What's your diagnosis? See p. 6.
Diagnosis: Patulous Eustachian Tube
By Michael J. Rensink, MD
Differential diagnosis is a science and an art. Clinical experience expedites the process and helps to rule out many possibilities. The absence of pain and conductive hearing loss and the presence of normal tympanometry and otoscopy in this case allowed me to rule out cerumen, infection, otosclerosis, and middle ear fluid.
The low-tone hearing loss and “plugged” sensation may suggest Meniere's syndrome, but there was no evidence of a balance disorder, low-pitched tinnitus, or any other symptom suggesting Meniere's.
The second set of tympanograms helps lead us to the correct diagnosis, a patulous Eustachian tube on the left. The Eustachian tube goes from the nasopharynx to the middle ear, providing air and pressure equalization to the middle ear. It is also a pathway to the outside for any fluid that might accumulate in the middle ear.
According to Shambaugh and Glasscock, “the walls of the cartilaginous Eustachian tube normally lie in apposition and part momentarily to admit air only on swallowing or yawning or when there is a slight increase in nasopharyngeal air pressure.” (Surgery of the Ear. Shelton, CT: PMPH-USA; 1980.)
The Eustachian tube normally rests closed. It opens briefly when we swallow, yawn, or perform a Valsalva maneuver. But the walls stay apart, and the tube is continuously open in the case of a patulous tube. The patient's voice travels up the Eustachian tube, and it takes on a booming or echoing quality in the middle ear.
When I want to perform a detailed study of the eardrum and Eustachian tube, I have the patient lie on an exam table, and use a binocular surgical microscope while I do pneumotoscopy. I can also watch the eardrum while the patient does the Valsalva maneuver. A healthy normal ear will distend when the patient inflates his ear, and this displacement of the tympanic membrane will stay there until the patient swallows or the Eustachian tube reopens. If the Eustachian tube is abnormally open (patulous), the TM will displace when the patient blows, and instantly drop back into resting position when the patient stops blowing.
A patulous Eustachian tube can also be documented with tympanomentry as was shown in Figure 3. Traditional tympanogram studies show us the mobility (compliance/admittance) of the eardrum at rest. Additional information can be obtained by having the patient hold his nose and blow lightly while the tympanogram is generated. If the Eustachian tubes are working normally, a moderately-light level of air pressure will open the Eustachian tubes and inflate the middle ear. If the Eustachian tubes are abnormally open, any change in nasal air pressure will be immediately reflected in a corresponding tympanogram where the peak of the tympanogram is shifted from the normal point (zero air pressure) to a positive point (e.g., 300 mm air pressure).
Education is my primary treatment for patients with this problem. I tell patients with this disorder not to pop their ears. We do not want to stretch the Eustachian tube continually. Patients should allow the normal opening of the Eustachian tube with swallowing and yawning to aerate the middle ear. The problem will usually resolve itself when the patient understands there is nothing seriously wrong with the ear. The problem is primarily a nuisance.
If the patient finds the problem difficult to live with, I will place a ventilation tube into the TM. Figure 4 shows the ventilation tube I placed in this patient's ear. The patient was pleased with sound of her voice and the absence of the hollow, plugged sensation following tube insertion.
Patients often report a plugged sensation in their ear when they sustain a hearing loss. The low-tone hearing loss in this patient's left ear could have been the cause of the plugged sensation, but the hearing loss had been present many years prior to her current complaint.
The plugged sensation is coming from the patulous Eustachian tube. It seems counterintuitive for a constantly open tube to create the plugged sensation, but the Eustachian tube normally rests closed with the air pressure equal on both sides of the tympanic membrane. This normal sensation has been present since birth and any variance from this condition, such as when there is fluid in the middle ear or a patulous Eustachian tube, may be sensed as a plugged ear.
A patulous Eustachian tube has been linked to hormones (Premarin), weight loss, overzealous use of the Valsalva maneuver (during flying, diving, or trips to the mountains), and upper respiratory infections.
Through the Otoscope: New and Improved
This month marks a new format for Through the Otoscope. This first page presents a diagnostic challenge with the patient's complaint, medical history, and initial findings. The reader's task is to arrive at a clinical diagnosis and propose a treatment. Medical situations are often complex so beware red herrings that make the case unique. Turn to the diagnosis page to see how your appraisal compares with the actual diagnosis. It is time to sharpen your diagnostic skills!
• Read Dr. Rensink's past columns at in the Hearing Journal archive at http://bit.ly/HJ-Archive.
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• Comments? Write to HJ at HJ@wolterskluwer.com.© 2012 Lippincott Williams & Wilkins, Inc.