Biomaterial Database

Pseudocaloric nystagmus. 1978

G D Becker, and J L Davis, and J Parell

Pseudocaloric nystagmus (PCN) is an appropriately beating nystagmus induced by cold caloric irrigation of an ear with abolished vestibular function. The nystagmus is not the result of endolymph flow but probably represents unmasking a latent nystagmus by altering the patient in this case, through tactile (caloric) stimulation. Pseudocaloric nystagmus has the following characteristics: (1) mild intensity (eyes closed-slow phase velocity usually less than 8 degrees/sec), it has not been observed with the eyes open, (2) always beats away from the diseased ear; therefore, any nystagmus induced by cold irrigation will be appropriately (contralateral) beating while that induced by warm irrigation will be inappropriately (contralateral beating; 3) the induced nystagmus will not reverse direction after inverting the ampulla. Establishing bidirectional sensitivity of the cupula by demonstrating appropriately beating nystagmus to ampullopetal and ampullofugal flow of endolymph not only assures that the lateral semicircular canal (SCC) is functionally intact to caloric stimulation but will avoid errors in electronystagmorgraphic (ENG) interpretation.

UI	MeSH Term	Description	Entries
D009759	Nystagmus, Pathologic	Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. (Adams et al., Principles of Neurology, 6th ed, p272)	Convergence Nystagmus,Horizontal Nystagmus,Jerk Nystagmus,Pendular Nystagmus,Periodic Alternating Nystagmus,Rotary Nystagmus,See-Saw Nystagmus,Vertical Nystagmus,Conjugate Nystagmus,Dissociated Nystagmus,Fatigable Positional Nystagmus,Multidirectional Nystagmus,Non-Fatigable Positional Nystagmus,Permanent Nystagmus,Rebound Nystagmus,Retraction Nystagmus,Rotational Nystagmus,Spontaneous Ocular Nystagmus,Symptomatic Nystagmus,Temporary Nystagmus,Unidirectional Nystagmus,Non Fatigable Positional Nystagmus,Nystagmus, Conjugate,Nystagmus, Convergence,Nystagmus, Dissociated,Nystagmus, Fatigable Positional,Nystagmus, Horizontal,Nystagmus, Jerk,Nystagmus, Multidirectional,Nystagmus, Non-Fatigable Positional,Nystagmus, Pendular,Nystagmus, Periodic Alternating,Nystagmus, Permanent,Nystagmus, Rebound,Nystagmus, Retraction,Nystagmus, Rotary,Nystagmus, Rotational,Nystagmus, See-Saw,Nystagmus, Spontaneous Ocular,Nystagmus, Symptomatic,Nystagmus, Temporary,Nystagmus, Unidirectional,Nystagmus, Vertical,Ocular Nystagmus, Spontaneous,Pathologic Nystagmus,Positional Nystagmus, Non-Fatigable,See Saw Nystagmus
D002150	Caloric Tests	Elicitation of a rotatory nystagmus by stimulating the semicircular canals with water or air which is above or below body temperature. In warm caloric stimulation a rotatory nystagmus is developed toward the side of the stimulated ear; in cold, away from the stimulated side. Absence of nystagmus indicates the labyrinth is not functioning.	Barany Test,Barany's Test,Baranys Test,Caloric Test,Test, Barany,Test, Barany's,Test, Caloric,Tests, Caloric
D004584	Electronystagmography	Recording of nystagmus based on changes in the electrical field surrounding the eye produced by the difference in potential between the cornea and the retina.	Electronystagmographies
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014717	Vertigo	An illusion of movement, either of the external world revolving around the individual or of the individual revolving in space. Vertigo may be associated with disorders of the inner ear (EAR, INNER); VESTIBULAR NERVE; BRAINSTEM; or CEREBRAL CORTEX. Lesions in the TEMPORAL LOBE and PARIETAL LOBE may be associated with FOCAL SEIZURES that may feature vertigo as an ictal manifestation. (From Adams et al., Principles of Neurology, 6th ed, pp300-1)	CNS Origin Vertigo,Central Nervous System Origin Vertigo,Positional Vertigo,Spinning Sensation,Vertigo, Brain Stem,Vertigo, Brainstem,Vertigo, Central Nervous System Origin,Vertigo, Central Origin,Vertigo, Constant,Vertigo, Essential,Vertigo, Intermittant,Vertigo, Paroxysmal,Vertigo, Peripheral,Vertigo, Subjective,Brain Stem Vertigo,Brain Stem Vertigos,Brainstem Vertigo,Brainstem Vertigos,CNS Origin Vertigos,Central Origin Vertigo,Central Origin Vertigos,Constant Vertigo,Constant Vertigos,Essential Vertigo,Essential Vertigos,Intermittant Vertigo,Intermittant Vertigos,Origin Vertigo, CNS,Origin Vertigo, Central,Origin Vertigos, CNS,Origin Vertigos, Central,Paroxysmal Vertigo,Paroxysmal Vertigos,Peripheral Vertigo,Peripheral Vertigos,Sensation, Spinning,Sensations, Spinning,Spinning Sensations,Subjective Vertigo,Subjective Vertigos,Vertigo, CNS Origin,Vertigo, Positional,Vertigos,Vertigos, Brain Stem,Vertigos, Brainstem,Vertigos, CNS Origin,Vertigos, Central Origin,Vertigos, Constant,Vertigos, Essential,Vertigos, Intermittant,Vertigos, Paroxysmal,Vertigos, Peripheral,Vertigos, Subjective
D014724	Vestibular Function Tests	A number of tests used to determine if the brain or balance portion of the inner ear are causing dizziness.	Function Test, Vestibular,Function Tests, Vestibular,Test, Vestibular Function,Tests, Vestibular Function,Vestibular Function Test