Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing Loss should be regarded as an otologic emergency.

  • A patient should be evaluated by otolaryngologist ENT specialist).

  • A thorough history, physical examination, appropriate laboratory and radiologic investigations including gadolinium-enhanced MRI, and Audiometry tests should be carried out to find out the known cause.

  • A tapering course of steroid is prescribed.

  • Antiviral medication may be considered.

What is Sudden Sensorineural Hearing Loss?

Sudden Sensorineural Hearing Loss is defined as a hearing reduction greater than 30 dB, over at least 3 consecutive frequencies (on pure tone audiogram), occurring over or less than 3 days. Maybe mild to severe reduction of hearing, usually affects one ear and there may be tinnitus and dizziness.

Most People (30-65%) may have a spontaneous recovery; others may have permanent hearing difficulties.

Causes of Sudden Hearing Loss

There is no conclusive evidence as to why it happens but some theories are suggested:

  • Generally, 90% cases are idiopathic where the cause is not known. Viral diseases appear to be the most common cause (about 60% cases) as shown by association with herpes.

  • There may be partial or complete blockage of circulation or vascular spasm to inner ear and nerves of hearing.

  • There may be rupture of delicate inner ear membrane after strong physical activity or sudden change in barometric pressure (flying/scuba diving).

  • The immune theory may play a role, because of its association with Cogan syndrome, SLE, Lupus, and AIDS.

Treatment of Sudden Sensorineural Hearing Loss
It is an otologic emergency and challenge to otolaryngologist.

Thorough history, physical examination, appropriate laboratory and radiologic investigations including gadolinium enhanced MRI, and Audiometry tests should be carried out to find out known cause such as:– Infection (bacterial-meningitis/viral-mumps, herpes), Tumor, Trauma, Acoustic trauma, Ototoxic drugs (amino glycoside antibiotics), and Systemic diseases (hypothyroidism, Diabetes mellitus).

If an etiologiy is apparent, appropriate treatment may be initiated such as antibiotics for infection, withdrawal of ototoxic drugs.

In most cases cause remains unknown thus existent treatment aims at improving blood flow.

Optimal treatment is still under research and controversies exist but treatment versus non-treatment and early treatment is proved to give better result.

  • Antivirals- Because of common association with viral infection antiviral medication is prescribed by some clinicians.
  • Steroids- Most widely accepted treatment option studies shows improved recovery rate with use of steroid. It can be given orally, or by injection, or Trans tympanic by means of middle ear instillation or round window micro catheter.
  • Vasodilator to improve blood flow or oxygenation to inner ear. Clinical studies shows mixed results. Carbogen inhalation, Papaverin, Histamine, Nicotin and Niacin have been used.
  • Immunosuppressant- Wang et al etanercept in experimental animal study improves hearing result.
  • Ginkgo Biloba
General measures for sudden sensorineural hearing Loss

  • Low salt diet
  • Avoid caffeine, nicotine and alcohol,
  • Avoid noise exposure,
  • Avoid heavy physical activity,
  • Well balanced diet
  • Alpha-lipoic Acid, Antioxidants, Co-enzyme Q10.
  • Zinc, Magnesium, Calcium,
  • Vitamin D, B –Complex, Vitamin C
Hereditary Disorders Causing Sensorineural Hearing Loss
Laboratory investigations
Evaluation of Sudden Sensorineural Hearing Loss (searching for cause)