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

Evaluation of Dizziness

Focus your evaluation on timing and triggers rather than the patient's vague description of "spinning" or "lightheadedness," as this approach categorizes patients into specific vestibular syndromes that guide diagnosis and management. 1, 2

Initial Categorization by Timing and Triggers

The American Academy of Otolaryngology-Head and Neck Surgery recommends classifying dizziness into four distinct vestibular syndromes based on temporal patterns 1, 2:

• Brief episodic vertigo (seconds to minutes) triggered by head movements suggests benign paroxysmal positional vertigo (BPPV) 1
• Acute persistent vertigo (days to weeks) with constant symptoms represents acute vestibular syndrome, which carries the highest stroke risk and requires differentiation between vestibular neuritis and posterior circulation stroke 1, 3
• Spontaneous episodic vertigo (minutes to hours) without triggers may indicate vestibular migraine or Ménière's disease 1
• Chronic vestibular syndrome (persistent symptoms >3 weeks) requires evaluation for central or systemic causes 1

Critical History Elements

Determine the exact duration, onset pattern, and specific triggers rather than accepting vague descriptions. 1, 2

• Positional triggers (rolling over in bed, looking up) strongly suggest BPPV 2
• Associated headache, photophobia, and phonophobia indicate vestibular migraine 1
• Hearing loss, tinnitus, or aural fullness suggest Ménière's disease 1, 2
• Neurological symptoms (diplopia, dysarthria, numbness, weakness) raise concern for central causes 2, 3

Physical Examination

Essential Bedside Tests

Perform the Dix-Hallpike maneuver for all patients with triggered episodic symptoms, as this provides more diagnostic value than imaging in most cases. 2, 3

• Observe for spontaneous nystagmus in all patients 2
• Execute Dix-Hallpike maneuver and supine roll test for suspected BPPV 1, 2
• Measure orthostatic vital signs to identify orthostatic intolerance 2

HINTS Examination for Acute Vestibular Syndrome

The HINTS examination (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). 1

However, when performed by non-experts, HINTS results are less reliable 1. Key findings:

• Normal head impulse test in acute vertigo with nystagmus suggests central cause 3
• Downbeating nystagmus or other central nystagmus patterns indicate brainstem or cerebellar pathology 3
• Abnormal test of skew (vertical misalignment) suggests central pathology 1

Red Flags Requiring Urgent Evaluation

A critical pitfall: 75-80% of patients with acute vestibular syndrome from posterior circulation infarction have no focal neurologic deficits on standard examination. 3

Immediate imaging and neurologic consultation are mandatory for 1, 3:

• Focal neurological deficits (diplopia, dysarthria, facial numbness, limb weakness, sensory changes)
• New severe headache accompanying dizziness
• Sudden unilateral hearing loss with vertigo
• Inability to stand or walk independently
• Downbeating nystagmus or central nystagmus patterns
• Unilateral or pulsatile tinnitus
• Loss of consciousness (never occurs with peripheral vestibular disorders)
• Failure to respond to appropriate vestibular treatments

Imaging Decisions

No imaging is indicated for brief episodic vertigo with typical BPPV features or acute persistent vertigo with normal neurologic exam and HINTS consistent with peripheral vertigo by a trained examiner. 1

When to Order MRI

MRI head without contrast is recommended for 1:

• Acute persistent vertigo with abnormal neurologic examination
• HINTS examination suggesting central cause
• High vascular risk patients with acute vestibular syndrome
• Unilateral tinnitus, pulsatile tinnitus, or asymmetric hearing loss
• Atypical presentation or red flags

CT Limitations

Do not assume CT head is adequate for stroke evaluation—CT misses many posterior circulation infarcts with sensitivity of only 20-40% for causative pathology in dizziness, whereas MRI with diffusion-weighted imaging is the appropriate study. 3

CT head without contrast may be appropriate before MRI in acute settings when stroke is suspected, but has low detection rate in isolated dizziness 1, 3.

Laboratory Testing

Routine laboratory testing has extremely low yield in patients with dizziness who have returned to baseline neurologic status. 2

Laboratory studies are not routinely indicated but may be considered when 2:

• History and physical examination suggest specific metabolic abnormalities
• Orthostatic symptoms suggest volume depletion or electrolyte disturbances
• Associated symptoms suggest systemic illness

Treatment Based on Diagnosis

BPPV

Canalith repositioning procedures (Epley maneuver) are first-line treatment for BPPV, and no imaging or medication is needed for typical cases. 1, 4

Ménière's Disease

Manage with salt restriction, diuretics, and in some cases, intratympanic treatments 1, 4.

Vestibular Migraine

Treat with migraine prophylaxis and lifestyle modifications 1.

Vestibular Neuritis

Symptoms are relieved with vestibular suppressant medications and vestibular rehabilitation 4.

Common Pitfalls to Avoid

• Do not rely on patient's description of "spinning" versus "lightheadedness"—elderly patients may not manifest classic "spinning" vertigo even with serious pathology. 1, 3
• Do not order routine imaging for isolated dizziness with typical peripheral features—the diagnostic yield is extremely low and most findings are incidental. 1, 3
• Do not assume a normal neurologic exam excludes stroke, as most posterior circulation strokes present without focal deficits. 1, 3
• Do not miss the opportunity to perform bedside testing—the Dix-Hallpike maneuver and HINTS examination provide more diagnostic value than imaging in most cases. 3