What is the appropriate evaluation and management of a patient presenting with acute dizziness?

Management of Acute Dizziness

Categorize acute dizziness by timing and triggers—not by the patient's vague description of "spinning" versus "lightheadedness"—to determine whether you are dealing with a benign peripheral vestibular disorder or a life-threatening stroke. 1

Initial Classification: The Timing and Triggers Approach

The first step is to classify the presentation into one of three categories based on duration and precipitants 1, 2, 3:

1. Acute Vestibular Syndrome (AVS)

• Duration: Days to weeks of continuous vertigo 1
• Key differential: Vestibular neuritis versus posterior circulation stroke
• Critical fact: 25% of AVS cases are stroke, rising to 75% in high vascular risk patients 1
• Major pitfall: 75-80% of posterior circulation stroke patients have NO focal neurologic deficits on standard examination 4

2. Triggered Episodic Vestibular Syndrome

• Duration: Seconds to minutes, provoked by head position changes 1
• Primary diagnosis: Benign Paroxysmal Positional Vertigo (BPPV)—accounts for 42% of all vertigo cases 1

3. Spontaneous Episodic Vestibular Syndrome

• Duration: Minutes to hours, unprovoked 1
• Key differential: Vestibular migraine (14% of cases) versus Ménière's disease versus TIA 1

Critical History Elements

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

• Exact duration: Seconds = BPPV; minutes-hours = migraine/Ménière's; days-weeks = neuritis/stroke 1
• Triggers: Position changes (BPPV) versus spontaneous (neuritis/stroke/migraine) 1
• Associated symptoms:
  • Hearing loss + tinnitus + aural fullness = Ménière's disease 1
  • Headache + photophobia + phonophobia = vestibular migraine 1
  • Sudden unilateral hearing loss = RED FLAG requiring urgent imaging 4
• Vascular risk factors: Age >50, hypertension, diabetes, atrial fibrillation, prior stroke 1, 2

Physical Examination: The Bedside Tests That Matter

For Acute Vestibular Syndrome (Continuous Vertigo)

Perform the HINTS examination (Head Impulse, Nystagmus, Test of Skew) 1, 2:

• Sensitivity: 100% for stroke when performed by trained practitioners versus only 46% for early MRI 1
• Central features suggesting stroke:
  • Normal head impulse test (vestibulo-ocular reflex intact) 1, 4
  • Direction-changing or vertical nystagmus 1
  • Skew deviation present 1

Warning: HINTS is unreliable when performed by non-experts 1

For Triggered Episodic Vertigo

Perform the Dix-Hallpike maneuver bilaterally 1, 2:

• Positive findings for BPPV:
  • Latency of 5-20 seconds before symptoms begin 1
  • Torsional, upbeating nystagmus toward the affected ear 1
  • Vertigo and nystagmus increase then resolve within 60 seconds 1

Also perform supine roll test for horizontal canal BPPV 2

Complete Neurologic Examination

Check for focal deficits including diplopia, dysarthria, facial numbness, limb weakness, ataxia 4, 2

Orthostatic Vital Signs

Measure blood pressure and heart rate supine and after 3 minutes standing 1

Red Flags Requiring Immediate MRI and Neurology Consultation

These findings mandate urgent imaging regardless of other reassuring features 4:

• Focal neurological deficits (diplopia, dysarthria, facial numbness, limb weakness) 4
• Inability to stand or walk independently 4
• New severe headache accompanying dizziness 4
• Sudden unilateral hearing loss 4
• Downbeating nystagmus or other central nystagmus patterns 4
• Abnormal HINTS examination (normal head impulse, direction-changing nystagmus, skew deviation) 4
• Failure to respond to appropriate vestibular treatment 4

Imaging Decisions: When to Order and What to Order

DO NOT IMAGE:

• Brief episodic vertigo with positive Dix-Hallpike test and no red flags 1, 2
• Acute persistent vertigo with normal neurologic exam AND peripheral HINTS findings by trained examiner 1
• Diagnostic yield of CT in isolated dizziness is <1% 1, 4

ORDER MRI BRAIN WITHOUT CONTRAST:

• Any red flag present 1, 4
• Abnormal neurologic examination 1, 2
• HINTS examination suggesting central cause 1, 2
• High vascular risk patients with acute vestibular syndrome, even with normal neurologic exam (11-25% have stroke) 1, 2
• Unilateral or pulsatile tinnitus 1, 2
• Asymmetric hearing loss 1, 2

ORDER MRI HEAD AND IAC WITH AND WITHOUT CONTRAST:

• Chronic recurrent vertigo with unilateral hearing loss or tinnitus to exclude vestibular schwannoma 1, 2

CT HEAD:

• Only as initial imaging in acute settings when stroke suspected but MRI unavailable 1
• Critical limitation: CT misses most posterior circulation infarcts with sensitivity of only 20-40% 4

DO NOT ORDER:

• CTA head/neck for isolated dizziness (diagnostic yield only 3%, sensitivity 14%) 1
• Routine laboratory panels (very low yield unless specific abnormality suspected) 1
• Exception: Check fingerstick glucose immediately (hypoglycemia is most common unexpected finding) 1

Immediate Management by Diagnosis

BPPV (Positive Dix-Hallpike)

Perform canalith repositioning procedure (Epley maneuver) immediately 1, 2, 5:

• Success rate: 80% after 1-3 treatments, 90-98% with repeat maneuvers 1, 2
• No imaging or medication needed for typical cases 1
• Counsel about 10-18% recurrence risk at one year, up to 36% long-term 2
• Address fall risk, especially in elderly (BPPV present in 9% of elderly, three-fourths had fallen within 3 months) 1

Vestibular Neuritis (Peripheral HINTS, No Red Flags)

Acute symptom management 6:

• Antiemetics: Metoclopramide 10 mg IM once or twice daily 6
• Vestibular suppressants: Diazepam 10 mg IM once or twice daily (short-term only, 2-3 days maximum) 6
• Position patient on healthy side with head/trunk raised 20 degrees 6

Early mobilization and vestibular rehabilitation 1, 2:

• Begin vestibular rehabilitation therapy early—significantly improves gait stability compared to medication alone 1
• Particularly beneficial for elderly patients or those with heightened fall risk 1

Posterior Circulation Stroke (Central HINTS or Red Flags)

• Immediate MRI brain without contrast 1, 4
• Urgent neurology consultation 4
• Do not delay imaging for "observation" 4

Vestibular Migraine

• Migraine prophylaxis and lifestyle modifications 1
• Acute treatment with standard migraine abortive therapy 1

Ménière's Disease

• Salt restriction (though evidence for specific sodium levels is lacking) 7
• Diuretics 1
• Intratympanic treatments for refractory cases 7, 1

Medication Review: A Leading Reversible Cause

Always review medications as a primary cause of chronic vestibular syndrome 1:

• Antihypertensives 1
• Sedatives 1
• Anticonvulsants 1
• Psychotropic drugs 1

Common Pitfalls to Avoid

1. Do not rely on patient's description of "spinning" versus "lightheadedness"—focus on timing and triggers instead 1, 4

2. Do not assume normal neurologic exam excludes stroke—75-80% of posterior circulation stroke patients have no focal deficits 4

3. Do not use CT instead of MRI when stroke is suspected—CT misses most posterior circulation infarcts 4

4. Do not order routine imaging for typical BPPV—diagnostic yield is extremely low and delays effective treatment 1, 4

5. Do not skip bedside testing—Dix-Hallpike and HINTS provide more diagnostic value than imaging in most cases 4

6. Do not overlook vestibular migraine—accounts for 14% of all vertigo cases but is extremely under-recognized, especially in young patients 1

7. Do not prescribe vestibular suppressants long-term—they impair central compensation and prolong recovery 5

Follow-Up

• BPPV patients: Reassess within one month to document resolution or persistence 1
• Vestibular neuritis: Continue vestibular rehabilitation until balance normalizes 1
• Persistent symptoms despite appropriate treatment: Consider MRI to exclude central pathology 4