Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0028738 (nystagmus)
 7,431 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Observation of nystagmus is of great importance in the otoneurologic examination. By means of electronystagmography it is possible to examine the nystagmus under different visual conditions such as in darkness or with eyes closed. Physiological nystagmus is characterized by miniature eye movements with an amplitude of 4-5 minutes of one degree. With fixation, the amplitude decreases and the frequency increases. Vestibular nystagmus is a biphasic eye movement with slow and rapid phases of opposite directions. The intensity increases when the eye bulb is directed in the same direction as the fast phase or when fixation is hampered by darkness or eye closure. Nystagmus in which the fast phase changes direction according to the direction of gaze, i.e. gaze (paretic) nystagmus, can be congenital, but is often a result of paralysis of the eye muscles, of infection, intoxication or, if asymmetric in amplitude, of an acoustic neurinoma. Fixation nystagmus, miner's nystagmus, and nystagmus latens, is called optic nystagmus, and is thought to be caused by defects in the fixation mechanism. The main characteristic is that it changes direction if one or both eyes are closed and often interferes with the vestibular nystagmus. In the diagnosis of dizzy patients with optic nystagmus, the examination of the vestibular system must be carried out with other methods than nystagmus recordings.
 ...
PMID:Vestibular and non-vestibular nystagmus in examination of dizzy patients. 326 57

Fixation nystagmus suppression in caloric tests was used in examination of 56 patients suffering from chronic remittent labyrinthopathy, acute labyrinthopathy, vestibular neuronitis, otosclerosis, adhesive otitis media, vertebrobasilar insufficiency, motor disease, chronic remittent vestibulopathy and neurinoma of the VIII nerve. The bithermal test (BT) with electronystagmography was made to calculate the fixation suppression index (FSI). Complete suppression of the caloric nystagmus in at least one BT test appeared to be the most frequent variant of the response (24 cases). This was not dependent on the severity of the vestibular analyzer lesion. In 3 cases FSI of the caloric nystagmus was rather high (> 0.50). Introduction of the period of glance fixation in performance of all the 4 BT tests may serve an additional method in differential diagnosis of the vestibular disorders. The fixation test results should be compared to findings obtained in the other vestibulometric tests.
 ...
PMID:[The phenomenon of the fixation suppression of caloric nystagmus in the diagnosis of vestibular disorders]. 975 93