ear or that the ear feels blocked up with cotton wool. The ear may then suddenly ‘pop’ and the symptoms disappear, only to return again. It may give the sensation of not being able to hear properly from the affected ear. Occasionally there may be associated pain or ringing in the ear (tinnitus).
What kinds of problems can chronic Eustachian tube dysfunction cause?
In many people, it remains a long-standing annoyance only and does not develop into problems. However, chronically poor ventilation of the middle ear can lead to the following conditions:
Glue ear – fluid accumulation in the middle ear causing hearing problems
Otitis media – middle ear infections
Retraction pockets of the ear drum – this occurs because of the vacuum that develops in the middle ear, causing the ear drum to collapse inwards. This may in turn lead to hearing loss or the development of cholesteatoma
Cholesteatoma – a skin cyst that forms in the middle ear due, in part, to a collection of dead skin within a retraction pocket of the ear drum. A cholesteatoma may cause chronic drainage from the ear, hearing loss and other serious complications.
What is a patulous Eustachian tube?
This is a type of Eustachian tube dysfunction where the mouth of the tube remains open for prolonged periods of time instead of remaining abnormally closed as in other forms of Eustachian tube dysfunction. Together with the symptoms of Eustachian dysfunction as described above, patients may also experience troublesome autophony (pronounced awe-toff-oh-nee), which is the sensation of hearing one’s own voice echoing in the ear while speaking. This occurs because voice is now able to travel up the open tube where it abnormally stimulates the hearing pathway. Breathing sounds and the heart beat may also be heard. Autophony can be very distressing and is the main symptom that people seek help for.
How is a problem with the Eustachian tube diagnosed?
The diagnosis is mainly based on the symptoms that are being experienced. In most cases, examination of the ear is normal, although some people may have signs of ear drum retraction, retraction pockets or even a cholesteatoma. In others, fluid may be seen behind the ear drum. Many tests have been devised to try to diagnose Eustachian tube dysfunction more accurately but none of these have proven to be very effective or accurate.
How is Eustachian tube dysfunction treated?
Unfortunately, there is no satisfactory treatment for Eustachian tube dysfunction. The good news is that most cases settle on their own with time. Many strategies have been tried, but none have been shown to be successful in every case. Sometimes a nasal steroid spray (such as Flixonase or Nasonex) is prescribed to try to calm the congestion around the opening of the Eustachian tube, especially in people with rhinitis or nasal polyps. Decongestant sprays and drops such as Otrivine or Sinex should be avoided as while they may give short term relief in some cases, they can aggravate the problem in the long term by causing rebound congestion.
Are there any operations that can help?
Ventilation tubes (such as grommets or T-tubes) are sometimes inserted across the ear drum to try to ventilate the middle ear through the ear canal, thereby bypassing the nose altogether. This form of treatment has mixed results, with one third of patients reporting relief, one third having no change in their symptoms and one third actually getting worse.
In very troublesome cases of a patulous Eustachian tube, other operations can sometimes be considered, such as cartilage tympanoplasty, which aims to stiffen the ear drum and reduce symptoms, or Eustachian tube obliteration, where the entrance of the Eustachian tube into the middle ear is blocked off so that abnormal sounds and voice cannot travel up into the middle ear. Again, neither offers a guarantee of success.
If the Eustachian tube dysfunction has resulted in problems such as glue ear, a retraction pocket or a cholesteatoma, then these can be separately treated as appropriate.
What does the future hold for Eustachian tube dysfunction?
There is currently research being done on the role of balloon tuboplasty for the treatment of Eustachian tube dysfunction (but not for patulous Eustachian tubes where it does not have a role). In this procedure, a deflated balloon is placed through the nose and up the dysfunctional tube where is inflated under very high pressures in an attempt to widen it and relieve the blockage. The long-term benefits of this are still being determined and may hold promise in the near future.
For more about glue ear, click here.
For more about otitis media (middle ear infections), click here.
For more about retraction pockets of the ear drum, click here.
For more about cholesteatoma, click here.
For more about tympanoplasty, click here.
For more about grommet or T-tube insertion, click here.