Nystagmus
Nystagmus is a rhythmic conjugated oscillating movement eyeballs. In nystagmus we describe:
- form (horizontal, vertical, diagonal),
- direction according to the fast (compensatory) component of nystagmus,
- degree (I–III),
- frequency (fast, slow),
- amplitude.
Degrees of nystagmus[edit | edit source]
- degree – when viewed in the direction of the fast component (nystagmus beats only to the side of the view);
- degree – nystagmus in direct view (right, left);
- degree – the least common, fast component against the direction of view.[1]
Vestibular nystagmus[edit | edit source]
Vestibular nystagmus is biphasic, has two components:
- component slow, tonic (vestibular, own pathological component, stronger apparatus pushes bulbs to the weaker)
- rapid, compensatory (cortical, we see it, to the side of the hyperfunctional labyrinth x deviation)
The direction is given by the fast folder.
- Horizontal – more frequent – beats right / left;
- vertical – top, bottom;
- rotatory;
- combination the above mentioned species (e.g. diagonal, alternating).[1]
Spontaneous nystagmus is always pathological (vestibular / vestibulocerebellar lesions). Under physiological circumstances, it is caused by a reflex effort to observe the object at such an angle that it is still projected into the macular area.[1]
Fixing nystagmus[edit | edit source]
It is physiological, occurs when the object is fixed in an extreme position by several eye twitches (in neurotics).[1]
Optokinetic nystagmus[edit | edit source]
In this case, it is a physiological phenomenon. It can typically be observed in persons travelling in means of transport (e.g. a moving train). In general, we invoke it by rapidly alternating images in the field of view. Incompetence leads to suspicion of cortical secondary occipital lesion.[1]
Congenital nystagmus[edit | edit source]
Congenital nystagmus occurs in some eye defects (severe refractive errors, amblyopia). It is often monophasic – pendulum.[1]
Nystagmus of miners[edit | edit source]
Miners nystagmus is accentuated during the transition from darkness to light.[1] This is a frequent phenomenon among miners in the 19th century.[2] It is probably also related to the toxic influence of gases (methane, carbon monoxide).
Bruns-Stewart dissociated nystagmus[edit | edit source]
This type of nystagmus arises from the pressure pathological process on brain stem (e.g. vestibular schwannoma); To the healthy side is gentle, regular, fast, on the side of the lesion rough, irregular, slow.[1]
Links[edit | edit source]
Related Articles[edit | edit source]
Ref[edit | edit source]
- ↑ a b c d e f g h SEIDL, Zdeněk – OBENBERGER, Jiří. Neurologie pro studium i praxi. 1. edition. Grada Publishing, 2004. ISBN 80-247-0623-7.
- ↑ BROWNE, R C – BECK, I F. Nystagmus in otherwise normal coal-miners. Br Med J [online]. 1954, vol. 1, no. 4872, p. 1176-9, Available from <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2085166/?tool=pubmed>. ISSN 0007-1447.
