Perilymph fistula

Abstract

The phenomenon of a position-dependent fluctuation of hearing loss, in patients subsequently found to have perilymphatic fistula, is reported. Eleven patients with rupture of the oval or round windows of the labyrinth showed a lowering of thresholds on audiometry after lying horizontally for 30 minutes with the affected ear uppermost. It is suggested that air had entered the membranous labyrinth, interfered with transmission of footplate vibration to the perilymph column, and was displaced by this manoeuvre to produce a small, measurable, hearing gain, The diagnostic and prognostic significance of this finding is discussed.