What is the approach to evaluate dizziness?

Evaluation of Dizziness

Focus your evaluation on timing and triggers rather than the patient's subjective description of symptoms to categorize dizziness into one of four vestibular syndromes, which will guide all subsequent diagnostic and management decisions. 1, 2

Initial History: Critical Elements

The most diagnostically valuable information comes from specific timing patterns and triggers, not vague patient descriptions like "spinning" versus "lightheadedness" 1, 2, 3:

Categorize by Timing Pattern

• Acute Vestibular Syndrome (AVS): Continuous dizziness lasting days to weeks 1, 2
• Triggered Episodic: Seconds to minutes of vertigo provoked by head movements (suggests BPPV) 2, 3
• Spontaneous Episodic: Recurrent episodes lasting 20 minutes to 12 hours without positional triggers (suggests Ménière's disease or vestibular migraine) 2, 3
• Chronic Vestibular Syndrome: Persistent symptoms for months 2

Essential Associated Symptoms

• Hearing loss, tinnitus, or aural fullness suggest Ménière's disease 1, 2, 3
• Headache with photophobia and phonophobia suggest vestibular migraine 2
• Neurological symptoms (diplopia, dysarthria, facial numbness, limb weakness) mandate urgent evaluation for posterior circulation stroke 1, 3

Medication Review

• Review antihypertensives, sedatives, anticonvulsants, and psychotropic drugs—these are leading causes of chronic dizziness 2

Physical Examination: Targeted Maneuvers

Observe for Spontaneous Nystagmus

• Check all patients with dizziness for spontaneous nystagmus at rest 1
• Downbeating nystagmus or other central patterns are red flags requiring urgent evaluation 2, 3

Positional Testing for BPPV

• Perform Dix-Hallpike maneuver for suspected BPPV (brief positional vertigo <1 minute) 1, 2
• Positive test shows latency of 5-20 seconds, transient upbeating-torsional nystagmus toward affected ear, and symptoms that resolve within 60 seconds 2
• Perform supine roll test to assess horizontal canal BPPV 1

HINTS Examination for Acute Vestibular Syndrome

• HINTS (Head Impulse, Nystagmus, Test of Skew) is more sensitive than early MRI for detecting posterior circulation stroke when performed by trained practitioners (100% vs 46% sensitivity) 2
• A critical caveat: 75-80% of patients with posterior circulation stroke have NO focal neurologic deficits on standard exam—do not assume normal neurologic exam excludes stroke 2, 3
• When performed by non-experts, HINTS reliability decreases significantly 2

Orthostatic Blood Pressure

• Measure orthostatic vital signs to assess for postural hypotension 3

Imaging: When and What to Order

Do NOT Order Imaging For:

• Brief episodic vertigo with typical BPPV features and positive Dix-Hallpike test 2
• Acute persistent vertigo with normal neurologic exam and HINTS consistent with peripheral vertigo by trained examiner 2
• Straightforward BPPV cases—imaging is unnecessary and delays treatment 2

Order MRI Brain Without Contrast For:

• Acute persistent vertigo with abnormal neurologic examination 2
• HINTS examination suggesting central cause 2
• High vascular risk patients with acute vestibular syndrome 2
• Unilateral tinnitus, pulsatile tinnitus, or asymmetric hearing loss 2
• Progressive symptoms suggesting mass lesion 2

Critical Imaging Pitfall:

• CT head has very low diagnostic yield (<1%) for isolated dizziness and only 20-40% sensitivity for posterior circulation infarcts—do not use CT instead of MRI when stroke is suspected 2, 3
• MRI with diffusion-weighted imaging has significantly higher diagnostic yield (4% in isolated dizziness, up to 16% when changing diagnosis) 2

Diagnostic Testing

Audiometric Testing

• Obtain comprehensive audiologic examination for patients with unilateral tinnitus, persistent symptoms, or associated hearing difficulties 2
• Ménière's disease requires clinical diagnosis based on patient symptoms and audiometric data—not vestibular function testing 4

Vestibular Function Testing

• Do NOT routinely order vestibular function testing (VNG, caloric testing, rotary chair, vHIT, VEMP) or ECochG to diagnose Ménière's disease—these tests fluctuate throughout disease course and correlate poorly with patient disability 4
• Vestibular testing may be appropriate only if clinical presentation is atypical, Dix-Hallpike findings are equivocal, or additional symptoms suggest concurrent CNS or otologic disorders 2
• Unnecessary vestibular testing contributes to delays in diagnosis, increased costs, and patient morbidity 4

Red Flags Requiring Urgent Evaluation

Any of these findings mandate immediate imaging and neurologic consultation 2, 3:

• Focal neurological deficits (diplopia, dysarthria, facial numbness, limb weakness)
• Sudden unilateral hearing loss with vertigo
• Inability to stand or walk independently
• New severe headache accompanying dizziness
• Downbeating nystagmus or other central nystagmus patterns
• Failure to respond to appropriate vestibular treatments

Common Diagnostic Pitfalls to Avoid

• Do not rely on patient descriptions of "spinning" versus "lightheadedness"—focus exclusively on timing and triggers 2, 3
• Do not assume normal neurologic exam excludes stroke—most posterior circulation infarcts present without focal deficits 2, 3
• Do not order routine imaging for isolated dizziness—most findings are incidental with low diagnostic yield 2
• Do not order comprehensive vestibular testing for straightforward BPPV—it is unnecessary and delays treatment 2
• Do not use CT when stroke is suspected—CT misses many posterior circulation infarcts 2