This document discusses otosclerosis, a disease characterized by abnormal bone remodeling in the otic capsule. It most commonly involves the stapes bone or oval window, resulting in conductive hearing loss. The exact cause is unknown but genetic and autoimmune factors are implicated. Diagnosis involves audiometry demonstrating a conductive hearing loss. Treatment options include hearing aids, medical management to slow progression, and surgical procedures like stapedotomy or stapedectomy to restore hearing.

1. Moderator-Dr.Mohan
Presenter-Dr.Razal

2. 
Definition
 A primary disease of the bony otic capsule
characterized by abnormal removal of mature bone
by osteoclasts and replacement with woven bone of
greater thickness, cellularity and vascularity.
 Clinical Otosclerosis refers to a lesion that involves
the stapes bone or stapidovestibular joint.
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3. 
 Most common site is fissula ante fenestram (anterior
to the stapes foot plate) and also seen in the fossula
post fenestram (area in front and behind oval
window)
 The bone of otic capsule is unique that it exhibits
very low remodeling and contains small regions of
immature cartilaginous tissue called GLOBULI
INTEROSSEI.
 Blue Mantles, an earliest histological alterations of
otic capsule that stain more basophilic.

4. 
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5. 
Epidemiology
Race % incidence of
Caucasian 10%
Asian 5%
African American 1%
Native American 0%

6. 
Epidemiology
 Gender
 Histologic otosclerosis – 1:1 ratio
 Clinical otosclerosis – 2:1 (W:M)
• Increase progression during pregnancy (10%-17%)
• Bilaterality more common (89% vs. 65%)

7. 
Epidemiology
 Age
• 15-45 most common age range of presentation
• Youngest presentation7 years
• Oldest presentation 50s
• 0.6% of individuals <5 years old have foci of
otosclerosis

8. 
Etiology
 The exact cause is unknown but many factors have
been proposed such as:
• Genetic
• Autoimmune
• Infections
• Endocrine (pregnancy)
• Trauma
• Vascular
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9. 
• Hereditary(Autosomal Dominant)
• More common in whites than blacks
• Uncommon in Asian
• Sporadic cases were reported.
• Defects in COL1A1 Gene
• defects in expression of the COLlAl gene has revealed a
significant association between both familial and
sporadic cases
Genetic

10. 
 Type 1 osteogenesis imperfecta shares both clinical
and histologic similarities with otosclerosis.
 Half of all patients with type 1 osteogenesis
imperfecta develop hearing loss that is clinically
indistinguishable from clinical otosclerosis.
 Patients with clinical otosclerosis have blue sclera, a
feature that is found in all patients with type 1
osteogenesis imperfecta.
Osteogenesis Imperfecta

11. 
Infectious (Measles)
 Measles RNA was found in footplate specimens
 Elevated levels of anti measles antibody found in
perilymph from patent undergoing stapedectomy.
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12. 
 a form of autoimmune disease with humoral
autoimmunity to Type II collagen.
 Elevated circulating antibodies to type II collagen are
found in patients of otosclerosis
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Autoimmune

13. 
Pathogenesis
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14. Affects the Otic and labyrinth
Capsule
Enlargement of the Perivascular
Space
Bone Absorption by osteoclast
activity
New Bone deposition by osteocytes
Containing vascular space in center
Lamellar Bone
With time mucoperiostium of
middle ear increases in thickness
and becomes vascular
Reddish Hue through the TM and
disease advances
Involvement of Bony
labyrinth
Involvement of
foot plate.
Cochlear
Otosclerosis
Stapedial
Otosclerosis

15. 
Histologically
Lesion can be divided into
 Active-Spongy structure immature osseous tissue
with numerous dilated vascular channels with
osteoclastic giant cells
 Inactive/Mature
• End stage of bone transformation ,characterized by
solid compact lamellar tissue.
 Siebenmann – first to describe the microscopic appearance

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 The foci demonstrates two phases:
 Early spongiotic phase (otospongiosis)
 Osteocytes, histiocytes, osteoclasts
 Active reabsorption of bone
 Stains blue (blue mantles) on using H&E stain
 Dilated vessels (Schwartze’s sign)
 Late or Sclerotic phase
 Formation of new bone in resorption areas
 New bone is dense and sclerotic
 Stains red on using H&E stain
 Starts in endochondral bone then involves endosteal &
periosteal layers and membranous labyrinth as disease
progress

17. 
 Anterior Focus
 Most common, at fissula ante fenestram
 Posterior Focus
 Lesion spreading from posterior oval window to annular
ligament
 Circumferential
 Lesion flows across the ligament totally obliterating the
annular ligament
 Biscuit type
 Lesion replacing entire footplate, but no involvement of
annular ligament leading to a solid footplate
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Types of Stapedial fixation

18. 
 Obliterative
 Completely obliterates the oval window
 Other areas are:
 Round window, the apex of the cochlea, the cochlear
aqueduct, the semicircular canals, and the stapes
footplate itself
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Types of Stapedial fixation

19. 
Diagnosis
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20. 
 Gradual onset of hearing loss progressing slowly
 In 70% cases hearing loss is bilateral
 Usually becomes apparent around the age of 30
 Loss noticeable when it reaches 25 to 30 dB
 Unilateral loss noticed even later, problem with
localization of sound
 Positive family history
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History

21. 
 SYMPTOMS
 Low modulated voice (BC is more ,patients hears their
own voice.
 Deafness-Mainly Conductive hearing loss,
 Paracussis Willisi-Patient will hear better in noisy
surroundings.
 Tinnitus
 Vertigo
Clinical Features

22. 
Hearing Loss
 Conducting Hearing Loss (CHL)
• Stapedial fixation
• Hearing impairment ranging from 5dB to 60dB.
• Caused primarily by narrowing and impairment of the
annular ligament, at the posterior stapediovestibular joint
space.
 Sensorineural Hearing Loss (SNHL)
• Cochlear otosclerosis
• the sensory and neural elements of the cochlea, such as
hair cells, spiral ganglion cells and stria vascularis, are
intact or their impairment is insufficient to account for the
observed sensorineural hearing impairment.
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23. 
 OTOSCOPY
• SCHWARTZE SIGN:- red blush color occasionally
seen over promontory or anterior to oval window
• Pneumo-otoscopy used to rule out other causes of
CHL such as middle ear serous fluid or small
perforation
TUNING FORK TEST
• Hearing loss progresses form low frequencies to high frequencies
• Rinne Test-Negative
• Weber Test-Laterlized to worst ear.
• ABC-Normal
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Physical Examination

24. 
Pure Tone Audiometry
 CARHART’S NOTCH
 Proposed theory
 Stapes fixation disrupts the normal ossicular resonance (2000
Hz)
 Normal compressional mode of bone conduction is disturbed
because of relative perilymph immobility
 Mechanical artifact
 Reverses with stapes mobilization
 Speech Audiometry
 Normal except in those with cochlear involvement.

26. 
 Tympanometry : As type curve
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Impedance

27. 
 High resolution CT scan
 Shows subtle areas of demineralization
 In case of cochlear involvement it shows “double ring
sign”
 MRI
 Done for patients with unusual presentation
 Detects congenital anomalies of cochlea
 Excludes retrocochlear pathology eg. Acoustic
neuroma
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Radiological Investigations

28. 
Differential Diagnosis
Ossicular discontinuity
Congenital stapes fixation
Malleus head fixation
Paget’s disease
Osteogenesis imperfecta

29. 
TREATMENT
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30. 
Treatment Options
 Hearing aid
 Medical management
 Surgical management-The ‘Gold’ reference standard
of Diagnosis is Surgery
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31. 
Hearing Aid
 Very effective in early stage of disease
 But can be used in advance stage, if:
 Surgery is contraindicated
 Patient refuses the surgery
 In far-advance cases it is required, even after
stapedotomy
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32. 
Medical Management
 Aim is to Stabilize the disease by
 reduction of the osteoclastic bone resorption
increase osteoblastic bone formation
 Inhibits proteolytic enzymes that are cytotoxic to
cochlea.
Slows the progression of sensorineural hearing loss
Not commonly used
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33. 
Tab. Sodium fluoride
Dose : 50 – 75 mg/day OD
Duration : 3 months – 2 years
Function
helps to hasten the maturity of active focus and arrest
further progression of cochlear loss
It has antienzymatic action on proteolytic enzymes
which are cytotoxic to cochlea.
Indications:
 Cochlear otosclerosis
 Active stapedial otosclerosis
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Sodium Fluoride Therapy

34. 
Side effects :
 Fracture of long bones and spine due to fluorosis.
 Nephritis.
 Gastritis
Contraindications:
 Pregnancy & lactation
 Patient with kidney stones / nephritis
 Patient with RA
Sodium Fluoride Therapy

35. 
Surgical Management
 Poorer ear always chosen for surgery
 Done preferably under local anesthesia so patient can
notify surgeon if vertigo occurs during procedure
 Options are:
 Stapedotomy
 Stapedectomy
 Lasers -Lesser complications
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