Perilymph fistulas.

A perilymph fistula is an abnormal communication between the fluids surrounding the membranous labyrinth and the middle ear space. Because of the potential hazards of meningitis, permanent hearing loss, and occasionally incapacitating vestibular symptoms, early recognition and prompt repair of the perilymph leak is important. One hundred thirty three cases of perilymph fistulas are presented, stressing the clinical characteristics, evaluation, and management of patients with this otologic entity. The historical and contemporary literature on this subject is reviewed. A pathophysiological basis for perilymph fistula formation is presented, based upon certain anatomic, physiologic and mechanical principles involving the temporal bone and surrounding structures. For the purpose of publication, the Materials and Methods and Evaluation sections of the paper have been omitted. These are available from the author upon request in mimeographed form. The interested reader may wish to refer to items 80 and 133 in the Bibliography, previous publications by the author in which the bulk of the data used in the omitted sections can be found.