Effect of perilymphatic pressure on the CM threshold in hydropic ears of guinea pigs

Abstract

The effect of perilymphatic pressure on the CM threshold was examined in 30 guinea pigs with endolymphatic hydrops. When a pressure of 300 mmH₂O was applied to the scala tympani of the basal turn, the 500 Hz CM threshold shift in hydropic ears was significantly smaller in the early stage than in normal ears, and it returned gradually to normal. The findings in the present study may be similar to the time course of the scala media pressure in hydropic ears; i.e. an initial increase, followed by a gradual decline towards normal.