How is Benign Paroxysmal Positional Vertigo (BPPV) diagnosed?

Diagnosis of Benign Paroxysmal Positional Vertigo (BPPV)

The diagnosis of BPPV is primarily confirmed through the Dix-Hallpike maneuver for posterior canal BPPV or the supine roll test for lateral canal BPPV, with characteristic nystagmus patterns being the definitive diagnostic finding. 1

Clinical History

• Patients typically report brief episodes of vertigo triggered by specific head position changes relative to gravity, such as rolling over in bed, looking up, or bending forward 1
• Episodes are usually brief, lasting less than 60 seconds 1
• Patients may describe rotational/spinning sensations or alternatively report lightheadedness, dizziness, nausea, or feeling "off balance" 1
• Approximately 50% of patients report subjective imbalance between classic BPPV episodes 1
• Many patients modify their movements to avoid triggering vertigo 1

Diagnostic Testing

Posterior Canal BPPV (most common, ~80-90% of cases)

• Dix-Hallpike Maneuver: The gold standard diagnostic test 1
  • Technique:
    • Position patient sitting upright
    • Turn patient's head 45 degrees to one side
    • Quickly move patient from sitting to supine with head extended 20 degrees below horizontal 1
    • Observe for nystagmus and vertigo 1
    • If negative on first side, test the opposite side 1
  • Positive test shows:
    • Latency period (typically 5-20 seconds) before onset of nystagmus and vertigo 1
    • Torsional, upbeating nystagmus toward the affected (downward) ear 1
    • Vertigo and nystagmus that increase and resolve within 60 seconds 1
    • Symptoms that fatigue with repeated testing 2

Lateral Canal BPPV (10-15% of cases)

• Supine Roll Test: The diagnostic test of choice when posterior canal testing is negative 3
  • Technique:
    • Position patient supine with head in neutral position
    • Quickly rotate head 90 degrees to one side, then the other 3
  • Positive test shows:
    • Horizontal nystagmus during head rotation 3
    • In geotropic type (most common): nystagmus beats toward the undermost ear 3
    • The side with stronger nystagmus typically indicates the affected ear 3

Diagnostic Criteria for BPPV

1. History of repeated episodes of vertigo with changes in head position 1
2. Characteristic nystagmus provoked by positioning tests 1
3. Latency period between test completion and onset of symptoms 1
4. Vertigo and nystagmus that resolve within 60 seconds 1

What NOT to Do

• Do not order routine neuroimaging: Clinicians should not order radiographic imaging in a patient who meets diagnostic criteria for BPPV in the absence of additional neurologic signs or symptoms 1
• Do not order vestibular testing: Comprehensive vestibular testing is unnecessary for patients who already meet clinical criteria for BPPV 1

Special Considerations

• In patients with physical limitations (cervical stenosis, severe kyphoscoliosis, limited cervical range of motion, morbid obesity), modifications to the diagnostic maneuvers may be necessary 1, 3
• If the initial Dix-Hallpike test is negative but clinical suspicion remains high, consider repeating the test as BPPV fatigue typically resolves within 30 minutes 2
• Up to one-third of cases with atypical histories of positional vertigo may still show positive Dix-Hallpike testing 1
• Consider alternative diagnoses if additional neurologic symptoms are present, particularly if nystagmus does not fatigue and cannot be suppressed by gaze fixation 4

Common Pitfalls

• Failing to test both sides during the Dix-Hallpike maneuver 5
• Not testing for lateral canal BPPV when posterior canal testing is negative 5
• Misinterpreting symptoms as another condition when BPPV presents atypically 6
• Overlooking BPPV when patients report dizziness rather than classic rotatory vertigo 6

By following this diagnostic approach, clinicians can accurately diagnose BPPV and proceed with appropriate treatment, typically involving canalith repositioning procedures specific to the affected canal 1, 2.