11. Otosclerosis, tympanosclerosis

• Otosclerosis
  • Abnormal bone growth of the bony labyrinth
  • The stapes becomes increasingly fixated to the oval window -> progressive conductive HL
  • Can also affect cochlea
  • Epidemiology
    • Whites
    • Females
    • Adults
  • 50% autosomal dominant, 50% sporadically
  • Diagnosis
    • Decreased air conduction on pure tone
    • Carhart notch on audiogram
    • Normal otoscopy
  • Treatment
    • Stapes replaced by prosthesis – stapedotomy

• Tympanosclerosis
  • Scarring of tympanic membrane and cavity due to recurrent otitis externa or media
  • Asymptomatic or conductive hearing loss due to fixation of ossicles
  • White calcified plaques on otoscopy
  • Myringosclerosis – only tympanic membrane
    • Rarely symptoms
  • Treatment
    • Surgical removal of sclerosis
      • Usually recurs