How can you determine which ear is causing vertigo?

Determining Which Ear is Causing Vertigo

The most effective way to determine which ear is causing vertigo is through specific diagnostic maneuvers, particularly the supine roll test for lateral canal BPPV and the Dix-Hallpike maneuver for posterior canal BPPV, with interpretation of the resulting nystagmus pattern. 1

Posterior Canal BPPV (Most Common Type)

• Perform the Dix-Hallpike maneuver by quickly moving the patient from sitting to a supine position with the head turned 45 degrees to one side and extended about 20 degrees below horizontal 1, 2
• The affected ear is the one that, when positioned downward during the Dix-Hallpike test, produces characteristic torsional upbeating nystagmus with:
  • A brief latency period (typically 5-20 seconds)
  • Crescendo-decrescendo pattern of nystagmus
  • Resolution within 60 seconds 1, 2
• The nystagmus will typically beat toward the affected (downward) ear 2

Lateral Canal BPPV (10-15% of BPPV Cases)

• Perform the supine roll test by positioning the patient supine with head neutral, then quickly rotating the head 90 degrees to each side 1
• For geotropic type (most common):
  • The affected ear is the side where rolling produces the strongest nystagmus beating toward the ground 1
• For apogeotropic type:
  • The affected ear is the side opposite to where rolling produces the strongest nystagmus beating away from the ground 1

Additional Methods for Determining the Affected Ear in Lateral Canal BPPV

When standard testing is inconclusive (occurs in ~20% of cases), use these additional techniques 1:

• Lying-down nystagmus test: Move patient from sitting to straight supine facing up

  • Geotropic type: Nystagmus beats away from the affected ear
  • Apogeotropic type: Nystagmus beats toward the affected ear 1

• Head pitch test: In supine position, have patient sit up with head bending down

  • Geotropic type: Nystagmus usually beats toward the affected ear
  • Apogeotropic type: Nystagmus beats away from the affected ear 1

• Bow and lean test: Observe nystagmus when patient bends head forward (bowing) and backward (leaning)

  • Geotropic type:
    • Bowing: Nystagmus beats toward the affected ear
    • Leaning: Nystagmus beats away from the affected ear
  • Apogeotropic type:
    • Bowing: Nystagmus beats away from the affected ear
    • Leaning: Nystagmus beats toward the affected ear 1

Clinical Pearls and Pitfalls

• If posterior canal BPPV converts to horizontal nystagmus during positioning, the affected ear is the same as was affected by the posterior canal BPPV 1

• Clear lateralization remains unclear in about 20% of lateral canal BPPV cases despite testing; in such situations, consider treating one side and then the other 1

• Exercise caution when performing these tests in patients with:

  • Cervical stenosis
  • Limited cervical range of motion
  • Severe kyphoscoliosis
  • Rheumatoid arthritis
  • Cervical radiculopathies
  • Ankylosing spondylitis
  • Spinal cord injuries
  • Morbid obesity 1

• Always differentiate BPPV from other causes of vertigo, including:

  • Ménière's disease
  • Vestibular neuritis
  • Labyrinthitis
  • Vestibular migraine
  • Cerebrovascular events 1, 3, 4

• The diagnostic accuracy of the Dix-Hallpike maneuver varies: sensitivity of 82% and specificity of 71% among specialists, with a positive predictive value of 83% but lower negative predictive value of 52% in primary care settings 1, 2