Labyrinthine fistula

A labyrinthine fistula is an abnormal opening in the bony capsule of the inner ear, resulting in leakage of the perilymph from the semicircular canals into the middle ear. This includes specifically a perilymph fistula (PLF), an abnormal connection between the fluid of the inner ear and the air-filled middle ear. This connection is caused by a rupture of the oval window or round window that separate the inner and middle ear. Another type of l.f. is a semicircular canal dehiscence, which allows the inner ear to be influenced by the intracranial pressure directly.