Ocular Rotation and Perception of the Horizontal under Static Tilt Conditions in Patients without Labyrinthine Function

Abstract

Bles W, de Graaf B. Ocular rotation and perception of the horizontal under static tilt conditions in patients without labyrinthine function. Acta Otolaryngol (Stockh) 1991; 111: 456-462.

In a previous study (1) it was found that in healthy subjects Ocular (Counter) Rotation is mainly due to otolith stimulation and only to a minor extent induced by slanted visual structures. Stimulation of the neck by tilting the trunk laterally upwards did not result in a systematic rotation of the eyes. in the present study it was found that subjects with bilateral loss of vestibular function showed a higher visually induced ocular rotation. Tilting the head (cervical stimulation) or the whole body (somatosensory stimulation) also led to a considerable OCR, demonstrating substitution of other sensory modalities for the loss of vestibular function. Estimates of the subjective horizontal were noisy, demonstrating the lack of an adequate gravitational reference signal.

Key Words:

• vestibular deficiency
• cervical stimulation
• somatosensory stimulation
• OCR