Use of the Torsion Swing Test in a Follow-up Study of the ENG Registration in Cases of Unilateral Labyrinthectomy

Abstract

Using the damped swing torsion test and in order to follow and to analyse the evolution of the compensation phenomenon, frequency nystagmograms were registered regularly on a series of patients who underwent a unilateral labyrinthectomy for Ménière’s disease. The electronystagmographical curve permits checking of the evolution of the spontaneous nystagmus at rest and of the nystagmus responses to ampullopetal and ampullofugal endolymphatic flow stimulation of the undamaged labyrinth. The appearance of the compensatory nystagmus does not seem to be absolutely connected with the disappearance of the spontaneous nystagmus. According to the course of time, a slight reduction of the ampullopetal effect is noticed. There especially appears a very clear increase of the frequency of the compensatory nystagmus during ampullofugal stimulus. This can be noticed as well during the presence of the spontaneous nystagmus as after its disappearance. Besides the establishment of a nuclear compensation, other factors (efferent factors) seem to be involved, which influence the ampullopetal effect on the undamaged vestibulum.