The perilymphatic fistula: the end of an enigma?

While the existence of a perilymphatic fistula may be suggested on the basis of a patient's history and physical findings, at present the diagnosis can only be established by the identification of the actual fistula at the time of tympanotomy. In some cases, repeated reaccumulation of clear colorless fluid within the middle ear is interpreted as representing perilymph and has been considered to indicate the presence of a fistula that cannot be visualized. This subjective type of observation is made by the operating surgeon and is consequently subject to bias. At the present time there is no objective method, such as histopathology, to confirm the diagnosis of a perilymphatic fistula in this type of situation. As a result, there is some variation and controversy in the otology literature as to what surgical findings at tympanotomy should be considered as "proof" of a perilymphatic fistula. In this paper we will propose a new method for confirmation of the diagnosis of perilymphatic fistulas based on a unique biochemical property of perilymph.