Eustachian tube dysfunction is a common issue seen in patients with sinus infections, allergies and middle ear pathology. Eustachian tube is a narrow tube that connects back of the nose to the middle ear. Although normally closed, it does occasionally open up during swallowing, chewing and yawing. The primary function of this tube is to equalize air in the middle ear and drain out fluid from the middle ear. Inadequate functioning or blockage of this tube results in a condition called eustachian tube dysfunction. Symptoms generally include ear fullness, ear pain, muffled hearing and ringing in the ear.
Assessment:
The three common tests used to assess eustachian tube dysfunction include:
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Valsalva Test: This test involves obtaining three tympanograms. Initially, a regular tympanometry is performed to obtain the baseline tympanogram of the patient. Next, a valsalva maneuver is performed, where the patient is asked to close their mouth and nose and blow hard enough to cause their cheeks to puff up, allowing air to enter the ears. A second tympanogram is then obtained. If the eustachian tube is functioning normally, a peak pressure shift is observed in the tympanogram, indicating a positive pressure build up in the middle ear during the valsalva maneuver. To obtain the third tympanogram, the patient is asked to swallow several times. Normal functioning of the eustachian tube is confirmed if the pressure has returned to the baseline tympanogram.
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Toynbee Test: This test is similar to the valsalva test, with the only difference being that in this case, the toynbee maneuver is followed. The test is performed by instructing the patient to close the mouth and nose by pinching the nostrils and swallowing. Negative pressure in the middle ear indicates eustachian tube dysfunction.
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Inflation and Deflation Test: This test is based on the notion that a large amount of pressure in outer ear will cause slight change in middle ear pressure. The first step is to measure the baseline peak pressure. Next, a positive pressure of +400dapa is pumped into ear canal, which creates a positive pressure in middle ear. A second tympanogram is then obtained. To obtain a third tympanogram, the patient is asked to swallow several times. Normal eustachian tube functioning can be confirmed if the peak pressure is close to the baseline value. The Deflation test is similar, except that a negative pressure of -400dapa is pumped into the outer ear, which pulls back the eardrum, causing the middle ear volume to slightly increase. This significantly increases the peak pressure during second tympanogram.
