Autophony and the patulous eustachian tube.

Autophony and the patulous Eustachian tube is a real but rare clinical entity often misdiagnosed because the symptoms so mimic those of middle ear effusion. The diagnosis is made by the history of fullness or blockage and hearing ones own voice and breath sounds in the ear. The drum is usually atrophic and moves with respiration but this may not be visible. The usual past history is of weight loss. The diagnostic test is to observe a regular increase or decrease in middle ear pressure when increasing or decreasing the ambient pressure while measuring the impedance in a pressure chamber. The usual variations in pressure with opening and closing of the tube are not seen because the tube remains open all the time. Few patients need operative intervention and explanation is all that is usually required. When surgical treatment is necessary the application of 20% silver nitrate to the lumen of the tube on a wire covered by cotton has given results with few complications. Injection of Teflon paste anterior to the mouth of the Eustachian tube has been stopped by the manufacturer of the paste because of serious complications caused by the Teflon paste being accidentally injected into the internal carotid artery. Why some patients with a patulous tube and movement of the drug with respiration have no symptoms and other patients with very bothersome symptoms have so few objective signs and no movement of the drum, that can be observed with respiration, remains a mystery that needs further study.