The eVect of changes in perilymphatic K + on the vestibular evoked potential in the guinea pig

Abstract

To investigate the eVect on the functioning of the vestibular system of a rupture of Reissner's membrane, artiWcial endolymph was injected in scala media of ten guinea pigs and vestibular evoked potentials (VsEPs), evoked by vertical acceleration pulses, were measured. Directly after injection of a suYcient volume to cause rupture, all ears showed a complete disappearance of VsEP, followed by partial recovery. To investigate the eVect of perilymphatic potassium concentration on the vestibular sensory and neural structures, diVerent concentrations of KCl were injected directly into the vestibule. The KCl injections resulted in a dose-dependent decrease of VsEP, followed by a dose-dependent slow recovery. This animal model clearly shows a disturbing eVect of a higher than normal K + concentration in perilymph on the vestibular and neural structures in the inner ear. Potassium intoxication is the most probable explanation for the observed eVects. It is one of the explanations for Menière attacks. © 2010 Springer-Verlag.