caloric nystagmus

nystagmus /nys·tag·mus/ (nis-tag´mus) involuntary rapid movement (horizontal, vertical, rotatory, or mixed, i.e., of two types) of the eyeball.nystag´mic

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aural nystagmus  vestibular n.

caloric nystagmus  rotatory nystagmus induced by irrigating the ears with warm or cold water or air; see caloric test, under test.

Cheyne's nystagmus , Cheyne-Stokes nystagmus a peculiar rhythmical eye movement.

dissociated nystagmus  that in which the movements in the two eyes are dissimilar.

end-position nystagmus  that occurring in normal individuals only at extremes of gaze.

fixation nystagmus  that occurring only on gazing fixedly at an object.

gaze nystagmus  nystagmus made apparent by looking to the right or to the left.

gaze paretic nystagmus  a form of gaze nystagmus seen in patients recovering from central nervous system lesions; the eyes fail to stay fixed to the affected side with a cerebral or pontine lesion.

labyrinthine nystagmus  vestibular n.

latent nystagmus  that occurring only when one eye is covered.

lateral nystagmus  involuntary horizontal movement of the eyes.

opticokinetic nystagmus , optokinetic nystagmus the normal nystagmus occurring when looking at objects passing across the field of vision, as in viewing from a moving vehicle.

pendular nystagmus  that which consists of to-and-fro movements of equal velocity.

positional nystagmus  that which occurs, or is altered in form or intensity, on assumption of certain positions of the head.

retraction nystagmus , nystagmus retracto´rius a spasmodic backward movement of the eyeball occurring on attempts to move the eye; a sign of midbrain disease.

rotatory nystagmus  involuntary rotation of eyes about the visual axis.

spontaneous nystagmus  that occurring without specific stimulation of the vestibular system.

undulatory nystagmus  pendular n.

vertical nystagmus  involuntary up-and-down movement of the eyes.

vestibular nystagmus  that due to disturbance of the vestibular system; eye movements are rhythmic, with slow and fast components.

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caloric nystagmus

n.

A jerky nystagmus as part of Bárány's sign.

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caloric testing 

A neuro-ophthalmic technique in which cold and warm water is used to stimulate the vestibular system creating horizontal nystagmus (called caloric nystagmus or Barany's nystagmus). Cold water placed in the ear induces a fast-beating vestibular nystagmus with the fast phase moving away from the stimulated ear, while warm water causes the fast phase to move in the direction of the stimulated ear. The mnemonic COWS (cold-opposite, warm-same) is used to describe this effect. By placing the subject at a 30-degree upright position, heated or cooled water stimulates the now vertical horizontal semicircular canals.