How can I differentiate between vertigo and a stroke (cerebrovascular accident)?

Distinguishing Vertigo from Stroke: Clinical Approach

The most reliable way to distinguish vertigo from stroke is through the HINTS examination (Head Impulse, Nystagmus, Test of Skew), which when performed by trained practitioners is even more sensitive than early MRI for detecting stroke (100% versus 46%). 1

Key Differentiating Features

Clinical Presentation

• Peripheral Vertigo (Benign)

  • Positional symptoms that change with head movement
  • Brief episodes (seconds to minutes for BPPV)
  • Normal neurological examination
  • Positive Dix-Hallpike maneuver (for BPPV)
  • Horizontal nystagmus that diminishes with fixation

• Central Vertigo (Stroke)

  • Constant symptoms not changing with head movement
  • Sudden onset
  • Gait instability (9.3 times higher odds of stroke) 2
  • Subtle neurological findings (8.7 times higher odds of stroke) 2
  • Abnormal HINTS examination

The HINTS Examination

The HINTS examination consists of three components:

1. Head Impulse Test: Abnormal in peripheral vertigo (catch-up saccade present), normal in stroke
2. Nystagmus: Direction-changing in peripheral causes, direction-fixed in central causes
3. Test of Skew: Normal in peripheral vertigo, abnormal (vertical misalignment) in central causes

When performed by specially trained practitioners, the HINTS examination has been shown to be more sensitive than early MRI for detecting stroke. 3

VAIN Triad for Rapid Assessment

The VAIN triad (Vertigo-Ataxia, Incessant, or Non-positional) can help quickly identify potential central vertigo:

• V: Vertigo with unsteady gait/ataxia
• A: Ataxia (unsteady gait)
• I: Incessant (constant symptoms)
• N: Non-positional (no change with head movement)

The presence of any of these features has 100% sensitivity and 66.4% specificity for central vertigo. 4

Red Flags for Stroke

• Sudden severe headache with vertigo
• New neurological symptoms
• Inability to walk or stand
• Persistent vomiting with dizziness
• Altered mental status 1

Diagnostic Testing

• MRI Brain: Preferred imaging modality for suspected central vertigo
• CT Head: Often inadequate for diagnosing acute stroke in vertigo patients (missed all strokes in one study) 2
• High-Risk Patients: Consider MRI brain without contrast even with normal examination if patient has high vascular risk factors 1

Important Caveats

• Up to 25% of Acute Vestibular Syndrome cases may be due to stroke, and this can rise to 75% in high vascular risk cohorts 3
• One-third to two-thirds of patients with posterior circulation stroke may lack focal neurologic signs 3
• Small infarcts in the cerebellum or brainstem can present with vertigo without other localizing symptoms 5
• The TriAGe+ score can help identify stroke risk in patients with vertigo (sensitivity 96.6% at cutoff of 5 points) 6

Practical Approach

1. Perform the HINTS examination if trained
2. Check for VAIN triad features
3. Assess for subtle neurological findings
4. Consider MRI brain for:
   • Abnormal HINTS examination
   • Presence of VAIN triad features
   • Neurological deficits
   • High vascular risk patients

Remember that CT imaging is often inadequate for diagnosing stroke in vertigo patients, and MRI is the preferred modality when central causes are suspected.