All of them are true about Optokinetic Nystagmus (OKN) EXCEPT
Optokinetic nystagmus It is a physiological jerk nystagmus ( not pathological) Useful in localizing cause of an isolated homonymous hemianopia. Induced by presenting to gaze the objects moving serially in one direction, such as strips of a spinning optokinetic drum. The eyes will follow a fixed strip momentarily and then jerk back to reposition centrally to fix up a new strip. Similar condition occurs while looking at outside things from a moving train. note- - Saccade are Rapid jerky conjugate eye movements,to direct the fovea to a target as the gaze shifts from one object to another Contralateral frontal lobe initiates it & Flocculus(Lobule IX of cerebellum) controls it. - Pursuit is slow tracking eye movements to direct target on fovea.Ipsilateral parieto-occipital lobe controls it & Fastigial nuclei initiates it
Jerk nystagmus induced by moving repetitive targets
Useful for localising cause of isolated homonymous hemianopia
Slow phase is a pursuit, fast phase is saccade
Type of pathological nystagmus
Neuro Ophthalmology