What is the initial approach to evaluating dizziness, including history, physical exam, and further evaluation?

Evaluation of Dizziness

Initial Diagnostic Framework

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

Classify patients into one of three vestibular syndromes based on temporal patterns 1, 3:

1. Acute Vestibular Syndrome (AVS)

• Continuous symptoms lasting days to weeks with acute onset 1, 2
• Perform HINTS examination (Head Impulse, Nystagmus, Test of Skew) - this 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 patients with posterior circulation stroke have NO focal neurologic deficits, so a normal neurologic exam does not exclude stroke 2

2. Triggered Episodic Vestibular Syndrome

• Brief episodes lasting seconds to <1 minute triggered by head movements 1, 2
• Perform Dix-Hallpike maneuver (gold standard for BPPV) looking for: 5-20 second latency, torsional upbeating nystagmus toward affected ear, symptoms that crescendo then resolve within 60 seconds 2, 3
• Perform supine roll test for horizontal canal BPPV 1, 3

3. Spontaneous Episodic Vestibular Syndrome

• Episodes lasting minutes to hours without positional triggers 1, 2
• Associated symptoms guide diagnosis: hearing loss/tinnitus/aural fullness → Ménière's disease; headache/photophobia/phonophobia → vestibular migraine 1, 2

Essential History Components

Focus on these specific details rather than vague descriptions 1, 2, 3:

• Duration: Seconds (BPPV), minutes to hours (vestibular migraine, Ménière's), days to weeks (vestibular neuritis, stroke) 1, 2
• Triggers: Head position changes (BPPV), pressure changes (superior canal dehiscence), none (vestibular neuritis, stroke) 1, 2
• Associated symptoms: Hearing loss, tinnitus, aural fullness (Ménière's); headache, photophobia, phonophobia (vestibular migraine) 1, 2
• Medication review: Antihypertensives, sedatives, anticonvulsants, psychotropic drugs are leading causes of chronic dizziness 2, 3
• Vascular risk factors: Critical for acute vestibular syndrome to assess stroke risk 1, 2

Physical Examination

Mandatory Components

• Complete neurologic examination: Cranial nerves, cerebellar testing (finger-to-nose, heel-to-shin, rapid alternating movements), gait assessment 1, 3
• Nystagmus assessment: Direction, pattern (horizontal, vertical, torsional), presence at rest vs with gaze 1, 3
• Orthostatic blood pressure: Measure supine and after 1-3 minutes standing 4, 3
• Otologic examination: Tympanic membranes, hearing assessment 3

Syndrome-Specific Testing

• For triggered symptoms: Dix-Hallpike maneuver and supine roll test 1, 2, 3
• For acute persistent vertigo: HINTS examination (only if trained; unreliable when performed by non-experts) 1, 2
• For elderly or fall risk: Get Up and Go test, Tinetti Balance Assessment 1

Imaging Decisions

NO imaging indicated for:

• 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 indicated for:

• 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
• New severe headache 2

Critical imaging pitfall:

• CT head has very low yield (<1% diagnostic yield) for isolated dizziness and should NOT be used instead of MRI when stroke is suspected 1, 2
• CT sensitivity is only 20-40% for posterior circulation infarcts 2

Red Flags Requiring Urgent Evaluation

• Focal neurological deficits 2, 3
• Sudden hearing loss 2, 3
• Inability to stand or walk 2, 3
• New severe headache 2
• Downbeating nystagmus or other central nystagmus patterns 2
• Failure to respond to appropriate vestibular treatments 2

Laboratory Testing

Laboratory testing has minimal role in dizziness evaluation unless specific conditions are suspected 3:

• Consider basic metabolic panel only if dehydration or electrolyte abnormalities suspected 3
• Glucose if hypoglycemia suspected (though usually predicted by history/exam) 4
• No routine laboratory testing indicated for typical vestibular presentations 3

Management Based on Diagnosis

• BPPV: Canalith repositioning procedures (Epley maneuver) as first-line treatment with 90-98% success rates; no imaging or medication needed for typical cases 1, 2
• Vestibular migraine: Migraine prophylaxis and lifestyle modifications 1, 2
• Ménière's disease: Salt restriction and diuretics; intratympanic dexamethasone or gentamicin for refractory cases 1, 2
• Posterior circulation stroke: Activate stroke protocol immediately with urgent neurology consultation 1
• Persistent dizziness after initial treatment: Vestibular rehabilitation therapy significantly improves gait stability, particularly in elderly patients or those with heightened fall risk 2

Common 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 2
• Do not order routine imaging for isolated dizziness - yield is extremely low and most findings are incidental 2
• Do not perform HINTS examination if not properly trained - results are unreliable when performed by non-experts 2
• Do not order vestibular testing or imaging for straightforward BPPV with positive Dix-Hallpike - this delays treatment unnecessarily 2