2. OBJECTIVES
Definition of otosclerosis
Etiology of otosclerosis
Types of otosclerosis
Clinical features of otosclerosis
Diagnosis of otosclerosis
Medical management of otosclerosis
Surgical management of otosclerosis
3. A primary disease of otic capsule in which
irregular spongy bone replaces the dense
endochondral layer of bony otic capsule,
thereby fixing the footplate of the stapes and
causing conductive hearing loss.
OTOSCLEROSIS
4. HISTORY OF OTOSCLEROSIS
1704 – Valsalva first described stapes
fixation
1857 – Toynbee linked stapes fixation to
hearing loss
1890 – Katz was first to find microscopic
evidence of otosclerosis
1893 – Politzer described the clinical entity
of
“otosclerosis”
5. ETIOLOGY
Exact etiology – not known
1) Idiopathic – Remnants of embryonic
cartilage resting in the otic capsule
may be the etiological factor.
2) Heredity
3) Hormonal – Symptoms increase
during pregnancy and menopause.
4) Van der Hoeve syndrome –
Osteogenesis imperfecta,
otosclerosis, Blue sclera
6. 5) Associated with Paget’s disease.
6) Enzymatic theory – (Latest)
Imbalance in trypsin / antitrypsin in
the inner ear fluid initiates
otosclerosis.
7) Metabolic and immune disorders.
8) Anatomical and Histological
anomalies of temporal bone.
9) Recent – Relationship between prior
infection with measles virus and
later development of otosclerosis.
7. INCIDENCE
0.5-1% of total population
Female: Male (2:1)
20 – 30 years of age
Common in white races, but common in
Indians and low in chinese and
Japanese.
Usually bilateral (85%)
8. TYPES
1) Stapedial otosclerosis : (common)
Sites – 1) Fissula ante fenestrum
2) Fissula post fenestrum
3) Circumferential
4) Biscuit type or rice grain
type with delineated
margins
5) Obliterative type
9.
10. 2) Cochlear otosclerosis:
Involves the region of round window
and labyrinth in the absence of
stapes
fixation
Sensorineural hearing loss due to
liberation of toxic materials from
abnormal bone into inner ear.
11. 3) Malignant otosclerosis
Severe type of cochlear otosclerosis
Starts early in life and progresses
rapidly.
4) Combined otosclerosis – mixed
hearing loss.
5) Histological otosclerosis:
9 – 12% cases,
No clinical features but histologically
the focus is present.
12. PATHOLOGY
Grossly – appears as chalky white or yellow
focus (inactive) or red in colour due to
increased vascularity (active)
Microscopically –
1) In immature (active) foci, there are numerous
marrow and vascular spaces with plenty of
osteoblasts and osteoclasts which stains blue on
H&E stain. (Blue mantle)
2) In mature (inactive) foci, there is less vascular
spaces with lot of fibrous tissue which stains red
on H&E stain
14. SIGNS
1) TM : normal and mobile
2) Schwartze sign or Flamingo pink
appearance
3) TFT : Conductive hearing loss
4) PTA : Carhart’s notch
5) Impedance Audiometry – Type As curve
18. Natural History of
Otosclerosis
90% of all cases are never clinically
apparent
Foci begins in childhood
Most commonly becomes symptomatic in
the 3rd and 4th decades
After clinical presentation
◦ Conductive hearing loss progressive
◦ Periods of quiescence and deterioration
◦ Worsening tinnitus
◦ Associated SNHL (rarely purely SN)
19. Tab. Sodium fluoride
Dose : 50 – 75 mg/day,
Duration : 3 months – 2 years
Function
1) helps to hasten the maturity of active focus
and arrest further progression of cochlear
loss
2) It has antienzymatic action on proteolytic
enzymes which are cytotoxic to cochlea.
MEDICAL TREATMENT
20. Indications:
Cochlear otosclerosis
Active stapedial otosclerosis
Side effects :
Fracture of long bones and spine due to
fluorosis.
Nephritis.
Gastritis
Contraindications:
Pregnancy & lactation
Patient with kidney stones / nephritis
21. History of Stapes Surgery
Samuel Rosen
◦ 1953 – first
suggested
mobilization of
the stapes
Immediate
improved hearing
Re-fixation
22. History of Stapes Surgery
Julius Lempert
◦ Popularized the single staged
fenestration
in the horizontal canal with a
tissue graft covering
◦ >2% profound SNHL
◦ Rarely complete closure of the
ABG
John House
◦ Further refined the procedure
Popularized blue lining the
horizontal canal
23. History of Stapes Surgery
John Shea
◦ 1956 – first to
perform
stapedectomy
Oval window vein
graft
Nylon prosthesis
from incus to oval
window
24. SURGICAL TREATMENT
1) Lempert’s fenestration operation
(1938)
2) Rosen’s stapes mobilisation (1953)
3) Shea’s stapedectomy (1958)
4) Stapedotomy – small fenestra
stapedectomy. (Laser can be used)
Hearing Aids
27. Contraindications:
1. Only hearing ear
2. Otitis externa, CSOM
3. Cochlear otosclerosis
4. Young children / old age
5. Athletes, drivers, frequent air
travelers, those who works in
noisy environment.
6. General medical illness
7. Pregnancy.
28. Complications
1. Perforation of ear drum
2. Total SN loss
3. Chronic vertigo
4. Facial nerve paralysis
5. Perilymph fistula
6. Granuloma.
