Application

HINTS in acute vertigo

Acute vestibular syndrome — sudden, continuous vertigo for >24 hours — is usually neuritis. About a quarter of cases are strokes. The eyes settle the question before the scanner does.

The clinical problem

Trainee

Acute vestibular syndrome (AVS)is defined by acute onset, persistent vertigo or dizziness > 24 hours, nausea/vomiting, gait instability, and nystagmus. The differential is dominated by vestibular neuritis and posterior-circulation stroke. Around 1 in 4 AVS cases is a stroke.4,7

Crucially, diffusion-weighted MRI in the first 24–48 hours misses ~10–20% of small posterior-fossa infarcts;5 in this window the bedside HINTS battery is more sensitive than MRI for identifying central pathology.1

Run HINTS

Pick one option in each step — the verdict updates live. The central pattern (any one of: normal HIT, direction-changing nystagmus, or skew) is more sensitive than early DWI-MRI for posterior-circulation stroke.

1
Head Impulse
Rapidly turn the head ~15° to one side while the patient fixates a target.
2
Nystagmus
Observe in primary gaze and on left/right eccentric gaze.
3
Test of Skew
Alternate-cover test: look for a vertical refixation as each eye is uncovered.

Pick one option in each step to see the verdict.

Sensitivity for posterior-circulation stroke in AVS
  • HINTS-plus (HINTS + hearing screen)
    99%
    Newman-Toker 2013
  • HINTS (three-step bedside)
    100%
    Kattah 2009
  • Early DWI-MRI (<48 h)
    80%
    Saber Tehrani 2014
Bedside HINTS in trained hands outperforms early diffusion-weighted MRI for catching small posterior-fossa infarcts in the first 24–48 hours. HINTS-plus adds a finger-rub hearing screen to capture AICA-territory strokes presenting with sudden hearing loss.

Caveats and the INFARCT cue

HINTS is for AVS — not for episodic vertigo, not for chronic dizziness, and not for patients whose nystagmus has resolved. Apply only when the patient is symptomatic with nystagmus. The mnemonic INFARCT captures the central pattern: Impulse Normal, Fast-phase Alternating, Refixation on Cover Test. Any one of those features warrants imaging.