Nystagmus

Nystagmus is an involuntary, repetitive movement of the eyes. It can be horizontal, vertical, or rotary in direction, and it can occur spontaneously, in response to specific head positions, or during caloric testing of the vestibular system. In vestibular medicine and audiology, nystagmus is significant because it is often a sign of vestibular system dysfunction.

The inner ear's vestibular organs have strong neural connections to the eye muscles. Disruption to vestibular input can trigger involuntary eye movements as the brain tries to compensate for conflicting signals. Nystagmus is commonly observed in benign paroxysmal positional vertigo (BPPV), vestibular neuritis, Meniere's disease, and other balance disorders. During vestibular testing, a clinician records nystagmus using video goggles (videonystagmography, or VNG) to analyze the eye movement patterns.

Nystagmus can also have central causes (originating in the brainstem or cerebellum) that require neurological investigation.