How do you differentiate between the different diseases of peripheral vertigo?

Differentiating Between Peripheral Vertigo Disorders

The most effective way to differentiate between peripheral vertigo disorders is by systematically evaluating the timing, triggers, duration of episodes, and associated symptoms, particularly focusing on the presence or absence of hearing loss and characteristic nystagmus patterns. 1, 2

Classification Framework

Peripheral vertigo disorders can be categorized into four distinct vestibular syndromes based on timing and triggers:

1. Acute Vestibular Syndrome

   • Continuous dizziness lasting days to weeks
   • Examples: Vestibular neuritis, labyrinthitis
   • Features: Nausea, vomiting, intolerance to head motion

2. Triggered Episodic Vestibular Syndrome

   • Episodes triggered by specific actions (usually position changes)
   • Duration typically <1 minute
   • Primary example: BPPV

3. Spontaneous Episodic Vestibular Syndrome

   • Episodes not triggered by specific actions
   • Duration: minutes to hours
   • Examples: Ménière's disease, vestibular migraine

4. Chronic Vestibular Syndrome

   • Dizziness lasting weeks to months or longer
   • Examples: Posttraumatic vertigo, medication side effects 1

Key Differentiating Features

Benign Paroxysmal Positional Vertigo (BPPV)

• Timing/Triggers: Brief episodes (seconds) triggered by position changes
• Nystagmus: Characteristic torsional or direction-changing horizontal nystagmus with positional testing
• Associated symptoms: No hearing loss
• Diagnostic test: Positive Dix-Hallpike maneuver or supine roll test
• Treatment response: Responds to canalith repositioning procedures 1, 3

Ménière's Disease

• Timing/Triggers: Discrete episodes lasting hours, spontaneous onset
• Associated symptoms: Fluctuating hearing loss, aural fullness, tinnitus in affected ear
• Diagnostic features: Characteristic audiometric findings
• Duration: Attacks typically last hours 1, 2

Superior Canal Dehiscence (SCD)

• Timing/Triggers: Vertigo induced by pressure changes (not position changes)
• Associated symptoms: Conductive hearing loss (lower bone-conducted thresholds)
• Diagnostic tests: CT temporal bones or vestibular evoked myogenic potential testing
• Unique feature: Pressure-related trigger (e.g., Valsalva) 1

Perilymph Fistula

• Timing/Triggers: Episodes triggered by pressure changes
• Associated symptoms: May have fluctuating hearing loss
• History: Often post-surgical or post-traumatic
• Differentiation from BPPV: Pressure-related rather than position-related triggers 1

Vestibular Neuritis

• Timing/Triggers: Acute onset, persistent vertigo lasting days
• Nystagmus: Unidirectional horizontal nystagmus
• Associated symptoms: No hearing loss
• Duration: Continuous symptoms gradually improving over days to weeks 3, 4

Labyrinthitis

• Timing/Triggers: Acute onset, persistent vertigo
• Associated symptoms: Hearing loss (distinguishes from vestibular neuritis)
• Duration: Continuous symptoms gradually improving over days to weeks 1

Diagnostic Approach

1. History Assessment:

   • Duration of episodes (seconds, minutes, hours, days)
   • Triggers (positional, pressure changes, spontaneous)
   • Associated symptoms (hearing loss, tinnitus, aural fullness)
   • Pattern of recurrence 2

2. Physical Examination:

   • Positional testing: Dix-Hallpike maneuver and supine roll test
   • HINTS examination: Head-Impulse, Nystagmus, Test of Skew (crucial for differentiating central from peripheral causes)
   • Nystagmus evaluation: Direction, duration, fatigability
   • Hearing assessment: Tuning fork tests, audiometry 2, 5

3. Nystagmus Patterns:

   • BPPV: Torsional/vertical (posterior canal) or horizontal (horizontal canal) nystagmus that is transient and fatigable
   • Vestibular neuritis: Unidirectional horizontal nystagmus
   • Central causes: Pure vertical (upbeating/downbeating) nystagmus, direction-changing without position changes, or nystagmus that doesn't fatigue 3, 6

Red Flags for Central Causes

Be alert for these signs that suggest central rather than peripheral vertigo:

• Downbeating nystagmus without torsional component
• Direction-changing nystagmus without head position changes
• Persistent nystagmus without provocation
• Failure to respond to repositioning maneuvers
• Associated neurological symptoms
• Severe imbalance out of proportion to vertigo 1, 6

Common Pitfalls to Avoid

1. Relying solely on symptom quality: Focus on timing and triggers rather than how patients describe their dizziness

2. Missing cerebellar infarction: Can present similar to peripheral vertigo but typically has profound imbalance; consider MRI in acute vertigo with severe imbalance

3. Overlooking medication causes: Always review medication regimens in chronic dizziness

4. Inadequate positional testing: Ensure proper technique for Dix-Hallpike and supine roll tests

5. Prolonged vestibular suppressant use: Should be short-term only as they interfere with central compensation 2, 6

By systematically evaluating these key features, clinicians can effectively differentiate between the various causes of peripheral vertigo and provide appropriate treatment to improve patient outcomes.