Down-beat nystagmus is seen in lesion of ?

Ans. is 'b' i.e., Cerebellum Central vestibular nystagmus may be of following types ? Up-beat nystagmus In primary position of gaze, the fast component is upward. It is seen in lesions of central tegmentum of brain-stem. Down-beat nystagmus In primary position of gaze, the fast component is downward. It is usually associated with posterior fossa disease and is typical of compression at the level of foramen magnum. It is a common feature of cerebellar lesions and Arnold-chiary syndrome. Periodic alternative nystagms It is a jerk nystagmus which shows fluctuations in amplitude and direction. It may occur due to vascular or demyelinating vascular or brainstem-cerebellar lesions.