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Eustachian Tube Patency
ALTERNATIVE NAMES: Patulous eustachian tube.
DEFINITION: A eustachian tube which is continually open.
WHAT IS GOING ON IN MY BODY? The eustachian tube is a structure that goes from the space behind the eardrum and empties into the backmost part of the nasal cavity. It is a bony canal which as it progresses through the base of the skull transitions to a cartilage tube near the back of the nasal cavity. It has a mucous membrane lining that has self-cleaning capabilities. The normal eustachian tube is closed at its opening into the nasopharynx and is opened by contraction of muscles in the palate during the act of swallowing, yawning, or forward jaw movement. Its opening allows maintenance of equal pressure across the eardrum. In a patulous eustachian tube, the eustachian tube is constantly open. As a result, there is greater ease of infected nasal and sinus secretions to move from the nasophaeynx up into the middle ear space and thus cause acute ear infections. It is thought that a patulous eustachian tube is the main cause for chronic ear disease in individuals with Down's syndrome. Individuals with a patulous eustachian tube have no difficulty at all equalizing ear pressure on descent because the tube is not closed off.
WHAT ARE THE SIGNS AND SYMPTOMS? Those with a patulous eustachian tube often complain of a sensation of ear plugging or fullness that very transiently improves with popping the ear. They may complain that it is hard to modulate the volume of their own speech, that their speech has an echo quality, or it sounds as if they are speaking in a barrel, and they may hear the air moving through the nasopharynx as they breathe through their nose. When these individuals are examined, the ear canal, eardrum, and air space behind the eardrum are usually normal. The main way in which this is diagnosed is having the patient forcefully breathe in and out through the nose while examining the affected ears. In the case of a patulous eustachian tube, the pressures generated during breathing are transmitted through the middle ear space to the eardrum, and therefore, the eardrum moves in and out in concert with respiration. Patients often complain that their symptoms are worse later in the day than in the morning. This results from a natural swelling of the mucous membranes within the nose and sinuses when people lie down. As a result of this swelling, there may be some temporary closure of the eustachian tube so that it functions more normally. However, as the swelling resolves as the individual is up, then the symptoms appear.
WHAT ARE THE CAUSES AND RISKS? In most cases the cause is not clear. The most consistent association is excessive weight loss. It is thought that loss of fat tissue around the eustachian tube allows it to be consistently open. Radiation therapy may create this in some individuals, and in Down's syndrome patients there may be an abnormality in eustachian tube anatomy and palate function. There are no significant risks associated with a patulous eustachian tube.
HOW TO PREVENT THE DISEASE: Unfortunately, since in most cases there is no clear cause, there is no clear means of preventing it.
HOW IS IT DIAGNOSED? The main form of diagnosis is physical examination and identification of an eardrum that moves in concert with nasal respiration. Sometimes a tympanogram may be helpful. A tympanogram indirectly measures the pressure behind the eardrum. Since the pressure changes with nasal respiration, instead of a smooth bell curve pattern that would normally represent eardrum movement, the eardrum movement pattern will assume an ascending/descending stair-step-like pattern.
WHAT ARE THE LONG-TERM EFFECTS? Most of the long-term effects are the annoying symptoms.
AM I PUTTING OTHERS AT RISK? No.
WHAT ARE THE TREATMENTS? Unfortunately, there is no adequate treatment. Some individuals respond to nasal steroid sprays. The concern with using any medications, such as oral or topical decongestants or nasal steroids, which can reduce mucous membrane thickness, is that these agents could actually exacerbate the problem. Some individuals may respond to placement of a tube in the eardrum. In some more severe cases, injection of Teflon under the lining of the eustachian tube opening may serve to close it. In certain extreme cases plugging the eustachian tube surgically by lifting up the eardrum and placing a plug into the middle ear opening of the eustachian tube may be helpful. Certain Chinese herbs have been touted as effective treatments, but that has certainly not been true in my experience. Regaining weight may help those in whom weight loss is the cause. Lastly, some may have the process spontaneously resolve.
WHAT ARE THE SIDE EFFECTS TO THE TREATMENTS? The main side effects that can occur from placement of a pressure equalization tube would be getting an infection if soapy or contaminated water were to enter through the opening in the PE tube. When the PE tube falls out, about 3% of individuals may have a leftover hole in the eardrum. For the individual who has severe enough symptoms to desire permanent obstruction of the eustachian tube, even with a PE tube in the eardrum, there is concern that a chronic middle ear or mastoid inflammation or infection may result.
WHAT HAPPENS AFTER TREATMENT? If treatment is successful, then the patient's symptoms should resolve.
HOW DO I MONITOR THE DISEASE? The main form of monitoring the disease process is the degree of symptoms.
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