Introduction
Look at the eyes.
Most dizziness is peripheral and benign. A minority is central and dangerous — and the eyes give it away. This chapter is an atlas of the ocular-motor signs of vertigo and what they localise.
- 0%of acute vestibular syndromes are strokes — not neuritisTarnutzer 2011 · Kim & Lee 2012
- 0%of posterior-fossa strokes are missed by early DWI-MRIKattah 2009 · Saber Tehrani 2014
- 0%stroke detection by a central HINTS pattern in expert handsKattah 2009 (Stroke)
- 0%lifetime prevalence of vertigo in the general populationNeuhauser 2007
The inner ear and the eyes are wired together. Every head movement triggers a reflexive eye movement that keeps the world still on the retina — the vestibulo-ocular reflex. When that system is upset, the eyes betray the cause before any scan does.
Look for unprovoked jerking of the eyes (nystagmus), eyes that don't move together properly on lateral gaze (internuclear ophthalmoplegia), or eyes that sit at different heights (skew deviation). These signs separate harmless inner-ear trouble from brainstem or cerebellar disease.
Around 30% of the population experience vertigo in their lifetime,1and roughly a quarter of patients presenting with acute vestibular syndrome (AVS) have a posterior-circulation stroke — not vestibular neuritis.3,5Early diffusion-weighted MRI can be falsely negative for small posterior-fossa infarcts in the first 24–48 hours, and a careful ocular-motor exam is more sensitive in that window.2,4
The chapter is organised around the signs themselves: nystagmus and its patterns, ocular misalignment (INO, skew, OTR), saccades and pursuit, and oscillopsia and diplopia — closing with the HINTS bedside exam in acute vertigo and the disease vignettes where these signs are characteristic.
The clinical edge is recognising that a normal head impulse test in a patient with ongoing AVS is paradoxical — it points to a brainstem or cerebellar lesion with the peripheral VOR pathway intact, and the HINTS triad (normal HIT, direction-changing nystagmus, skew on alternate cover) outperforms early MRI for posterior-circulation stroke.2
Every section pairs the underlying anatomy with what to do at the bedside. The chapter closes with a Sign Explorer that filters the catalogue by origin, urgency, and free text, and a self-assessment that tests the bedside calls that matter most.