What are the key history clues and physical examination findings for evaluating vertigo?

HINTS Plus Examination for Vertigo

The HINTS (Head Impulse, Nystagmus, Test of Skew) examination is a three-step bedside test that achieves 92.9% sensitivity and 83.4% specificity for detecting stroke in patients with acute vestibular syndrome when performed by trained clinicians, making it more sensitive than early MRI (100% vs 46%). 1

What is HINTS?

HINTS is specifically designed for acute vestibular syndrome (AVS)—continuous vertigo lasting days with nausea, vomiting, and head-motion intolerance—not for brief positional vertigo like BPPV. 2, 3

The Three Components:

1. Head Impulse Test (HIT)

• Rapidly rotate the patient's head 10-20° to each side while they fixate on your nose 1
• Normal (central/stroke): Eyes remain fixed on target—this is ABNORMAL and suggests stroke 1
• Abnormal (peripheral): Eyes make a corrective saccade back to target—this is reassuring for peripheral cause 1
• Sensitivity 76.8%, specificity 89.1% for central causes 1

2. Nystagmus Assessment

• Observe spontaneous nystagmus in primary gaze and with lateral gaze 3
• Central patterns (red flags): 2, 3
  • Pure vertical (up or down) without torsional component
  • Direction-changing without head position changes
  • Direction-switching with gaze (beats right on right gaze, left on left gaze)
  • Not suppressed by visual fixation
  • Does not fatigue with repeated testing
• Peripheral patterns (reassuring): 3
  • Horizontal with rotatory component
  • Unidirectional
  • Suppressed by visual fixation
  • Fatigable

3. Test of Skew

• Perform alternate cover test while patient fixates on your nose 1
• Abnormal (central): Vertical misalignment when covering/uncovering each eye 1
• Normal (peripheral): No vertical deviation 1
• Sensitivity 23.7%, specificity 97.6% for central causes 1

HINTS Plus (Adding Hearing)

HINTS Plus adds acute hearing loss assessment to the standard HINTS examination, achieving 99.0% sensitivity and 84.8% specificity for stroke. 1

• New hearing loss + central HINTS findings: Suggests anterior inferior cerebellar artery (AICA) stroke 1
• Hearing loss + peripheral HINTS findings: Suggests labyrinthitis (benign) 4

Critical Interpretation Rules

A HINTS examination is "central" (concerning for stroke) if ANY ONE of the following is present: 3, 1

• Normal head impulse test (no corrective saccade)
• Central nystagmus pattern (vertical, direction-changing, or gaze-evoked)
• Positive skew deviation

All three components must be "peripheral" to rule out stroke. 1

When to Use HINTS vs Dix-Hallpike

Use HINTS for:

• Acute vestibular syndrome: Continuous vertigo lasting hours to days 2, 3
• Severe nausea/vomiting with head-motion intolerance 3
• Suspected vestibular neuritis vs stroke 4

Use Dix-Hallpike for:

• Triggered episodic vestibular syndrome: Brief episodes (<1 minute) triggered by position changes 2, 3
• Suspected BPPV 2

Key History Clues for Vertigo Evaluation

Focus on timing and triggers, not descriptive terms like "dizzy" or "lightheaded," which are unreliable. 3, 5

Four Vestibular Syndrome Categories: 3

1. Acute Vestibular Syndrome (AVS):

   • Continuous vertigo lasting days to weeks 3
   • Includes vestibular neuritis, labyrinthitis, stroke 3
   • 25% have stroke, rising to 75% in high vascular risk patients 2, 6

2. Triggered Episodic Vestibular Syndrome:

   • Brief episodes (<1 minute) with specific position triggers 3
   • BPPV is most common (42% of vertigo cases) 3, 6

3. Spontaneous Episodic Vestibular Syndrome:

   • Episodes lasting minutes to hours without triggers 3
   • Includes vestibular migraine (14% of cases), Ménière's disease 2, 3

4. Chronic Vestibular Syndrome:

   • Persistent symptoms lasting weeks to months 3
   • Includes medication effects, anxiety, posterior fossa masses 3

Red Flags Requiring Immediate MRI

Any of the following demand urgent diffusion-weighted MRI: 3

• Severe postural instability with falling 2, 3
• New-onset severe headache with vertigo 3
• Any focal neurologic symptoms (dysarthria, dysphagia, diplopia, weakness, numbness, Horner's syndrome) 2
• Downbeating nystagmus on Dix-Hallpike without torsional component 2, 3
• Baseline nystagmus without provocative maneuvers 2, 3
• Failure to respond to appropriate peripheral vertigo treatment 2, 3

Common Pitfalls

• 75-80% of stroke patients with AVS have NO focal neurologic deficits—absence of weakness or dysarthria does not exclude stroke 2, 6
• 10% of cerebellar strokes mimic peripheral vestibular disorders 2, 6
• HINTS performed by non-experts has mixed accuracy—refer if uncertain 2
• Do not use HINTS for brief positional vertigo—it is designed only for continuous AVS 2, 3
• Isolated transient vertigo may precede vertebrobasilar stroke by weeks to months 2, 3