Abstract
The purpose of this study was to determine if there was any difference in the characteristics of nystagmus in the physiological and non-physiological imbalance of the labyrinthine. Forty-one health subjects with no previous history of vestibulopathy were used in this study. A physiological imbalance was induced by the simultaneous stimulation of both ears with different temperatures (44° and 30°). Unilateral labyrinth stimulation at either 30° or 44° induced a non-physiological imbalance. In either condition, the deviation of the eyes from the midline and the maximal speed of the slow component of nystagmus were recorded with a CCD camera and a nystagmometer and the results were then compared. In nystagmus due to a non- physiological imbalance, the eyes deviated in the direction of the slow component, while no specific side deviation was noted in the nystagmus caused by a physiological imbalance. The maximal speed of the slow component was also higher in the latter condition. The characteristics of nystagmus in 10 patients with a unilateral labyrinthine dysfunction were also studied and were similar to those found in those patients with nystagmus due to a non-physiological imbalance, i. e., the eyes deviated in the direction of the slow component.
