Nystagmus

(redirected from horizontal nystagmus)
Also found in: Dictionary, Thesaurus, Medical.
Related to horizontal nystagmus: rotatory nystagmus, vertical nystagmus, cerebellar nystagmus

nystagmus

[nə′stag·məs]
(medicine)
Involuntary oscillatory movement of the eyeballs.

Nystagmus

 

an involuntary, rapid rhythmic oscillation of the eyeballs. The bilateral form of nystagmus is much more common than the unilateral form. Nystagmus can be lateral, rotatory, vertical, or diagonal, depending on the direction of the oscillations of the eyeball. The condition need not be pathological. For example, rotatory nystagmus can be induced in healthy persons who are revolving in a swivel chair, optokinetic nystagmus can result from fixing the eyes on moving objects, and caloric nystagmus can result when cold or warm water is poured into the ear.

Nystagmus is pathological when it results from a morbid condition in the vestibulocochlear nerve, in the vestibular nuclei of the brainstem, or in the labyrinth of the vestibular apparatus. Nystagmus can also result from a morbid process in the cerebellum, an inflammation of the inner ear, cerebrocranial traumas, infections and toxicoses of the brain, or neoplasms in the brain. In rarer cases, nystagmus is caused by eye diseases. Miner’s nystagmus is an occupational disease in miners who work with a pick under poorly illuminated and poorly ventilated conditions. Because these workers are constantly looking up or to the side, certain eye muscles become strained.

Nystagmus is treated by eliminating the underlying cause. In cases of miner’s nystagmus, the worker is transferred to jobs above the ground.

REFERENCE

Tsimmerman, G. S. Klinicheskaia otonevrologiia. Moscow, 1952.

V. A. KARLOV

References in periodicals archive ?
Subjects: Patients aged 18-80 years were eligible for enrollment if they had acute or subacute onset of severe, prolonged rotatory vertigo, nausea, and postural imbalance; horizontal nystagmus with a rotational component toward the unaffected ear and the head-thrust maneuver showed an ipsilateral deficit of the horizontal semicircular canal; caloric irrigation showed a lack of or hyporesponsiveness of the horizontal canal in the affected ear; and perceived displacement of verticality of the eyes rotated toward the affected ear without vertical divergence of one eye above the other.
His Hallpike test was again negative, but when he turned from the supine to the left or right lateral position, he became vertiginous and exhibited a horizontal nystagmus for 15 to 20 seconds; the nystagmus was accompanied by nausea but not vomiting.
The completely blind infant may have random multi-directional 'roving eyes', which should not be confused with the more rhythmical horizontal nystagmus.