What is the approach to evaluate dizziness?

Evaluation of Dizziness

Begin by categorizing dizziness based on timing and triggers rather than the patient's subjective description, as this approach directly guides diagnosis and management. 1

Initial Categorization by Vestibular Syndrome

Classify dizziness into one of four vestibular syndromes based on temporal patterns 1:

• Acute Vestibular Syndrome (AVS): Acute persistent dizziness lasting days to weeks 1
• Triggered Episodic Vestibular Syndrome: Brief episodes provoked by specific movements or positions 1
• Spontaneous Episodic Vestibular Syndrome: Recurrent episodes without clear triggers 1
• Chronic Vestibular Syndrome: Persistent symptoms over months 1

Critical History Elements

Focus on these specific components rather than vague symptom descriptions 1:

• Duration and onset: Seconds (BPPV), minutes to hours (Ménière's), days (vestibular neuritis), or chronic 1, 2
• Positional triggers: Head movements, rolling in bed, looking up 1, 2
• Associated otologic symptoms: Hearing loss, tinnitus, or aural fullness suggest Ménière's disease 1, 3
• Neurological red flags: Headache, diplopia, dysarthria, numbness, weakness, or ataxia indicate potential central causes requiring urgent evaluation 1

Physical Examination Protocol

Observe for Spontaneous Nystagmus

Examine all patients for spontaneous nystagmus at rest 1, 2. The pattern helps differentiate peripheral from central causes 2.

Perform Dix-Hallpike Maneuver

For suspected BPPV (brief episodes triggered by position changes), perform the Dix-Hallpike maneuver 4, 1, 2:

• Positive test shows torsional, upbeating nystagmus with latency 2
• A positive Dix-Hallpike test is sufficient to diagnose BPPV and proceed with treatment without further testing 4

Supine Roll Test

Assess for horizontal canal BPPV 1

HINTS Examination (for AVS)

In patients with acute persistent dizziness, perform the HINTS examination (Head Impulse, Nystagmus, Test of Skew) to differentiate peripheral from central causes 1, 2:

• Central findings indicate stroke risk and require urgent imaging 1, 2

Imaging Decisions

Imaging is NOT routinely indicated for most dizziness cases 4, 1, 2. The positivity rate of head CT in emergency departments for dizziness is only 2% 4.

When to Image:

• Neurological symptoms or signs present: Focal deficits, ataxia, severe headache 4, 1
• HINTS examination suggests central cause: Requires urgent MRI 1, 2
• Atypical nystagmus patterns: Not consistent with peripheral vestibular disorders 2
• No improvement with appropriate treatment: Consider structural causes 2

Imaging Modality Selection:

• MRI brain with diffusion-weighted imaging: Preferred for suspected stroke (4% of isolated dizziness cases) 4, 1
• CT temporal bone: For suspected structural ear abnormalities 1
• CT head: Has very low yield; avoid in isolated dizziness without neurological findings 4

Do NOT Image:

• Typical BPPV with positive Dix-Hallpike test: Diagnosis is clinical 4, 2
• Clear peripheral vestibular syndrome without red flags: Imaging does not improve diagnostic accuracy 4

Vestibular Function Testing

Do NOT routinely order vestibular testing (VNG, caloric testing, rotary chair, vHIT, VEMP) or electrocochleography for diagnosis 4:

• BPPV diagnosis is based on history and Dix-Hallpike testing alone 4
• Ménière's disease remains a clinical diagnosis based on symptoms and audiometry 4
• Vestibular testing results fluctuate and correlate poorly with patient disability 4

Consider Vestibular Testing Only When:

• Atypical or equivocal nystagmus findings 4
• Multiple concurrent peripheral vestibular disorders suspected 4
• Additional vestibular symptoms inconsistent with the primary diagnosis 4

Common Pitfalls to Avoid

• Overuse of imaging in peripheral causes: Perform appropriate bedside tests (Dix-Hallpike, HINTS) before ordering imaging 1
• Missing stroke in isolated dizziness: Remember that 4% of isolated dizziness is due to stroke; use HINTS examination in AVS 1
• Ordering routine laboratory tests: These have low diagnostic yield in unselected patients 5
• Delaying treatment while awaiting unnecessary testing: BPPV can be treated immediately after positive Dix-Hallpike without imaging or vestibular testing 4
• Relying on patient's description of "vertigo" vs "dizziness": Focus on timing and triggers instead, as patient descriptions are often vague and inconsistent 1, 6