Introduction
What HINTS is, when to use it, and why a three-step bedside exam can out-perform early MRI for posterior circulation stroke.
Audio narrationchecking…
Introduction — The acute vestibular syndrome and the case for HINTS
- The acute vestibular syndrome is the sudden, persistent onset of vertigo lasting hours to days, with nystagmus, head-motion intolerance, nausea, vomiting, and unsteadiness of gait.
- It is one of the most common presentations of posterior circulation stroke — and one of the most commonly missed.
- The clinical question at the bedside is sharp and binary: is this patient's acute vertigo peripheral or central?
- HINTS is a three-step oculomotor exam — Head Impulse, Nystagmus, and Test of Skew — that, in trained hands, has been reported to be more sensitive for stroke than early MRI in the first 24 to 48 hours of symptom onset.
- The protocol relies on features that are immediately observable at the bedside. It requires no equipment and takes under two minutes to complete.
- HINTS was developed and validated for patients with continuous acute vestibular syndrome. It is not appropriate for episodic positional vertigo — use Dix-Hallpike for that — or for patients without nystagmus at the time of examination.
- The validation studies were performed by neuro-otologists with subspecialty expertise. Reported sensitivity and specificity in less experienced hands are substantially lower.
- The strongest evidence supports HINTS-plus — the original three plus assessment for new auditory symptoms — interpreted by trained clinicians.
The acute vestibular syndrome
The acute vestibular syndrome (AVS) is the sudden, persistent onset of vertigo lasting hours to days, with nystagmus, head-motion intolerance, nausea, vomiting, and unsteadiness of gait. It is one of the most common presentations of posterior circulation stroke — and one of the most commonly missed.
The clinical question at the bedside is sharp and binary: is this patient's acute vertigo peripheral (vestibular neuritis, labyrinthitis) or central (cerebellar or brainstem stroke)?
Why HINTS
HINTS is a three-step oculomotor exam — Head Impulse, Nystagmus, Test of Skew — that, in trained hands, has been reported to be more sensitive for stroke than early MRI with diffusion-weighted imaging within the first 24–48 hours of symptom onset3. The protocol relies on features that are immediately observable at the bedside, requires no equipment, and takes under two minutes to complete.
When HINTS applies — and when it does not
HINTS was developed and validated for patients with the continuousacute vestibular syndrome. It is not appropriate for episodic positional vertigo (use Dix-Hallpike), for vertigo of less than several hours' duration, for patients without nystagmus at the time of examination, or for patients with normal head impulse and no spontaneous nystagmus — they are likely outside the protocol's validated domain.
Operator dependency
The validation studies were performed by neuro-otologists with subspecialty expertise3. Reported sensitivity and specificity in less experienced hands are substantially lower. Video head impulse testing (vHIT) reduces operator dependency for the impulse component but is not always available at the bedside8. The strongest evidence supports HINTS-plus — the original three plus assessment for new auditory symptoms — interpreted by trained clinicians10,1.
How this atlas is organised
The first four modules cover anatomy and physiology of the vestibulo-ocular reflex, examination technique, and what normal findings look like. The disease modules then walk through the HINTS signature of each major cause of AVS. Tools — comparison, trainer, cases, quiz, glossary, references — let you practise pattern recognition and check your understanding.