The Eustachian tube is a small passage connecting the middle ear space to the back of the nose, or nasopharynx. This tube, which is approximately 35 millimeters long in adults, plays a regulatory role by equalizing air pressure between the middle ear and the outside atmosphere. This function is necessary for the eardrum to vibrate correctly and transmit sound effectively. Normally, the Eustachian tube remains closed, opening briefly when a person swallows, yawns, or chews to allow for pressure equalization.
Patulous Eustachian Tube (PET) is a condition where this passage remains abnormally open or patent, instead of staying closed at rest. This persistent opening allows an uninterrupted column of air and sound to travel directly from the nasopharynx to the middle ear. The resulting disruption in the ear’s normal mechanics leads to the characteristic and often distressing auditory symptoms experienced by those with PET.
The Mechanism of Patulous Eustachian Tube (PET)
The normal function of the Eustachian tube relies on a precise interplay of tissue, pressure, and muscle action. The tube is mostly cartilaginous and depends on surrounding soft tissues and the intrinsic elasticity of its lining to keep it closed. It opens temporarily when the tensor veli palatini muscle contracts during activities like swallowing or yawning, which pulls on the tube’s wall to dilate the passage and allow air exchange.
In a person with PET, the tube’s protective closure mechanism is deficient, causing it to remain continuously or intermittently open. This abnormal patency allows pressure changes from the upper airway, such as those caused by breathing, to be transmitted directly into the middle ear. The lack of a proper seal means the tube cannot protect the middle ear from unwanted sounds and pressure fluctuations originating from the body.
The integrity of the surrounding tissue, particularly a small fat pad, is important in maintaining the collapsed state of the tube’s cartilaginous portion. When this tissue support is lost, the tube fails to close completely. This creates a direct path between the nasal cavity and the middle ear, transmitting sound waves and air pressure directly to the eardrum.
Recognizing the Key Symptoms
The most distinct symptom of Patulous Eustachian Tube is autophony. This phenomenon is the amplified hearing of one’s own voice, breathing, or other internal body sounds, often described as shouting in one’s own head or speaking into a barrel. The open tube allows these self-generated sounds to resonate directly against the eardrum, making it difficult to attend to external environmental sounds.
Another common complaint is a persistent feeling of aural fullness or pressure in the affected ear, which can mimic the sensation of a blocked ear. Patients may also experience tympanophonia, the audible sensation of their own heartbeat or the sound of air moving in and out of the nose during respiration. These symptoms can be highly disruptive, sometimes interfering with speech production and concentration.
Symptoms of PET often fluctuate and are exacerbated by physical exertion, such as exercise, or by periods of dehydration. Conversely, many people report a temporary improvement when they lie down, a change thought to increase blood flow and congestion in the tissue surrounding the tube, helping it close. The constant transmission of pressure changes may also cause the eardrum to move synchronously with breathing, which a physician can observe during an examination.
Common Causes and Contributing Factors
While the exact reason for the development of PET is often unknown (idiopathic), several factors are strongly linked to the condition. A significant or rapid reduction in body weight is a commonly cited cause, associated with a loss of the protective fat padding that helps keep the Eustachian tube closed. This reduction in peritubal tissue pressure allows the tube to remain open more easily.
Other factors that contribute to PET include:
- Chronic dehydration, which reduces the bulk of the mucosal lining of the tube.
- Hormonal fluctuations, such as those experienced during pregnancy or with the use of hormonal therapy. High levels of estrogen may affect the surface tension and tissues around the tube.
- Certain medications, including diuretics (which cause dehydration) and nasal decongestant sprays (which dry out the mucosal lining).
- Neurological disorders that cause muscle atrophy, or chronic conditions like stress and anxiety, which affect the muscles surrounding the Eustachian tube, such as the tensor veli palatini.
Diagnosis and Treatment Options
Diagnosing Patulous Eustachian Tube relies on a combination of patient history, physical examination, and objective testing. During a physical examination, a doctor may observe the eardrum (tympanic membrane) moving visibly with the patient’s breathing. This movement is often more pronounced when the patient is asked to breathe forcefully or occlude one nostril.
Specialized tests help confirm the diagnosis. Tympanometry measures the mobility of the eardrum in response to pressure changes; a diagnosis is supported if a brisk inspiration causes a significant pressure shift detected by the tympanogram. Nasopharyngoscopy, where a flexible scope is inserted through the nose, allows the physician to directly visualize the opening of the Eustachian tube to check for abnormal openness during normal respiration.
Management begins with conservative, non-invasive strategies aimed at increasing the bulk of the surrounding tissues or the tube lining. Simple measures include ensuring sufficient hydration and avoiding known triggers like decongestant nasal sprays or excessive caffeine consumption. Physicians may also recommend techniques to increase nasal moisture, such as using saline nasal rinses, or encouraging the patient to lie down when symptoms are severe.
If conservative methods fail, medical and surgical options are considered. Medical treatments involve topical applications, such as specific nasal drops designed to swell the mucosal lining of the tube. In persistent and severe cases, various surgical interventions are explored to physically narrow or bulk the opening of the tube.
Surgical approaches include:
- Injection of bulking agents, such as fat or other materials, near the tube opening to help it close.
- Insertion of a ventilation tube (grommet) into the eardrum, which can relieve aural fullness for some patients.
- Insertion of a silicone plug, such as the Kobayashi plug, to physically narrow the tube.
- Other methods utilized to permanently close or shim the tube to restore its normal, closed state.