![Sample our Medicine, Dentistry, Nursing & Allied Health journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5944/TOC-Subject-Sample-2021-Medicine-Dentistry-Nursing-Allied-Health.jpg"})
Abstract
In six persons with spontaneous vertical nystagmus behind closed eyes, concurrent horizontal nystagmus was induced by caloric irrigation of the horizontal semicircular canals in the vertical position. This procedure caused no change in the vertical nystagmus pattern. When the horizontal nystagmus subsided, the number of eye movements decreased, whereas the vertical nystagmus continued unchanged. The rapid phases of horizontal and vertical nystagmus invariably coincided even if the two types otherwise differed in frequency.
The mechanism eliciting nystagmus is discussed, the following conclusions being drawn: (1) the slow phase of horizontal and vertical nystagmus is controlled from separate independent centers; (2) the rate of the slow phase is influenced by both peripheral and central factors; (3) the rapid phase is elicited from a center common to horizontal and vertical nystagmus; (4) the mechanism of nystagmus is controlled from the extraocular muscle nuclei but may be affected by various centers.