The Otolith Organs And The Nystagmus Problem

Abstract

The material consisted of 35 cats which were divided into two groups. In one group a selective bilateral sectioning of the horizontal ampullar nerves was performed. Nystagmus did not occur in these animals. Tilting in either direction never provoked nystagmus. In the other group unilateral selective sectioning of the utricular nerve was performed. In all the animals a horizontal spontaneous nystagmus developed directed to the nonoperated ear. Tilting toward the operated ear increased the nystagmus frequency, whereas tilting in the opposite direction inhibited nystagmus. It was concluded that the utricle in itself never gives rise to nystagmus, but unilateral damage may readily induce a nystagmus that can be modulated by alterations in the influence of the gforces. This is owing to the intimate collaboration between the utricles and the semicircular canals.