Positive "fistula sign" with an intact tympanic membrane. Clinical report of three cases and histopathological description of vestibulofibrosis as the probable cause.

Abstract

Three patients had a positive "fistula sign," or "Hennebert sign," with intact tympanic membranes. Two had symptoms typical of Meniere disease. All three were shown to be free of congenital syphilis. Labyrinthectomy was performed for one patient, and the extracted stapes sectioned. This revealed part of the membranous labyrinth firmly adherent to the medial surface of the footplate. This histopathological finding is herein named "vestibulofibrosis." Study of unrelated pathological specimens selected from the temporal bone collection of the Massachusetts Eye and Ear Infirmary revealed that vestibulofibrosis is a finding common to several postinflammatory or progressive inner ear disease processes, including congenital syphilis, viral labyrinthitis, and Meniere disease. Such fibrous adhesions between the footplate and membranous labyrinth are suggested as the pathological basis for the positive fistula sign in the presence of an intact tympanic membrane.