What is the most appropriate testing for suspected vestibular neuritis?

Appropriate Testing for Suspected Vestibular Neuritis

For suspected vestibular neuritis, the most appropriate testing includes the head impulse test, caloric testing, and vestibular-evoked myogenic potentials, which should be ordered when the diagnosis is unclear or when atypical features are present. 1, 2

Clinical Diagnosis

• Vestibular neuritis is characterized by acute onset of rotatory vertigo lasting several days, horizontal spontaneous nystagmus toward the unaffected ear, and postural imbalance with falls toward the affected ear 3
• The diagnosis is primarily clinical, based on history and physical examination findings, including a positive head impulse test toward the affected ear 4, 2
• Vestibular neuritis is the most common cause of acute spontaneous vertigo and the third most common peripheral vestibular disorder after BPPV and Ménière's disease 2

Appropriate Testing Strategy

First-line Bedside Tests

• Head impulse test (HIT) - a pathologic response toward the affected ear is a hallmark diagnostic finding 3
• Evaluation of spontaneous nystagmus - horizontal-torsional nystagmus beating away from the lesion side 4
• Assessment of postural imbalance - typically with falling tendency toward the lesion side 4

Laboratory Vestibular Testing (When Indicated)

• Vestibular function testing should not be routinely ordered if the clinical diagnosis is clear 1
• Testing is appropriate when:
  • The diagnosis of vertigo/dizziness is unclear 1
  • The clinical presentation is atypical 1
  • Unusual nystagmus patterns are observed 1
  • Additional symptoms suggest accompanying CNS or otologic disorders 1
  • Multiple concurrent peripheral vestibular disorders are suspected 1

Specific Vestibular Tests When Indicated

• Caloric testing - demonstrates ipsilesional caloric paresis 4
• Vestibular-evoked myogenic potentials (VEMPs) - can differentiate between involvement of superior and inferior branches of the vestibular nerve 5
• Video head impulse test (vHIT) - can identify selective damage to specific semicircular canals 6

Neuroimaging Considerations

• Brain imaging (MRI) is indicated when the patient has:
  • Unprecedented headache 4
  • Negative head impulse test despite acute vertigo 4
  • Severe unsteadiness disproportionate to other symptoms 4
  • No recovery within 1-2 days 4
  • Additional neurological symptoms suggesting central pathology 7

Common Pitfalls to Avoid

• Ordering routine vestibular testing for clear clinical diagnoses leads to unnecessary costs and delays in treatment 1
• Normal vestibular test results do not necessarily rule out vestibular disorders 1
• Inferior vestibular neuritis (a rare subtype) may be misdiagnosed as a central vestibular disorder due to atypical features 4
• Results of vestibular testing often fluctuate throughout the course of vestibular disorders, and the degree of damage detected correlates poorly with patient-perceived disability 1

Testing Algorithm

1. Perform thorough clinical assessment including head impulse test
2. If diagnosis is clear with typical features, no additional testing is needed
3. Order vestibular function testing if:
   • Clinical presentation is atypical
   • Nystagmus patterns are unusual
   • Additional symptoms suggest other disorders
   • Patient fails to improve within expected timeframe
4. Consider neuroimaging if central pathology is suspected based on red flags