Four years ago, a student physician assistant I will call Elena sustained blunt trauma to her right ear. Elena
was hit hard in the head in the emergency department while treating a college football player who had gotten quite drunk after his school's homecoming game.

Some four to six weeks after being hit, Elena began to experience buzzing in her right ear. She was provided with a complete diagnostic workup. A CT scan of her brain was unremarkable, with no visible lesions and no evidence of blood or hematoma. Subsequent evaluations by an audiologist indicated normal hearing acuity in each ear.

Yet the buzzing persisted, making Elena's daily life exceedingly difficult. A clinical psychologist ran a battery of neuropsychological tests, including a Minnesota Multiphasic Personality Inventory. But nothing shed any light on her situation.

Weary of all the tests and hampered by the perpetual buzzing, Elena came by my office. She asked if I had any suggestions as to what she should do. She was immensely frustrated.

I examined her right ear. The external auditory canal appeared normal, and the tympanic membrane was intact. However—and this was crucial—palpation of her right external ear revealed a probable post-traumatic arteriovenous (AV) fistula with continuous, palpable hum. I referred Elena to a vascular surgeon, who tied off and ultimately excised the AV fistula. Elena's chronic buzzing ceased.

Weeks later I received this note from her: “Doctor Josh, you were the first to examine my external ear thoroughly. I thank you. I might mention that the guy who hit me sent me one dozen Oriental lilies and one dozen long-stemmed red roses with a handwritten note of apology. He appears to be a nice guy when he is not drinking.”

It is always nice to receive such a thank you. As I wrote to wish Elena well, I wondered about the pathophysiology of her fistula. In reviewing the literature, I discovered the relative infrequency of such post-traumatic developments. These acquired AV fistulae are so uncommon—and so difficult to diagnose until complications arise—that they may be entirely missed by the health-care provider. Until the proliferation of new blood vessels in a compromised extremity produces an overload on the heart or an intravenous/intra-arterial rupture occurs, the fistula could easily escape notice. 

Elena's misfortune in the ED reminded me how blunt trauma can create an AV fistula—and that it is no small matter. Elena was lucky on two counts: She had a difficult-to-deal-with but minimally threatening auditory repercussion—nothing more. And she was well connected as a health-care professional, putting her in a position to seek help from a battery of sources. Many with congenital or acquired AV fistulae are not so lucky.

Dr. Grossman lives in the Tri-Cities area of northeastern Tennessee, where he has a primary-care practice.