What is Benign Paroxysmal Positional Vertigo (BPPV)?

What is Benign Paroxysmal Positional Vertigo (BPPV)?

BPPV is an inner ear disorder characterized by brief, recurrent episodes of vertigo triggered by specific head position changes, caused by dislodged calcium carbonate crystals (otoconia) that migrate from the utricle into the semicircular canals and abnormally stimulate the vestibular system. 1

Definition and Core Characteristics

BPPV is defined by the following key features:

• Vertigo episodes: Brief attacks of rotational vertigo lasting seconds to minutes, triggered by changes in head position relative to gravity 1, 2
• Positional nature: Symptoms are provoked by specific movements such as lying down, rolling over in bed, looking up, or bending over 3
• Paroxysmal onset: Rapid and sudden onset of spinning sensations initiated by position changes 1
• Benign course: Not caused by serious central nervous system disorders, with favorable prognosis for recovery 1

Pathophysiology

The underlying mechanism involves displaced inner ear particles:

• Canalithiasis theory: Free-floating otoconia (calcium carbonate crystals) break loose from the utricle and migrate into the semicircular canals, creating abnormal forces during head movement 1, 3
• Canal distribution: The posterior semicircular canal is affected in 85-95% of cases due to its gravity-dependent position when supine, while the lateral (horizontal) canal accounts for 5-15% of cases 1, 3
• Cupular stimulation: The displaced crystals abnormally stimulate the cupula of the affected canal, producing vertigo and characteristic nystagmus 1, 2

Epidemiology and Clinical Impact

BPPV is remarkably common:

• Prevalence: Accounts for 17-42% of all vertigo cases, making it the most common cause of vertigo 1, 3
• Age distribution: More common in older adults, though many people will experience it at some point in their lives 3
• Clinical burden: Despite the term "benign," untreated BPPV significantly impacts quality of life, increases fall risk, and impairs performance of daily activities 1

Clinical Presentation

Typical symptoms include:

• Vertigo spells: Distinct triggered episodes of spinning sensations lasting seconds to minutes 3
• Associated symptoms: Nausea (sometimes vomiting), severe disorientation in space, and sense of instability or imbalance 1
• Positional triggers: Symptoms provoked by rolling over in bed, looking up, bending over, or sitting up 1, 3
• Natural course: The first episode is typically the most severe, with subsequent episodes often less intense; spontaneous resolution occurs in approximately 20% of patients by 1 month and up to 50% at 3 months 1

Important Distinctions

BPPV does NOT cause:

• Constant severe dizziness unaffected by position or movement 1
• Hearing loss 1
• Loss of consciousness or fainting 1

Diagnosis

Diagnosis is primarily clinical:

• Bedside testing: The Dix-Hallpike maneuver for posterior canal BPPV and the supine roll test for lateral canal BPPV are the diagnostic standards 1, 3
• Characteristic nystagmus: Torsional nystagmus with brief latency after positioning is pathognomonic for posterior canal BPPV 4, 2
• No imaging required: Normal medical imaging (scans, x-rays) and laboratory testing cannot confirm BPPV; diagnosis relies on clinical examination 1, 3

Etiology

Most cases occur spontaneously, but recognized precipitating factors include:

• Trauma: Head or neck injury, particularly in patients younger than 50 years 3
• Associated conditions: Migraine, other inner ear problems, diabetes, osteoporosis 1
• Prolonged bed rest: Extended periods lying in bed (post-surgical, illness, preferred sleep side) 1
• Idiopathic: Approximately 50% of cases have no identifiable cause 4

Treatment Principles

The mechanical nature of BPPV makes it highly treatable:

• Canalith repositioning procedures (CRPs): Specific body position sequences designed to relocate dislodged particles back to the utricle, with success rates around 80% in 1-3 treatments 1, 3
• Medication role: Not typically used for treatment except for immediate symptom relief (nausea control); vestibular suppressants like antihistamines and benzodiazepines are options but not primary therapy 1, 3
• Observation option: May be appropriate for initial management given the potential for spontaneous resolution 1

Clinical Pitfalls

Common diagnostic errors to avoid:

• Underdiagnosis: BPPV is frequently missed despite being the most common cause of peripheral vertigo 3
• Incomplete examination: Failure to perform both Dix-Hallpike and supine roll tests may miss lateral canal BPPV 3
• Central causes: Atypical nystagmus patterns or failure to respond to appropriate treatment should raise concern for central nervous system disorders masquerading as BPPV 5
• Cervical precautions: Exercise caution when performing diagnostic maneuvers in patients with cervical stenosis, severe kyphoscoliosis, or limited cervical range of motion 3