Otosclerosis is the overgrowth of the spongy bones in the bones of the middle ear leading to the fixation of the bones causing conductive hearing loss in patient. This lecture includes its pathophysiology, causes, risk factors, symptoms and treatment

1. OTOSCLEROSIS
By :
Miss Saili Gaude
Principal
Shivam College of Nursing, Amirgadh

2. Definition
 Otosclerosis – abnormal
hardening of the ear bone. In this
condition the spongy bone
overgrow preventing movement
of stapes bone over the oval
window resulting in conductive
deafness.

3. Etiology
 Unknown
 Family history
 More common in women than men
 History of measles infection
 Bone disorders
 Endocrine (pregnancy)
 Infections
 Trauma
 Autoimmune

4. TYPES
HISTOLOGICAL OTOSCLEROSIS
• The type of otosclerosis which does not produce any symptoms
and may be identified on post mortem . It is discovered by
sectioning of the temporal bone during autopsy
CLINICAL OTOSCLEROSIS
• Refers to a lesion that involves the stapes bone or stapes bone
or stapediovestibular joint and consequently is clinically
manifested by a conductive hearing impairment.

6. TYPES OF CLINICAL OTOSCLEROSIS
 1) Stapedial otosclerosis
 2) Cochlear otosclerosis
 3) Mixed otosclerosis

7. 1. STAPEDIAL OTOSCLEROSIS
 The otosclerosis focus may produce ankylosis of the membraneous labyrinth.
 Here the stapes hardens
 There is fixation of stapes resulting in immobilization of the bone. Thus there is
disruption of the vibrations from tympanic to cochlea.
 The hardening occurs most commonly at “Fistula ante fenestrum” which is a small cleft
present in front of the oval window.
 Types :

8. 2. COCHLEAR OTOSCLEROSIS
 Defined as otosclerosis located in the
otic capsule involving the cochclear
endosteum and causing sensorineural
hearing loss or mixed type of hearing
loss.
 It involves the region of round window
and labyrinth in the absence of stapes.
 Sensorineural hearing loss occurs due
to liberation of toxic materials from
abnormal bone into inner ear.
 It is very rare
 Positive schwartze sign and positive
family history

9. 3. MIXED OTOSCLEROSIS
 Otosclerosis causes both fixation of the stapes as well as in involvement of the
labyrinth so that there are mixed hearing loss.

10. Clinical manifestations
 Hearing loss – usually starts in one
ear and than progresses to the other.
Occurs gradually
 Inability to hear low pitched sounds
 Cannot hear whispers
 Tinnitus- ringing sensation in the ears

11. Patholphysiology
Due to
any
etiologi
cal
factors
1
Normal
bone is
replaced
by
spongy
bone
2 Spongy
bone
immobili
zes the
foot
plate of
normally
mobile
stapes
3 Disrupti
on of
vibration
s from
tympani
c
membra
ne to
cochlea
4 Hearing
loss
5

12. PATHOGENESISN
 Divided in 2 phases:
 1) EARLY SPONGIOTIC PHASEA- In this there is active reabsorption of bone. Dilation
of vessels is seen. Schwartz’s sign is present. Bone turnover is increased and there is
increased vascularity
 2) LATE OR SCLEROTIC PHASE- formation of new bone in resorption areas. New
bone is dense and sclerotic. Dense mineralization occurs.

13. DIAGNOSTIC EVALUATION
 TUNING FORK EVALUATION- rinne’s test is negative while in severe condition
Webr’s test may be positive with lateralization of sound
 AUDIOMETRY -pure tone audiometry reveals conduction hearing loss.
 TYMPANOMETRY- normal in early conditions but with severity , a stiffness or
flattening curve may be observed, indicating low compliance of the ossicular chain and
tympanic membrane.
 CT Scan- otosclerosis is typically diagnosed using high resolution computed
tomography of the temporal bones. The fenestral foci, which are located in the area
anterior to the oval window, can be found in more than 80% cases
 SCHWARTZE SIGN: the schwartze sign which is also known as flamingo flush sign or
rising sun sign, is a characteristically reddish discolouration of the promontory due to
the characteristic otosclerotic lesion

14. AUDIOMETRY

15. TUNING FORK EVALUATION

16. TYMPANOMETRY

17. MEDICAL MANAGEMENT
 Fluoride
 Vitamin D
 Calcium
Mechanism of action is controversial but usually helps by slowing the progression of
otosclerosis
Patient may require hearing aid to amplify sound

18. GENERAL MEASURES
 Avoidance of noisy environment
 Side lying position
 Continuous applications of medications
 High protein diet

19. Surgical management
 Stapedotomy or stapedectomy with prosthesis placement.
 1. Stapedectomy : removal of portion of the sclerotic stapes footplate of stapes or
complete removal of the stapes and the implant with prosthesis to maintain suitable
conduction.
 2. Stapedotomy : modern surgery called stapedotomy is performed by drilling a small
hole in the stapes footplate with micro drill or laser and then insertion of a piston like
prosthesis

20. STAPEDECTOMY

21. STAPEDOTOMY

22. Complications
 Sensorineural hearing loss
 Facial palsies
 Tinnitus