True about central nystagmus -

Ans. is 'd' i.e., All of the aboveNystagmuso Nystagmus is a rhythmic oscillatory movement of the eye.o Nystagmus has the following characteristics:-i) Rapid,ii)Involuntary,iii) Repetitiveo Nystagmus may be 0 Side to side (horizontal nystagmus)Up and down (verticle nystagmus)Rotaryo Vestibular nystagmus has two components, i.e. a slow and a fast.o The direction of nystagmus is indicated by the direction of the fast component.o Vestibular nystagmus may be:- Peripheral:-due to a lesion of labyrinth or VIII nerve.Centraldue :-to lesion of vestibular nuclei, brainstem or cerebellum.Peripheral nystagmusDiminishes or suppresses with gaze fixation (optic fixation)Enhances in darkness or by use of Frenzel glassesUnidirectional fast componentThe direction is typically horizontal - rotary, not purely horizontal or rotary and not verticalThe direction is fixed towards the undermost earPresent in one head positionCentral nystagmusNot suppressed by optic fixationThe fast component can be unidirectional or bidirectional.Can be horizontal, vertical or rotary a Direction is changingPresent in multiple head positions