Otosclerosis

1. Otosclerosis Department of Otorhinolaryngoglogy the 2nd Hospital affliatted to Medical college Zhejiang University Xu Yaping

2. Introduction • Otosclerosis 1. Primary metabolic bone disease of the otic capsuleand ossicles 2. Results in fixation of the ossicles and conductivehearing loss 3. May have sensorineural component if the cochlea isinvolved 􀂄Genetically mediated via autosomal dominant transmissionwith incomplete penetrance (40%)and variable expressivity.

3. History of Otosclerosis and Stapes surgery 􀂄 1704 – Valsalva first described stapes fixation 􀂄 1857 – Toynbee linked stapes fixation tohearing loss 􀂄 1890 – Katz was first to find microscopicevidence of otosclerosis 􀂄 1893 – Politzer described the clinical entity of “otosclerosis” 􀂄 1890 – Bacon describes medical therapy for the condition, and supports the common view that “surgery should not be considered for a moment.“

4. Epidemiology • 10% overall prevalence of histologic otosclerosis • 1% overall prevalence of clinically significantotosclerosis • Clinical otosclerosis ––2:1 (W:M) • Possible progression during pregnancy (10%-17%) • Bilaterality more common (89% vs. 65%) • 15-45 most common age range of presentation, increases with age

5. Pathophysiology • Osseous dyscrasia • Resorption and formation of new bone • Limited to the temporal bone and ossicles • Inciting event unknown, many theories: Hereditary, endocrine, metabolic, infectious, vascular, autoimmune,hormonal .

6. Most common sites of involvement • 􀂄Fissula antefenestrum • 􀂄Round window niche (30%-50% of cases) • 􀂄Anterior wall of the IAC

7. Histology otosclerosis has two main forms: • an early of spongiotic phase (otospongiosis) multiple active cell groups including osteocytes, osteoblasts, and histiocytes. 2. a late or sclerotic phase: dense sclerotic bone forms

8. Non-clinical foci of otosclerosis

10. Bipolar involvement of the footplate

11. Round Window

12. Diagnosisof Otosclerosis 􀂄1. Most common presentation 􀂄Women age 20 - 30 􀂄2. Conductive or Mixed hearing loss slowly progressive,bilateral (80%),asymmetric 􀂄Tinnitus (75%)

13. a complete history: • Age of onset of hearing loss • Progression • Laterality • Associated symptoms • Dizziness • Otalgia • Otorrhea • Tinnitus

14. Family history 􀂄2/3 have a significant family history 􀂄Particularly helpful in patients with severe or profound mixed hearing loss • Prior otologic surgery • History of ear infections • Vestibular symptoms 􀂄25% 􀂄Most commonly dysequilibrium 􀂄Occasionally attacks of vertigo with rotatory nystagmus

15. Physical Exam • Otomicroscopy Most helpful in ruling out other disorders 􀂄Middle ear effusions 􀂄Tympanosclerosis 􀂄Tympanic membrane perforations 􀂄Cholesteatoma or retraction pockets 􀂄Superior semicircular canal dehiscence Schwartze’’s signs( by Schwartze in 1873) 􀂄Red hue behind the tympanic membrane (in oval window niche area) 􀂄10% of cases • Pneumatic otoscopy 􀂄Distinguish from malleus fixation

16. Tuning forks 􀂄1. Hearing loss progresses form low frequencies to high frequencies 􀂄 2. 256, 512, and 1024 Hz TF should be used 3. Rinne 􀂄256 Hz ––negative test indicates at least a 20 dB ABG 􀂄512 Hz ––negative test indicates at least a 25 dB ABG (air-bone gaps)

17. Differential Diagnosis • Ossicular discontinuity:A.conductive loss of 60 db B. type Ad tympanogram 2.Congenital stapes fixation:A.25% incidence of other congenital anomalies B. non-progressive CHL 3.Malleus head fixation: when congenital, associated with other stigmata (aural atresia). 4.Paget’’s disease: diffuse involvement of the bony skeleton 5.Osteogenesis imperfecta: presence of blue sclera 6.Superior semicircular canal dehiscence: vertigo or eye movements with loud noise

18. Audiometry 􀂄Tympanometry 􀂄Impedance testing Acoustic reflexes 􀂄Pure tones

19. As (s-stiffness curve) tympanogram is characteristic of advanced otosclerosis

20. Acoustic Reflexes • Otosclerosis has a predictable pattern of abnormal reflexes over time • Reduced reflex amplitude • Elevation of ipsilateral thresholds • Elevation of contralateral thresholds • Absence of reflexes

21. Pure Tone Audiometry • Most useful audiometric test for otosclerosis 􀂄Characterizes the severity of disease 􀂄Frequency specific • Carhart’’s notch 􀂄Hallmark audiologicsign of otosclerosis 􀂄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

22. early stage middle stage

23. late stage

24. Imaging • Computed tomography (CT) of the temporal bone 􀂄Proponents of CT for evaluation of otosclerosis Pre-op • Characterize the extent of otosclerosis • Severe or profound mixed hearing loss • Evaluate for enlarge cochlear aqueduct Post-op • Recurrent CHL • Re-obliteration vs. prosthesis dislocation • Vertigo

26. Managementoptions • Medical: Sodium Fluoride,Bisphosphonates,Vitamin D and Calcium • Amplification:Non-surgical candidates-wearing hearing aids. • Surgery: Stapedectomy vs. Stapedotomy • Combinations

27. Surgery • Best surgical candidate • Previously un-operated ear • Good health • Unacceptable ABG • 25 to 40 dB • Negative Rinne test • Excellent discrimination • Desire for surgery

28. Tympanosclerosis • Definition: a whitish "plaque" of the TM. • Pathology: submucosal hyaline degeneration in the TM and middle ear mucosa. • extensive involvement of the TM and ossicle amy result in conductive hearing loss.(air-bone gap >40dB) • medical therapy and pressure equalization tubes (PETs) do not prevent progression of disease.

29. The end, thank you!