Are viral infections associated with vestibular neuritis?

Viral Infections and Vestibular Neuritis

Yes, viral infections are strongly associated with vestibular neuritis, with herpes simplex virus type 1 (HSV-1) being the most commonly implicated pathogen. 1

Pathophysiology and Viral Etiology

Vestibular neuritis is characterized by a sudden unilateral loss of vestibular function, resulting in vertigo, nausea, and imbalance. The condition is considered inflammatory in nature, with several lines of evidence supporting viral involvement:

• Herpes Simplex Virus (HSV-1): HSV-1 has been detected in human vestibular ganglia through PCR studies, confirming its ability to establish latent infections in the vestibular system 2

  • HSV-1 DNA was found in 60% of vestibular ganglia in autopsy studies
  • Latency-associated transcripts (LAT) of HSV-1 were detected in 63% of vestibular ganglia using RT-PCR

• Clinical Associations: Approximately 30% of patients with vestibular neuritis report a flu-like illness preceding the onset of vertigo symptoms, suggesting a viral trigger 3

• Other Viral Agents: While HSV-1 is the primary suspect, other viruses have been implicated in vestibular neuritis, including:

  • SARS-CoV-2 (COVID-19) 4, 5
  • Adenovirus (including vaccine vector-based) 6

Clinical Presentation and Diagnosis

Patients with vestibular neuritis typically present with:

• Sudden onset of severe vertigo
• Nausea and vomiting
• Horizontal-torsional spontaneous nystagmus
• Positive head impulse test
• Absence of auditory symptoms (distinguishing it from labyrinthitis)
• Absence of other neurological symptoms 3

Diagnostic Approach:

1. HINTS examination (Head-Impulse, Nystagmus, Test of Skew) to distinguish peripheral from central causes of vertigo 7
2. Caloric testing to assess vestibular function
3. MRI to rule out central pathology, especially in cases with atypical presentation 7

Emerging Evidence: COVID-19 and Vestibular Neuritis

Recent case reports have documented vestibular neuritis following COVID-19 infection and vaccination:

• A 57-year-old man developed vestibular neuritis following COVID-19 infection, with evidence of right superior vestibular neuritis on video head impulse testing 4
• A 42-year-old physician caring for COVID-19 patients developed acute vestibular neuritis two weeks after a mild respiratory illness later confirmed as COVID-19 5
• A case of acute vestibular neuritis was reported 11 days after adenoviral vector-based COVID-19 vaccination 6

Treatment Approaches

The management of vestibular neuritis involves:

1. Corticosteroids: Early administration of corticosteroids is recommended as causal treatment, targeting the inflammatory process 3

2. Symptomatic relief:

   • Vestibular suppressants for acute symptoms
   • Prokinetic antiemetics for nausea and vomiting 7

3. Vestibular rehabilitation: Self-administered or clinician-guided therapy to promote central compensation 7

   • Particularly beneficial for elderly patients
   • May decrease recurrence rates

4. Antiviral agents: Studies have not demonstrated improved outcomes with antiviral medications despite the viral etiology 3

Prognosis and Follow-up

• Most patients show significant improvement within 1-2 weeks
• Complete resolution of symptoms may take several months
• Approximately 30-50% of patients may have residual symptoms or incomplete vestibular compensation
• Follow-up within one month is recommended to assess recovery 7

Clinical Pitfalls and Considerations

• Misdiagnosis risk: Vestibular neuritis can be mistaken for central causes of vertigo, including stroke. The HINTS examination is more sensitive than early MRI for detecting stroke in patients with acute vertigo 7

• Bilateral involvement: While vestibular neuritis is typically unilateral, bilateral involvement should raise suspicion for alternative diagnoses 1

• Recurrence: Patients should be counseled about the possibility of recurrence and taught to recognize early signs 7

• Fall risk: Particularly important in elderly patients who may require additional safety precautions during recovery 7

In conclusion, the evidence strongly supports a viral etiology for vestibular neuritis, with HSV-1 being the most commonly implicated pathogen. Recent evidence also suggests SARS-CoV-2 may trigger vestibular neuritis in some patients.