Perilymph fistulas. Clinical criteria.

A perilymph fistula may be defined as an abnormal opening between the inner ear and the external surface of the labyrinth capsule, which allows the escape of perilymph and causes specific disorders of hearing, balance, or both. Its diagnosis remains somewhat controversial. This communication presents a defined set of clinical diagnostic criteria, the historic context by which those criteria have been developed, the histopathologic and clinical studies by which they have been challenged or substantiated, and the deficiencies that remain in our understanding of the pathogenic mechanisms that allow for abnormal cochlear or vestibular function.