What is the approach to evaluating a patient presenting with dizziness?

Evaluation of Dizziness

Initial Diagnostic Framework

Categorize dizziness by timing and triggers rather than symptom quality (e.g., "spinning" vs "lightheadedness"), as this approach directly guides physical examination and distinguishes benign peripheral vestibular disorders from dangerous central causes like stroke 1, 2.

Classify patients into one of three vestibular syndromes 1:

1. Triggered Episodic Vestibular Syndrome (Seconds to <1 minute)

• Brief episodes triggered by head position changes strongly suggest BPPV 3, 1
• Perform the Dix-Hallpike maneuver immediately—this is the gold standard diagnostic test 3, 2
• Positive findings include: 5-20 second latency period, torsional upbeating nystagmus toward the affected ear, symptoms resolving within 60 seconds 3, 2
• Critical pitfall: Skipping the Dix-Hallpike delays diagnosis and treatment unnecessarily 3

2. Acute Vestibular Syndrome (Days to weeks, constant symptoms)

• Perform HINTS examination (Head Impulse, Nystagmus, Test of Skew) to distinguish peripheral from central causes 1, 2
• HINTS has 100% sensitivity for posterior circulation stroke when performed by trained practitioners—superior to early MRI (46% sensitivity) 1, 2
• Critical pitfall: 75-80% of posterior circulation strokes have NO focal neurologic deficits, so a normal neurologic exam does NOT exclude stroke 3, 2
• If HINTS suggests central pathology or examiner is not trained in HINTS, proceed directly to MRI brain without contrast 1, 2

3. Spontaneous Episodic Vestibular Syndrome (Minutes to hours, no positional trigger)

• Associated symptoms guide diagnosis 1:
  • Hearing loss, tinnitus, aural fullness → Ménière disease 3, 1
  • Headache, photophobia, phonophobia → vestibular migraine 3, 1, 2

Essential Physical Examination Components

Perform a complete neurologic examination including 3, 1:

• Cranial nerve testing 3, 1
• Cerebellar testing (finger-to-nose, heel-to-shin, rapid alternating movements) 3, 1
• Gait assessment 3, 1
• Observation for spontaneous nystagmus, particularly central patterns (downbeating, direction-changing) 3, 1
• Orthostatic vital signs 4

Imaging Decision Algorithm

No imaging indicated for 1, 2:

• Brief episodic vertigo with typical BPPV features and positive Dix-Hallpike 1, 2
• Acute persistent vertigo with normal neurologic exam AND HINTS consistent with peripheral vertigo by trained examiner 1, 2

MRI brain without contrast is indicated for 1, 2:

• Abnormal neurologic examination 1, 2
• HINTS examination suggesting central cause 1, 2
• High vascular risk patients with acute vestibular syndrome 1, 2
• Unilateral or pulsatile tinnitus 1, 2
• Asymmetric hearing loss 1, 2
• Focal neurological deficits 3, 2
• Sudden unilateral hearing loss 3
• Inability to stand or walk 3, 2
• Downbeating or other central nystagmus patterns 3, 2
• New severe headache 2
• Progressive neurologic symptoms 3

CT head has extremely limited utility 1, 2:

• Diagnostic yield <1% for isolated dizziness 1, 2
• Sensitivity only 20-40% for posterior circulation infarcts 2
• Should NOT be used instead of MRI when stroke is suspected 3, 2

Laboratory Testing

Routine laboratory testing has extremely low yield in patients with isolated dizziness and normal examination 3:

• Consider bedside glucose testing in specific situations 3
• Consider pregnancy testing when appropriate 3

Treatment Based on Diagnosis

BPPV

Perform canalith repositioning procedure (Epley maneuver) immediately—success rate 90-98% 3, 1, 2:

• No medications needed 3, 2
• Counsel patients about 10-18% recurrence rate at 1 year 3
• Critical pitfall: Ordering imaging for straightforward BPPV delays treatment unnecessarily 3

Vestibular Migraine

• Migraine prophylaxis and lifestyle modifications 3, 1, 2

Ménière Disease

• Salt restriction and diuretics 1, 2
• Intratympanic dexamethasone or gentamicin for refractory cases 1, 2

Posterior Circulation Stroke

• Activate stroke protocol immediately 1
• Urgent neurology consultation 1

Critical Pitfalls to Avoid

• Do not rely on patient's description of "spinning" vs "lightheadedness"—focus on timing and triggers instead 1, 2
• Do not assume normal neurologic exam excludes stroke—most posterior circulation strokes lack focal deficits 3, 2
• Do not skip the Dix-Hallpike maneuver when BPPV is suspected 3
• Do not order imaging for straightforward BPPV without red flags 3
• Do not use CT when stroke is suspected—use MRI 3, 2
• Do not rely on HINTS examination results from non-expert examiners 2