What is peripheral vertigo?

Peripheral Vertigo: Understanding the Disorder

Peripheral vertigo is a form of vertigo caused by dysfunction of the peripheral vestibular system in the inner ear, characterized by an illusory sensation of motion due to abnormal stimulation of the vestibular apparatus. 1

Definition and Characteristics

Peripheral vertigo refers specifically to vertigo originating from disorders of the vestibular apparatus within the inner ear, as opposed to central vertigo which stems from problems in the brain. The key characteristics include:

• Sensation: An illusory sensation of motion (spinning) of either self or surroundings in the absence of true motion 1
• Origin: Dysfunction in the peripheral vestibular system including the semicircular canals, vestibule, and vestibular nerve 1
• Presentation: Often presents with acute onset of vertigo, loss of balance, and a sensation of spinning that worsens with head movement 1
• Associated symptoms: May include nausea, vomiting, and unsteadiness but typically without other neurological deficits 1, 2

Common Causes of Peripheral Vertigo

Benign Paroxysmal Positional Vertigo (BPPV)

• Most common cause of peripheral vertigo (85-95% of cases) 1
• Characterized by brief episodes of vertigo triggered by specific changes in head position relative to gravity 1
• Pathophysiology: Typically caused by canalithiasis - dislodged otoconia (calcium carbonate crystals) that have moved from the utricle into the semicircular canals 1, 3
• Duration: Episodes typically last seconds to less than a minute 1
• Not associated with hearing loss, tinnitus, or aural fullness 1

Other Common Causes

• Vestibular neuritis/labyrinthitis: Viral infection of the vestibular nerve or labyrinth causing prolonged vertigo (>24 hours) 1
• Ménière's disease: Characterized by episodic vertigo lasting hours, with fluctuating hearing loss, tinnitus, and aural fullness 1
• Labyrinthitis: Sudden severe vertigo with hearing loss and prolonged symptoms 1

Differentiating Peripheral from Central Vertigo

Key Differentiating Features

• Neurological symptoms: Peripheral vertigo typically occurs without other neurological deficits, while central vertigo often has associated neurological findings 2
• Nystagmus patterns: Different patterns of nystagmus (involuntary eye movements) help distinguish between peripheral and central causes 1
• Duration of symptoms: Peripheral vertigo episodes often have characteristic durations based on the specific cause 2
• Response to position changes: Peripheral vertigo is often provoked or worsened by specific head positions 1

Warning Signs of Central Vertigo

Findings that suggest central rather than peripheral vertigo include:

• Downbeating nystagmus without torsional component
• Direction-changing nystagmus occurring without changes in head position
• Baseline nystagmus without provocative maneuvers
• Associated neurological symptoms (dysarthria, dysmetria, dysphagia, sensory or motor deficits)
• Failure to respond to appropriate repositioning maneuvers 1

Diagnostic Approach

The diagnosis of peripheral vertigo is primarily clinical:

• Detailed history focusing on onset, duration, triggers, and associated symptoms
• Examination for nystagmus and balance disturbances
• Specific positional tests (e.g., Dix-Hallpike test for posterior canal BPPV, supine roll test for lateral canal BPPV) 1
• Normal medical imaging (scans and x-rays) and laboratory testing cannot confirm peripheral vertigo conditions like BPPV 1

Management Principles

Treatment depends on the specific cause of peripheral vertigo:

• For BPPV: Canalith repositioning procedures (CRPs) are highly effective (80% success rate with 1-3 treatments) 1
• For vestibular neuritis: Vestibular rehabilitation exercises to promote central compensation 4
• For Ménière's disease: Dietary modifications, diuretics, and sometimes surgical interventions 1

Clinical Pitfalls and Caveats

1. Misdiagnosis risk: Central causes of vertigo (especially cerebellar stroke) can sometimes mimic peripheral vertigo. MRI is indicated in any patient with acute vertigo and profound imbalance suspected to be cerebellar infarct or hemorrhage 2

2. Medication caution: Inappropriate use of vestibular suppressant medications can delay recovery and central compensation in peripheral vertigo 1, 5

3. Chronic symptoms: The natural course of peripheral vertigo conditions like BPPV is to become less severe over time, with the first episode often being the worst 1

4. Elderly patients: In seniors, BPPV may present as isolated instability with position changes rather than classic vertigo, increasing fall risk 1

5. Recurrence potential: Some forms of peripheral vertigo, particularly BPPV, may recur and require repeated treatment 1

By understanding the specific characteristics and management approaches for peripheral vertigo, clinicians can provide effective treatment and significantly improve patients' quality of life.