Abstract
KCl and Ca2+ decreasing agents (Na2C2O4, Na-citrate, NaHCO3 and Na2EDTA) injected into the middle ear through the tympanic membrane or the facial nerve through the stylomastoid foramen provoked "Irritative Nystagmus". KCl presumably infiltrated into the perilymph and induced a slight increase of K+ concentration, resulting in decrease of the resting potential of the vestibular nerve or sensory cells in the vestibular labyrinth The solution of the Ca2+ decreasing agent might decrease Ca2+ in the perilymph and alter the excitability of the vestibular nerve or sensory cells in relation to Ca2+ stabilizing action. These effects of KCl and Ca2+ decreasing agents might be responsible for "Irrita-tive Nystagmus" due to continuous excitation of the vestibular nerve or sensory sensory cells. The relationship between these experimental results and the "Irritative Nystagmus" of Ménière's disease are dicussed in regard to K+ or Ca2+ concentration in the perilymph.
