Which test elicits nystagmus by moving the visual scene around the patient?

• A. Vestibular-evoked myogenic potentials
• B. Caloric testing
• C. Optokinetic testing
• D. Oculocephalic testing

Answer: (C)

Optokinetic testing provokes eye movements by moving the visual scene, triggering optokinetic nystagmus. When the patient watches a moving field (such as striped drums or a video), the eyes first slowly follow the moving scene and then make quick corrective saccades in the opposite direction, producing the characteristic nystagmus of the optokinetic reflex. This method specifically harnesses the visual motion system to elicit nystagmus, unlike caloric testing (which uses thermal stimulation of the inner ear), VEMP (a muscular reflex from otolith organs), or oculocephalic testing (eye movements driven by head rotation).