Hearing

Otosclerosis

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Otosclerosis

  • See Also
  1. Hearing Loss
  2. Sensorineural Hearing Loss
  3. Conductive Hearing Loss
  • Definition
  1. Ankylosis between Stapes footplate and surrounding bone of the inner ear
  • Epidemiology
  1. Most often presents in middle-aged white women
  2. Gender predominance: Twice as common in women
  3. Age at onset: 30-50 years old
  4. Family History is present in 50% of cases
    1. Autosomal Dominant trait, with poor penetrance
  • Pathophysiology
  1. Abnormal bone deposition at base of Stapes (footplate)
  2. Stapes fixed to oval window and unable to vibrate
  • Symptoms
  1. Gradual onset, painless, bilateral Hearing Loss
  2. Tinnitus
  • Signs
  1. Conductive Hearing Loss or mixed Hearing Loss
  2. Hearing Loss usually limited to 50 decibels
    1. See Hearing Impairment Severity Scale
  3. Bilateral involvement is most common
  4. Disproportionately effects low frequencies most commonly
    1. Able to hear voices in noisy environments
  5. Normal Tympanic Membrane appearance
  • Differential Diagnosis
  1. See Conductive Hearing Loss
  • Management
  1. Hearing Aid
  2. Sodium Fluoride
    1. May halt or retard progression
  3. Surgery: Stapedotomy or Stapedectomy
    1. Restore transmission with middle ear prosthesis
    2. Improvement in 95% of patients
  • References
  1. Michels (2019) Am Fam Physician 100(2): 98-108 [PubMed]