Eustachian Tube Shadow – August 1, 2024
A 25-year-old male presents to a rural emergency department after being charged by a cow. The patient has right-sided chest pain, facial bruising lateral to the left eye, and an inability to close his right hand due to pain at the 4th metacarpal. Evaluation of the right ear with the Wispr Digital Otoscope reveals this image.
What is your diagnosis?
Based on the history presented in this vignette, you might expect a diagnosis of hemotympanum (blood behind the eardrum) from a basilar skull fracture. However, this eardrum is normal. In this clinical scenario, the darker area of the eardrum that is circled below might be confused with blood; it is actually the Eustachian tube orifice (tympanic cavity) seen on the other side of the semi-transparent eardrum.
For the eardrum to vibrate properly from sound waves, the pressure on both sides of the eardrum must be the same. This is accomplished by the eustachian tube which connects the middle ear to the posterior nasal cavity. Most of us have had the experience of “popping” our ears when descending in an airplane. This maneuver opens the Eustachian tube and allows the pressure on both sides of the eardrum to equalize. The Eustachian tube can become inflamed and unable to “open.” This causes ear pain from unequal pressure, often confused with acute otitis media.
Here is another case that shows a perforated tympanic membrane where the eustachian tube opening is clearly visible.
The patient, in this case, had a complete trauma workup including CT scans of the head, face, and neck. The only injury found was a fracture at his right 4th metacarpal. An ulnar splint was placed and a follow-up was arranged with orthopedics.
Here is the complete video exam
