FACTORS INFLUENCING OCULAR COUNTERROLLING

• Published in: JIBI INKOKA TEMBO Vol. 44; no. 6; pp. 457 - 465
• Main Authors: Kobayashi, Naoki, Sekiguchi, Chiharu, Ishii, Masanori, Yashiro, Toshinobu
• Format: Journal Article
• Language: Japanese
• Published: Society of Oto-rhino-laryngology Tokyo 2001; 耳鼻咽喉科展望会
• Subjects: long-term tilting; ocular counterroling; otolith organ function; visual field stimulatiton; wakefulness; 眼球反対回旋運動; 耳石機能; 視野刺激; 覚醒; 長時間傾斜
• ISSN: 0386-9687; 1883-6429
• DOI: 10.11453/orltokyo1958.44.457

Ocular counterrolling (OCR) is a vestibuloocular reflex originating in the otolith organs, especially in the utricle. We induced OCR in healthy volunteers by tilting the head and body to the right or left and quantitatively analyzed responses using image analysis. We studied the effects on OCR of tasks such as mental arithmetic, exercise in the upper extremities, long-term tilting, and visual field stimulation with random dots. Experiment 1 : The subject was fixed to a table and tilted at a constant velocity of 2 to a maximum angle of 60 degrees on the right or left. OCR responses were recorded in subjects who stared at a spot front of them without tasks. OCR responses were then recorded during either mental arithmetic or an exercise in the upper extremities. Mental arithmetic affected OCR and the symmetry of induced OCR was improved during the task. In contrast, exercise in the upper extremities did not affect OCR. Experiment 2 : Changes in OCR were monitored in subjects fixed for 20 minutes to a table tilted 45 degrees laterally. During long-term tilting, OCR changed in 1 group of subjects but not in the other. Experiment 3 : OCR responses were recorded under visual field stimulation (in the direction of gravity or in the longitudinal direction of the body) in subjects fixed to a table tilting laterally to an angle of 45 degrees. Ocular movements were also recorded under visual field stimulation 45 degrees oblique in subjects on the table without tilting. Visual field stimulation markedly affected OCR. Rotatory eye movements were induced by visual field stimulation alone. It became clear that OCR changes under different conditions because it was easily affected by central and visual input other than the otolith organ.