investigations

Last reviewed 01/2018

To exclude systemic conditions.

  • renal function, glucose - metabolic disturbances 
  • FBC, ESR, CRP - infections
  • TFT - hormonal imbalances (1)

For testing of hearing

  • pure tone audiometry:
    • to assess the level of hearing loss
    • initially, low frequencies are lost whihch resolves after an attack
    • later, loss of higher frequencies occurs, causing a more flattened audiogram
    • typically indicates a sensory type of hearing loss in the affected ear
    • speech discrimination is often diminished in the affected ear

For testing of balance

  • ENG (electronystagmograph) or video nystagmography
    • may be performed to evaluate balance function
    • procedure:
      • it is done in a darkened room
      • recording electrodes are placed near the eyes
      • warm and cool water or air are gently introduced into each ear canal
      • measurement of eye movements is used to test the balance system
      • in about 50% the balance function is reduced in the affected ear.
  • rotational testing (balance platform)

In addition, patients who are suspected of having Meniere's disease, should rule out acoustic neuroma (vestibular schwannoma) by having a magnetic resonance imaging of the internal auditory meatus.

Other tests which are used in specialist clinics include:

  • the bithermic caloric testing  an objective test of unilateral peripheral vestibular disease
  • ectrocochleography (ECoG) – measures the electrical activity of the inner ear
  • the vestibular evoked myogenic potential -
  • the video head-impulse test- to identify peripheral vestibular deficits

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