Labyrinthitis: inflammation of the labyrinth

Vestibular neuritis: inflammation of the vestibular nerve

Aetiology

• Inflammatory disorder, most commonly viral inflammation
• Labyrinthitis should be distinguished from vestibular neuritis as there are important differences
  • Vestibular neuritis is used to define cases in which only the vestibular nerve is involved, hence there is no hearing impairment
  • Labyrinthitis is used when both the vestibular nerve and the labyrinth are involved, usually resulting in both vertigo and hearing impairment

Clinical features

Symptoms

• Vertigo
  • Prolonged (days)
  • Not triggered by movement but exacerbated by movement
• Nausea and vomiting
• Labyrinthitis is associated with tinnitus or hearing loss (not seen in vestibular neuritis)
  • Hearing loss in labyrinthitis may be unilateral or bilateral, with varying severity
• Preceding or concurrent symptoms of upper respiratory tract infection

Signs of labrynthitis

• Spontaneous unidirectional horizontal nystagmus towards the unaffected side
• Sensorineural hearing loss: shown by Rinne's test and Weber test
• Abnormal head impulse test: signifies an impaired vestibulo-ocular reflex
• Gait disturbance: the patient may fall towards the affected side

Management

• Episodes are usually self-limiting
• Prochlorperazine or antihistamines may help reduce the sensation of dizziness
• May require further investigation if prolonged or atypical