OTOSCLEROSIS

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2. OTOSCLEROSIS

3. DEFINITION A primary disease of the otic capsule characterized pathologically by abnormal resorption and deposition of bone

4. HISTOPATHOLOGY Resorption of bone by osteocytes Formation of new vascular spongy bone Formation of dense sclerotic bone

5. AREAS OF PREDILECTION Fissula ante fenestram (80% to 90%)

6. OTHER AREAS Round window, the apex of the cochlea, the cochlear aqueduct, the semicircular canals, and the stapes footplate itself

7. COCHLEAR INVOLVEMENT

8. ETIOLOGY Unknown cause Positive family history in about 60% Inherited by autosomal dominant transmission with incomplete penetration (60%) Persistent measles virus infection Detection of measles virus RNA in the affected bone Detection of measles virus-specific antibodies in the perilymph

9. PHYSIOLOGY Conductive HL: due to fixation of the stapedial footplate Mixed HL: due to Liberation of toxic metabolites into the inner ear Vascular compromise from sclerosis and narrowing of vascular channels Direct extension of lesions into the inner ear Cochlear otosclerosis

11. CLINICAL PRESENTATION Hearing loss of gradual onset at 15 - 45 years Slowly progressive course 70% are bilateral Accelerates with pregnancy (30-40%) Tinnitus Paracusis Willisii Change of the speech pattern Vestibular symptoms

12. PHYSICAL EXAMINATION Normal tympanic membrane Schwartze sign (Flamingo flush)

13. PHYSICAL EXAMINATION Normal tympanic membrane Schwartze sign (Flamingo flush) Tuning fork tests

14. PURE TONE AUDIO

15. CARHART�S NOTCH Decrease in bone conduction thresholds 5 dB at 500 Hz 10 dB at 1000 Hz 15 dB at 2000 Hz 5 dB at 4000 Hz Explanation is not known Reverses following successful surgery

16. AUDIOMETRY Pure tone audiogram Speech discrimination

17. AUDIOMETRY Pure tone audiogram Speech discrimination Impedence & tympanometry

18. CT SCAN

19. COCHLEAR OTOSCLEROSIS Isolated pure sensorineural hearing loss without a conductive component

20. CRITERIA FOR DIAGNOSIS OF COCHLEAR OTOSCLEROSIS Progressive pure cochlear loss beginning at the usual age of onset for otosclerosis Unilateral conductive hearing loss consistent with otosclerosis and bilateral symmetric SNHL Positive Schwartze�s sign Positive family history Excellent discrimination Stapedial reflex demonstrating the �on-off effect� CT: demineralization of the cochlea

21. DIFFERENTIAL DIAGNOSIS Congenital fixation of the stapes Middle ear effusion Chronic OM and ossicular discontinuity Tympanosclerosis Malleus head fixation Systemic diseases

22. SYSTEMIC DISEASES Osteogenesis imperfecta Stapes fixation Blue sclera Fractures

23. SYSTEMIC DISEASES Osteogenesis imperfecta Stapes fixation Blue sclera Fractures Pagets disease Crowding in epitympanum Elevated alkaline phosphatase Skeletal bone involvement

24. TREATMENT Observation Hearing aid Medical treatment Surgical treatment

25. OBSERVATION

26. INDICATIONS OF OBSERVATION Unilateral Mild CHL Young age

27. HEARING AID

28. INDICATIONS OF HEARING AID Refuse surgery Poor surgical candidate Following improvement of CHL

29. MEDICAL TREATMENT

30. AIM OF MEDICAL TREATMENT Stabilize the disease by reduction of the osteoclastic bone resorption and increase osteoblastic bone formation

31. MEDICAL MANAGEMENT Sodium fluoride: 50-75 mg /day/2years followed by 25 mg for life Vitamin D Calcium carbonate

32. INDICATIONS Cochlear otosclerosis Patients with confirmed otosclerosis but having progressive SNHL disproportionate to age

33. CONTRAINDICATIONS Chronic nephritis Rheumatoid arthritis Pregnancy and lactation Children

34. SURGICAL TREATMENT

35. PATIENT SELECTION FOR SURGICAL TREATMENT Socially unacceptable conductive or mixed hearing loss Good speech discrimination Age Lifestyle and occupation

36. ABSOLUTE CONTRAINDICATION OF SURGERY The better or the only functioning ear

37. OTHER CONTRAINDICATIONS ? Patients experience frequent changes in barometric pressure �Malignant� otosclerosis Endolymphatic hydrops TM perforation Infections

38. STAPES SURGERY

39. STAPEDECTOMY Results probably are the best More traumatic to the inner ear Increased post-op vestibular symptoms Higher incidence of postoperative SNHL The operation is unavoidable in: Comminuted fracture of the footplate Revision surgery

40. STAPEDOTOMY Equal or better results with less vestibulocochlear side effects

41. COMPARISON

42. STAMP Preservation of the stapedius tendon Reduction in hyperacusis Reduction in risk for long-term postoperative inner ear injuries No prosthesis complications Very difficult technique

43. SURGICAL PROCEDURE

44. The Incision

50. STAPEDOTOMY

51. LASER STAPEDOTMY

52. STAMP

53. OPERATIVE PROBLEMS & COMPLICATIONS

54. TM PERFORATION Proceed and then repair

55. CHORDA TYMPANI INJURY 30% of cases Metallic taste Symptoms usually resolves in 3-4 months More symptoms if bilateral

56. OBTRUSIVE FACIAL NERVE 0.5 % Stapedotomy is usually possible

58. BLEEDING Mucosal trauma Active phase Persistent stapedial artery

59. Persistent stapedial artery

62. ROUND WINDOW OTOSCLEROSIS About 1% complete (Shuknecht) If complete: Abandon surgery If incomplete or not sure: Do not remove bone and proceed

63. OBLITERATIVE OTOSCLEROSIS OF THE OVAL WINDOW A total stapedectomy is contraindicated because of high risk of surgically induced SNHL

64. INCUS PROBLEMS Subluxation: Proceed Dislocation: Remove incus & use a malleus-grip prosthesis

65. FLOATING FOOTPLATE May be avoided if control holes are used or by using laser fenestration

66. FLOATING FOOTPLATE May be extracted by needles/hooks with hole inferior to the oval window

67. FLOATING FOOTPLATE In many cases should be left and surgery is completed with unpredictable results or use laser fenestration

68. MALLEUS ANKYLOSIS About 0.5% May be congenital or acquired Causes about 15-20 dB CHL Remove malleus head and the incus and use malleus grip prosthesis

69. CSF GUSHER Due to fundal defect of IAM or widened cochlear aqueduct Introduce spinal catheter and proceed Or Pack with fascia and gauze for 4-5 days with delayed reconstruction that avoid reopening the fenestra

70. PERILYMPH FISTULA Primary or secondary

71. PREVENTION OF PERILYMPH FISTULA Stapedectomy < stapedotomy Oval window seal No fat or gel-foam for seal Prohibit nose blowing, flying, diving, & lifting heavy objects postoperatively

72. DIAGNOSIS OF PERILYMPH FISTULA Drop or fluctuation in hearing Vertigo & tinnitus Audiometry ENG Fistula test Radiology

75. TREATMENT Surgical closure

76. REPARATIVE GRANULOMA Granuloma formation around the prosthesis and incus 1-5% Gradual deterioration 5-15 days postoperativly Vertigo, tinnitus and deafness Otoscopy: reddish discoloration of the posterior TM

77. REPARATIVE GRANULOMA Treatment is by emergency tympanotomy and excision

78. SNHL 0.2-10% Serous labyrinthitis - high frequencies Surgical trauma

79. PERSISTENCE OR RECURRENCE OF CHL Prosthesis malfunction Fibrous adhesion Incus erosion

83. PERSISTENCE OR RECURRENCE OF CHL Prosthesis malfunction Fibrous adhesion Incus erosion Missed pathology: e.g. malleus fixation, round window otosclerosis Otosclerosis regrowth

84. RARE COMPLICATIONS Facial paralysis Acute otitis media Cholesteatoma

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