How do I assess an adult presenting with acute vertigo to distinguish peripheral from central causes and determine appropriate management?

Assessing Acute Vertigo in Adults

To distinguish peripheral from central vertigo, immediately perform the Dix-Hallpike maneuver and assess nystagmus characteristics—peripheral causes produce horizontal-torsional nystagmus with latency and fatigability, while central causes produce pure vertical or direction-changing nystagmus without latency, often accompanied by severe postural instability and additional neurological deficits. 1

Critical Red Flags Requiring Immediate Neuroimaging

Before proceeding with peripheral vertigo evaluation, identify these features that demand urgent MRI with diffusion-weighted imaging:

• Severe postural instability with falling (central lesions produce significantly worse balance impairment than peripheral disorders) 1, 2
• Downbeating nystagmus on Dix-Hallpike without torsional component 3, 1
• Pure vertical nystagmus (upbeating or downbeating) without rotatory component 3, 1
• Direction-changing nystagmus without head position changes (periodic alternating nystagmus) 3
• Baseline nystagmus present without provocative maneuvers 3, 1
• Any additional neurological symptoms: dysarthria, dysmetria, dysphagia, limb weakness, hemiparesis, truncal/gait ataxia, sensory or motor deficits, diplopia, or Horner's syndrome 1, 2
• New-onset severe headache with vertigo (may indicate vertebrobasilar stroke or hemorrhage) 1, 2
• Failure to respond to appropriate peripheral vertigo treatments 3, 1

Critical pitfall: Approximately 25% of patients with acute vestibular syndrome have cerebrovascular disease, rising to 75% in high vascular risk cohorts, and 10% of cerebellar strokes present identically to peripheral vestibular disorders. 1, 2, 4

Nystagmus Examination: The Key Differentiator

Peripheral Vertigo Nystagmus Pattern

• Horizontal with rotatory (torsional) component 1
• Unidirectional (beats in same direction regardless of gaze) 1
• Suppressed by visual fixation 1
• Fatigable with repeated testing 1
• Brief latency period (5-20 seconds) before onset 1

Central Vertigo Nystagmus Pattern

• Pure vertical without torsional component 3, 1
• Direction-changing without head position changes 3, 1
• Direction-switching with gaze (gaze-evoked) 1
• NOT suppressed by visual fixation 3, 1
• Persists without modification on repositioning maneuvers 1
• Does not fatigue 3, 1

Perform the Dix-Hallpike Maneuver Bilaterally

This is the single most important diagnostic test for peripheral vertigo. 1

Positive for BPPV (Peripheral):

• Torsional and upbeating nystagmus 1
• 5-20 second latency before onset 1
• Crescendo-decrescendo pattern 1
• Fatigues with repeat testing 1
• Resolves within 60 seconds 1

Concerning for Central Pathology:

• Immediate onset without latency 1
• Persistent nystagmus that doesn't resolve 1
• Purely vertical without torsional component 1, 5

If Dix-Hallpike is positive with typical peripheral findings, imaging is unnecessary. 1 Proceed immediately to canalith repositioning (Epley maneuver). 1

Categorize by Timing and Triggers

The American Academy of Otolaryngology-Head and Neck Surgery recommends this framework over descriptive terms: 1

Triggered Episodic Vestibular Syndrome (Brief, <1 minute)

• BPPV (42% of general practice vertigo cases): Episodes triggered by specific head/body position changes, no hearing loss, tinnitus, or aural fullness 3, 2
• Postural hypotension: Consider medication review 1

Acute Vestibular Syndrome (Continuous, days to weeks)

• Vestibular neuritis (41% of cases): Acute severe rotational vertigo lasting 12-36 hours, viral etiology, no hearing loss 2
• Labyrinthitis: Similar to vestibular neuritis but WITH hearing loss 2
• Posterior circulation stroke: Must be excluded—look for severe postural instability, additional neurological signs 1, 2

Spontaneous Episodic Vestibular Syndrome (Minutes to hours, no triggers)

• Ménière's disease (10% general practice, 43% specialty settings): Episodes lasting 20 minutes to 12 hours with fluctuating sensorineural hearing loss, tinnitus, and aural fullness—the fluctuating hearing loss is the key distinguishing feature 1, 2
• Vestibular migraine (14% of vertigo cases): Requires migraine symptoms (headache, photophobia, phonophobia, visual aura) during at least two vertiginous episodes; hearing loss is mild, absent, or stable (not fluctuating) 3, 1, 2
• Vertebrobasilar insufficiency: Episodes typically last less than 30 minutes, no hearing loss, gaze-evoked nystagmus, severe postural instability, may precede stroke by weeks or months 3, 1, 2

Chronic Vestibular Syndrome (Weeks to months)

• Anxiety disorders, medication side effects (antihypertensives, cardiovascular drugs, anticonvulsants, aminoglycosides), posterior fossa masses 1, 2

Duration of Episodes: Critical Discriminator

• Less than 1 minute: BPPV 1, 2
• Less than 30 minutes: Vertebrobasilar insufficiency (central) 1, 2
• 20 minutes to 12 hours: Ménière's disease 2
• Days to weeks (continuous): Vestibular neuritis, labyrinthitis, or stroke 1, 2

Associated Symptoms Assessment

Hearing Loss Pattern

• Fluctuating sensorineural hearing loss: Ménière's disease 1, 2
• Stable or absent hearing loss: Vestibular migraine 1
• Acute hearing loss with vertigo: Labyrinthitis 2
• No hearing loss: BPPV, vestibular neuritis, vertebrobasilar insufficiency 2

Perform Weber test—if abnormal, formal audiometry is mandatory to characterize the hearing loss. 1

Tinnitus and Aural Fullness

• Present in Ménière's disease, labyrinthitis, posttraumatic vertigo 1
• Absent in BPPV, vestibular neuritis, central causes 2

When NOT to Order Imaging

• Typical BPPV with positive Dix-Hallpike and no red flags: Imaging unnecessary 1
• Routine CT head for isolated dizziness: Diagnostic yield <1% 1
• MRI for typical BPPV: Only 4% diagnostic yield without red flags 1

When Additional Testing IS Required

• Atypical clinical presentation 1
• Equivocal or unusual nystagmus findings on Dix-Hallpike 1
• Additional symptoms suggesting CNS or otologic disorder 1
• Multiple concurrent peripheral vestibular disorders suspected (BPPV can coexist with Ménière's disease or vestibular neuritis) 3, 1

Immediate Management for Confirmed BPPV

• Perform Epley maneuver immediately upon diagnosis (80% success rate after 1-3 treatments, 90-98% with additional maneuvers) 1
• Do NOT prescribe vestibular suppressants for BPPV—they prevent central compensation 1
• Do NOT recommend postprocedural postural restrictions 1
• Reassess within 1 month to document resolution or persistence 1

Special Clinical Scenarios

Migraine with Vertigo

When both are present, consider: 1

1. Vestibular migraine (most common): Requires migraine symptoms during at least 50% of vertigo episodes, stable hearing 1
2. Ménière's disease: Distinguished by fluctuating hearing loss that worsens over time 1
3. BPPV: Perform Dix-Hallpike to confirm/exclude 1
4. Central causes: Exclude with neuroimaging if red flags present 1

Posttraumatic Vertigo

• BPPV is most often idiopathic, but traumatic brain injury is a recognized cause 3
• Can present with vertigo, disequilibrium, tinnitus, and headache 3, 2

Medication-Induced Vertigo

• Aminoglycosides (especially gentamicin): Vestibular toxicity may be irreversible 2
• Antihypertensives, cardiovascular drugs, anticonvulsants: Common culprits 1, 2
• Review all medications in every dizzy patient 1

Common Pitfalls to Avoid

• Overlooking subtle neurological signs that indicate central pathology 1, 2
• Missing cerebellar infarction that masquerades as peripheral vestibular lesion—MRI indicated for acute vertigo with profound imbalance 5, 4
• Failing to distinguish fluctuating vs. stable hearing loss (Ménière's vs. vestibular migraine) 1
• Under-recognizing vestibular migraine despite being extremely common (3.2% lifetime prevalence) 1, 2
• Assuming single diagnosis—multiple concurrent vestibular disorders can coexist 3, 1
• Delaying MRI when indicated—if vertigo hasn't improved under conservative treatment within 48 hours and central cause suspected, obtain MRI 4