The disorder

Clinical features

The story is the diagnosis: dizziness and a drop in hearing that begin at a definable moment — a dive, a heave, a blow — and that flare with pressure and sound.

The cardinal features

Trainee

The cluster is: onset after a precipitant; fluctuating or progressive sensorineural hearing loss with tinnitus and fullness; vertigo and disequilibrium; and pressure/sound sensitivity (a positive fistula test, Hennebert or Tullio).1

Onset after a trigger. Symptoms begin around a pressure event — barotrauma from diving or flying, a forceful Valsalva or heavy lift, head trauma, or recent ear surgery. A 'pop' in the ear at the moment of injury is suggestive.

The fistula test

Applying pressure to the ear canal can provoke vertigo and a slow eye deviation — a positive fistula test (Hennebert sign). Try it:

pressureeyes at rest
Positive fistula test (Hennebert sign)
A positive test — pressure-evoked nystagmus or vertigo — supports a fistula, but it is neither sensitive nor specific (it is also positive in superior canal dehiscence and may be absent in a genuine fistula). Treat it as one strand of evidence, not proof.

The same pressure/sound sensitivity occurs in superior canal dehiscence, so a positive test is suggestive, not diagnostic. For how the evoked eye movements are seen and classified, see Nystagmus.

Key points

  • Onset around a trigger (barotrauma, strain, trauma, surgery) is the most useful clue.
  • Fluctuating/progressive SNHL with tinnitus and fullness, plus vertigo and disequilibrium.
  • Pressure/sound sensitivity (fistula test, Hennebert, Tullio) — suggestive but not specific.
  • Symptoms overlap heavily with Ménière’s disease.