What are the diagnostic criteria and treatment options for vestibular neuritis?

Diagnosis and Treatment of Vestibular Neuritis

Vestibular neuritis is diagnosed based on the clinical presentation of sudden severe vertigo lasting more than 24 hours without hearing loss, tinnitus, or other neurological symptoms, and confirmed through specific vestibular function tests including the head impulse test showing unilateral vestibular deficit.

Diagnostic Criteria

Vestibular neuritis is characterized by:

• Clinical presentation:

  • Abrupt onset of true-whirling vertigo lasting >24 hours 1
  • Severe vertigo with prolonged nausea and vomiting 2
  • No associated hearing loss, tinnitus, or aural fullness 2, 1
  • No other neurological symptoms or signs 1

• Physical examination findings:

  • Horizontal spontaneous nystagmus (with rotational component) toward the unaffected ear 3
  • Pathologic head-impulse test toward the affected ear 3
  • Deviation of subjective visual vertical toward the affected ear 3
  • Postural imbalance with falls toward the affected ear 3

• Diagnostic tests:

  • Head impulse test: Shows abnormal vestibulo-ocular reflex toward the affected side 1, 3
  • Bithermal caloric test: Reveals reduced or absent caloric response on the affected side 1, 4
  • Vestibular-evoked myogenic potential (VEMP) test: May show abnormalities 1
  • HINTS examination (Head Impulse, Nystagmus, Test of Skew): More sensitive than early MRI for stroke detection in acute vestibular syndrome 2

Differential Diagnosis

It's crucial to distinguish vestibular neuritis from:

1. Central causes of vertigo (stroke, vertebrobasilar insufficiency):

   • Central causes present with nystagmus that doesn't fatigue, isn't suppressed by gaze fixation, and may have additional neurological signs 2
   • Down-beating nystagmus on Dix-Hallpike maneuver, direction-changing nystagmus without head position changes 2
   • Abnormal HINTS examination 2

2. Other peripheral vestibular disorders:

   • BPPV: Brief positional vertigo lasting seconds 2
   • Ménière's disease: Episodic vertigo with hearing loss, tinnitus, aural fullness 2
   • Labyrinthitis: Sudden severe vertigo with hearing loss 2
   • Vestibular migraine: Attacks lasting hours to >24 hours, often with migraine history 2

Treatment Options

Treatment for vestibular neuritis includes:

1. Symptomatic therapy:

   • Vestibular suppressants (e.g., meclizine 25-100 mg daily in divided doses) 5, 1
     • Should be used only for the first several days as prolonged use may impede central vestibular compensation 6
   • Antiemetics for nausea and vomiting 1, 6
   • Generalized supportive care 1

2. Specific drug therapy:

   • Corticosteroids: Early treatment with oral steroids accelerates recovery of vestibular function 6
     • Most beneficial when started within 3 days of symptom onset 6
     • May improve recovery rate to 62% within 12 months 3
   • Antiviral therapy: Limited evidence for efficacy 1
   • Vasodilator therapy: Limited evidence for efficacy 1

3. Vestibular rehabilitation therapy:

   • Early resumption of normal activity to promote compensation 6
   • Generalized and customized vestibular exercises 1
   • Directed vestibular rehabilitation therapy to promote central compensation 6

Prognosis

• Most patients recover well from vestibular neuritis, even without treatment 6
• The disease typically follows a benign course of between 2 days and 6 weeks 7
• Mild transitory episodes of dizziness may recur over 12-18 months 7
• Recovery is due to a combination of peripheral restoration of labyrinthine function (usually incomplete), somatosensory and visual substitution, and central compensation 3

Common Pitfalls to Avoid

• Missing central causes of vertigo by not performing the HINTS examination 2
• Prolonged use of vestibular suppressants, which may impede central vestibular compensation 6
• Failing to consider stroke in patients with acute vestibular syndrome who have vascular risk factors 6
• Ordering unnecessary imaging studies in patients with clear peripheral vertigo 2