Spontaneous eye motility following a unilateral vestibular lesion.

The strong imbalance of the output of vestibular nuclei, resulting from a hemilabyrinthectomy, causes among other postural and ocular symptoms, a failure to hold a steady ocular position in the dark. In this study the time course of the spontaneous eye motility following a right hemilabyrinthectomy was analyzed. In all animals, at the first recordings, drifts of 0.8-1.0 degrees/s were present. These drifts were directed to the lesion side, then they shifted their trajectory more than once. At the final recordings, most animals exhibited very slow drifts (0.05-0.1 degrees/s) directed to the intact side suggesting an overcompensation of the initial extreme rightward deviation.