Otosclerosis is defined as hereditary localized disease of bone derived from the otic capsule characterized by alternating phases of bone formation and resorption
The mature lamellar bone is resorbed and replaced by an immature woven bone of greater thickness, cellularity and vascularity
First described by Politzer in 1893
Types of Otosclerosis
Stapedial
Cochlear: Round window and Promontory
Mixed: Stapedial + cochlear
Malignant: Rapidly progressing cochlear lesion with severe sensori-neural deafness
Types of Stapedial otosclerosis
1. Anterior focus (commonest): 2 mm anterior to oval
window , fissula ante fenestrum, more unstable
2. Posterior focus: 2 mm behind oval window
3. Circumferential: involves footplate margin only
4. Biscuit type: footplate involved, margin is free
5. Obliterative : Obliterates the oval window completely
2. Definition
• Hereditary localized disease of bone derived from the
otic capsule characterized by alternating phases of
bone formation and resorption
• The mature lamellar bone is resorbed and replaced
by an immature woven bone of greater thickness,
cellularity and vascularity
• First described by Politzer in 1893
3. •New bone
–Spongy and more vascular in otospongiosis
(Active Stage)
– Thicker and more denser in otosclerosis
(Inactive Stage)
4. Epidemiology
• Exact etiology - unknown
• Factors:
– Genetic: Autosomal dominant with variable penetrance
– Race: Common in white races & Indians
– Sex : Female : Male = 2 : 1
– Age : Common in 20 - 40 years
– Hormonal influence: Rapidly advances in pregnancy,
menopause , stress (trauma, surgery)
– Viral : Measles
5. Van der Hoeve syndrome
Otosclerosis + osteogenesis imperfecta + blue sclera
6. Types of Otosclerosis
• Stapedial
• Cochlear
− Round window and Promontory
• Mixed
− Stapedial + cochlear
• Malignant
− Rapidly progressing cochlear lesion with severe sensori-
neural deafness
7. Types of Stapedial Otosclerosis
1. Anterior focus (commonest): 2 mm anterior to oval
window , fissula ante fenestrum, more unstable
2. Posterior focus: 2 mm behind oval window
3. Circumferential: involves footplate margin only
4. Biscuit type: footplate involved, margin is free
5. Obliterative : Obliterates the oval window completely
9. Symptoms of Otosclerosis contd….
4. Paracusis of Willis ( Paracusis Willisii): Patient hears better in
noisy surroundings (people increase their voice intensity so
that patient’s speech discrimination becomes better)
10. • Otoscopy
– Tympanic Membrane normal in most cases
– Schwartze sign / Flamingo pink blush
• Pinkish colour over promontory
• Seen in otospongiosis (2 - 10 % cases)
11. Tuning Fork Tests
Rinne Weber A.B.C.
Stapedial Negative
(BC > AC)
Lateralizes to
Deaf ear
Normal
Cochlear Positive
(AC > BC)
Lateralizes to
Better ear
Decreased
Mixed Negative
(BC > AC)
Lateralizes to
Better ear
Decreased
12. Gelle & Bing Tests
• Vibrating tuning fork placed over mastoid
– External auditory canal is blocked in Bing test
– E.A.C. pressure increased by Siegalization in Gelle
Bing Gelle
Otosclerosis No change No change
Normal / SNHL Intensity
Increases
Intensity
Decreases
13. Investigations
A) Pure Tone audiometry (PTA)
– Low frequency conductive deafness
– Carhart’s notch in bone conduction at 2 KHz
14. • Proposed theories for Carhart’s notch
– Stapes fixation disrupts normal ossicular
resonance (2000 Hz)
– Normal compression mode of bone conduction is
disturbed because of relative perilymph immobility
• Carhart’s notch reverses with stapes surgery
15. B) Speech Audiometry
– Speech Discrimination Score : (maximum score
achieved) is almost 100 %
– Speech Reception Threshold (intensity at which 50
% words are heard) : increased by the amount of
conductive hearing loss
16. C) Impedance Audiometry
– As curve seen in 40 % cases
of otosclerosis (Normal middle
ear pressure but decreased
middle ear compliance)
– Others have A curve
• Stapedial reflex : absent
21. History of stapes surgery
• Stapes mobilization: Kessel (1880), Rosen (1952)
• Lateral semicircular canal fenestration: Holmgren
(1923), Lempert (1938)
• Stapedectomy: Jack (1893), John Shea Jr. (1956)
• Stapedotomy: Myers, 1970
• Laser Stapedotomy: Perkins, 1980
22. Inclusion criteria for stapes surgery
• Pure Tone Average between 30 - 60 dB
• Air bone gap > 15 dB
• Speech discrimination score > 60 %
• Absence of sensorineural deafness
23. Contraindications for surgery
• Only hearing ear
• Meniere’s disease
• Otitis media
• Otitis externa
• Extremes of age
• Pregnancy
• Professions: divers, high construction workers,
frequent travelers, noisy surroundings
53. Medical Treatment
• Sodium Fluoride given in cochlear otosclerosis &
active focus of otospongiosis (Schwartze sign)
• Acts by:
a. Decreases bone resorption
b. Increases bone formation
c. Prevents enzymatic damage to cochlea
• 20 mg orally, thrice daily for 3 - 6 months
