Patulous Eustachian Tube: Part 1
This article describes a relatively little known otologic condition called Patulous Eustachian Tube. The symptoms often go unrecognized since the complaints may, and often do, mimic other ear conditions. This article discusses the assessment, differential diagnosis, and types of treatment currently being utilized for this often challenging condition. This disorder is sometimes described by Ear, Nose, and Throat (ENT) physicians as eustachian tube chronic patency. There are a variety of speculative reasons as to why this condition may occur in the first place. Yet, very little is currently offered as a definitive treatment protocol for the patient who suffers this malady. Reports of incidence (0.3-6%) are unreliable at this point. It is my opinion that the condition described in some circles as being “rare,” may only be “rare” to that reporting clinician, but not in the patient population. Goethe’s maxim, “What one knows, one sees” is universally true. For example, at one time reports of the phrase “disorders of the temporomandibular joint” were also considered “rare,” but now, 40 years later, the phrase brings chills to the insurance industry because of the appreciable incidence in the general population.
Most clinicians choose to leave the complexities of ear and nose and throat medicine to those who have specialized in the ENT field. Tumors of the deep lobe of the parotid or a condition such as Glomus Jugularis, are usually found by the combined skills of the radiologist and the ENT physician or neurologist. And, once in a while, we who are not radiologists, ENT, or neurology docs may get lucky and find ourselves having made a correct diagnosis in an area where we do not have specialized skills. As a dentist in pain management, I often say that I get lucky, or have beginner’s luck, when I am successful in area outside my professed expertise. For whatever the reason, we are surprised when a hunch—based on an educated guess—yields benefit for the patient.
Anatomy and Function
The eustachian tube, also known as the auditory tube or pharyngeotympanic tube, connects the nasopharynx to the middle ear. Most texts describe the tube at its proximal end extending from the anterior wall of the middle ear to the lateral wall of the nasopharynx. Typically the proximal one third of the tube is bone. And, the distal two thirds is cartilage with the distal end forming a tuber shaped end at the nasopharynx.
Most texts describe the tube as being 3 to 4 centimeters long.1 The inner wall of the tube also is coated with a mucous fluid that moistens the lining of the tube so that surface tension plays a partial role in the maintenance of closure. Closure or collapse of the tube is the norm and helps protects the ear from harmful sounds.2 Atmospheric pressure variations, swallowing, nose blowing, yawning, sneezing, and other maneuvers can cause the tube to open for a brief time. Such opening helps to accomplish the functions of ventilation, drainage, and protection.
The nerve supply to the eustachian tube is complex, and thus any discomfort may contribute to referred pain to other areas of the head and neck. There are four muscles associated with the tube. They include the tensor veli palatini, the levator veli palatini, the salpingopharyngeus, and the tensor tympani muscle. The tensor veli palatini is believed to play a role in active dilation of the tube by distention of the membraneous wall both laterally and inferiorly. The function of the levator veli palatini is believed to be dilation and support. The eustachian tube roles of the salpinogpharyngeus and tensor tympani are not clear at this time.
Pathology and Diagnosis
A pathologic condition can exist by which the tube remains open, or is patent, thus the phrase patulous eustachian tube. This state does not allow the air in the middle ear to equalize and can produce a variety of possible symptoms. Not the least of which is the possibility of fluid and bacteria entering and staying in the middle ear chamber.
There are a battery of tests the ENT doctor may utilize to examine and evaluate the condition of the eustachian tube. Some of the tests include otoscopy, pneumatic otoscopy, indirect nasopharyngoscopy, and endoscopy of the nasopharynx. Additionally, several maneuvers can be done: Valsalva test, Politzer test, and the Toynbee test. All three tests include visualization of the tympanic membrane with specific techniques unique to each.3
Symptomatically, the patient may present with a variety of signs and symptoms. Obviously, the patient cannot look into his or her outer ear to visualize the tympanic membrane to see what the doctor would observe. However the symptomatic patient often can hear their heartbeat in their ear, the sound of their nasal breathing, and sense of aural fullness. There also may be a popping sound, or clicking or clickity series of sounds as well. The patient may also experience some diminished hearing and, when speaking, may have a head-in-the-bucket resonance, or sound like someone speaking into a well to those listening.
If the patient lies down, they may often have a reduction in aural complaints or a temporary elimination of symptoms. If the patient puts their head between their legs in an upside position, the aural sounds almost always stop. Patients can also tilt the head to the side, or pinch the jugular vessel in the neck for a few seconds to momentarily stop the symptoms. The listing of patient complaints may not be complete because the condition is still a mystery concerning etiology. However, if the clinician uses an otoscope to visualize the tympanic membrane, it will be noted that the membrane moves outward with nasal expiration, and move inward with nasal inspiration. The membrane will also vibrate with talking and the patient hears their own voice and breaths echoing off the tympanic membrane. Further, the membrane will retract each time swallowing occurs. Additionally, the echoes sound too loud to the patient, and they sometimes describe hearing ocean waves as if putting a seashell up to the ear. Some patients hear ringing in the ear, distortion when talking, popping or a clicking sensation when swallowing, and roaring sounds. The patient’s voice often sounds lower or congested to other people because the open eustachian tube adds air volume in the pharynx.
The difficulty in trying to diagnose the patient without otoscopic exam of the tympanic membrane, simply leads to confusion and frustration. The patient is not by virtue of their vague or seemingly strange complaints irrational. They are simply an undiagnosed symptomatic patient with symptoms that can become frustrating and even hopeless. A hopeless patient is one who can choose to make irrational decisions, not the least of which are thoughts of self injury or worse may commit suicide.