Summary:
Congenital nystagmus (CN) is a clinical syndrome
characterized by involuntary and rhythmical nystagmic eye
movements that are found most often during the first weeks of
life. The etiopathogenesis of congenital nystagmus has not been
clear so far. The disturbed detection of movement may be its
cause. In etiology, there are considered metabolic
abnormalities and structural anomalies of the CNS including
the affection of optic pathways. According to the form, congenital nystagmus is classified into basic categories by the shape of particular nystagmic jerks. The most
frequent are jerk forms presented by biphasic nystagmic jerk with a rapid and slow phase, and pendular
forms. In jerky nystagmus, an abnormal development of oculo-motor brain areas controlling mechanisms
of visual fixation are considered as its base. This type may display autosomal dominant, autosomal recessive
and/or X-linked heredity. The trial involved patients with congenital nystagmus examined at the ENT
Clinic, Faculty Hospital Královské Vinohrady, for vertigo, hearing disturbances and tinnitus within 2001 –
2004. Totally, twelve patients were examined. Detailed electromyographic or video-oculo-graphic
examinations are needed for differentiating individual forms of congenital nystagmus. In our set, a sensoric
defect or presence of ocular abnormality were observed in 4 cases, and the patients suffered from pendular
form of CN. The other patients – totally 8 – had motor CN, and 4 cases demonstrated pendular form, 4 cases
jerk form of CN. Relatively high occurrence (5 cases – 42%) of hearing defects and tinnitus in patients with
congenital nystagmus was very interesting. In some cases congenital nystagmus may present diagnostic
problems, particularly in the cases of CN coinciding with disturbances of equilibrium.
Key words:
nystagmus, congenital nystagmus, fixation nystagmus
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