Symptom Fistula

The Fistula symptom is characterized by the appearance of nystagmus with an alternate increase and decrease in air pressure in the external auditory canal. This is a sign of limited purulent labyrinthitis, caused by the presence of a labyrinth fistula.

A labyrinthine fistula is an abnormal communication between the cavities of the inner ear and the middle ear. When the pressure in the external auditory canal increases, this pressure is transferred to the perilymphatic space of the labyrinth through the fistula. This leads to irritation of the semicircular canal receptors and the occurrence of nystagmus. A decrease in pressure causes nystagmus in the opposite direction.

Thus, the Fistula symptom indicates a violation of the integrity of the labyrinthine capsule and is an important diagnostic sign for diseases of the inner ear.