Which type of nystagmus is most characteristic of central vertigo?

• A. Pure horizontal nystagmus
• B. Pure vertical (upbeat or downbeat) or direction-changing nystagmus
• C. Nystagmus that fatigues with repetition of testing
• D. Gaze-evoked horizontal nystagmus

Answer: (B)

Central vertigo often disrupts the brainstem and cerebellar circuits that control eye gaze, so the nystagmus you see is typically vertical (upbeat or downbeat) or it changes direction with where the patient is looking. Vertical nystagmus is especially a red flag for central involvement because, in most peripheral causes, nystagmus is horizontal and stays the same with gaze. A nystagmus that reverses direction when the patient shifts gaze reflects a faulty gaze-holding mechanism in the brainstem/cerebellum, another hallmark of central pathology. So the best giveaway is seeing vertical or direction-changing nystagmus, rather than a simple horizontal, fixed nystagmus.