A desirable animal model of acute hydrolabyrinth was made by injecting artificial endolymph into the cochlear duct of guinea pigs. In 12 animals with intact Reissner membranes, the endolymphatic potential kept normal after injection of artificial endolymph, but their ECochG showed a rise of SP amplitude, a decrease in AP amplitude, an increase of SP/AP ratio, and a delay of N1 latency. In 7 animals with ruptured membranes, the EP significantly decreased. ECochG showed a decrease in hearing in all test frequencies, a distortion of SP-AP wave or even a loss of AP. Based on the results of our experiment, it can be assumed that the dominant -SP may be seen in the acute stage of endolymphatic hydrops without a rupture of Reissner membrane. Therefore, the dominant -SP may only be of value in the clinical diagnosis during an episodic vertigo and fluctuating hearing loss in M?ni?re disease.
Animals Audiometry, Evoked Response