How is Benign Paroxysmal Positional Vertigo (BPPV) diagnosed?

Diagnosis of Benign Paroxysmal Positional Vertigo (BPPV)

The Dix-Hallpike maneuver is the gold standard diagnostic test for posterior canal BPPV, with a positive test showing characteristic nystagmus after a latency period, while the supine roll test is used to diagnose horizontal canal BPPV. 1

Clinical History

The diagnosis of BPPV begins with identifying its characteristic clinical presentation:

• Brief episodes of vertigo triggered by specific head position changes relative to gravity (rolling over in bed, looking upward, bending forward) 2, 1
• Episodes typically last less than 60 seconds 2, 1
• Patients may describe rotational/spinning sensations or alternatively report lightheadedness, dizziness, nausea, or feeling "off balance" 2
• Approximately 50% of patients report subjective imbalance between classic BPPV episodes 2
• Many patients modify their movements to avoid triggering vertigo 1
• BPPV fits the "triggered episodic vestibular syndrome" criteria given its positional trigger and brief episodic occurrences 2

Diagnostic Testing for Posterior Canal BPPV

The Dix-Hallpike maneuver is the primary diagnostic test for posterior canal BPPV:

• Technique:

  • Begin with patient in upright seated position 2
  • Rotate patient's head 45 degrees to one side (testing that ear) 2
  • Quickly move patient from sitting to supine with head extended 20 degrees below horizontal 2
  • Observe for nystagmus and vertigo 2
  • Repeat for opposite side 2

• Positive Dix-Hallpike test shows:

  • Latency period of 5-20 seconds (rarely up to 1 minute) before onset of nystagmus and vertigo 2
  • Torsional, upbeating nystagmus toward the affected ear 1
  • Vertigo and nystagmus that increase and resolve within 60 seconds 2

Diagnostic Testing for Horizontal Canal BPPV

The supine roll test is used for diagnosing horizontal canal BPPV:

• Technique:

  • Position patient supine with head in neutral position 1
  • Quickly rotate head 90 degrees to one side, then the other 1

• Positive supine roll test shows:

  • Horizontal direction-changing nystagmus during head rotation 2, 1
  • In geotropic form (beating toward ground): the side with strongest nystagmus is the affected ear 2
  • In apogeotropic form (beating away from ground): the side opposite the strongest nystagmus is the affected ear 2

Diagnostic Criteria for BPPV

BPPV diagnosis is confirmed when:

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

Differential Diagnosis

BPPV must be differentiated from other causes of vertigo:

• Otologic disorders: Ménière's disease, vestibular neuritis, labyrinthitis, superior canal dehiscence syndrome, posttraumatic vertigo, perilymphatic fistula 2
• Neurologic disorders: Vestibular migraine, posterior circulation TIA/stroke, demyelinating diseases, CNS lesions 2
• Other entities: Anxiety/panic disorder, cervicogenic vertigo, medication side effects, postural hypotension 2

Key Diagnostic Pearls

• In up to one-third of cases with atypical histories of positional vertigo, Dix-Hallpike testing will still reveal positional nystagmus, supporting BPPV diagnosis 2
• Nystagmus findings that suggest central causes rather than BPPV include downbeating nystagmus without torsional component and direction-changing nystagmus occurring without changes in head position 2
• Bilateral posterior canal BPPV is more likely after head trauma 2
• Factors affecting diagnostic accuracy include speed of movements during testing, time of day, and angle of occiput during maneuver 2

Important Cautions

• The Dix-Hallpike maneuver should be avoided in patients with cervical stenosis, severe kyphoscoliosis, limited cervical range of motion, carotid sinus syncope, or unstable heart disease 1
• Clinicians should not order routine neuroimaging in patients who meet diagnostic criteria for BPPV without additional neurologic signs/symptoms 1
• Comprehensive vestibular testing is unnecessary for patients who already meet clinical criteria for BPPV 1
• If symptoms persist despite appropriate treatment, consider reevaluation for other causes of vertigo 3