Transcript OTOSCLEROSIS DR. SUDEEP K.C.  ANATOMY REVIEW:  OTIC LABYRINTH OR MEMBRANOUS LABYRINTH OR ENDOLYMPHATIC.  PERIOTIC LABYRINTH OR PERILYMPHATIC LABYRINTH – SURROUNDS THE OTIC LABYRINTH.

OTOSCLEROSIS
DR. SUDEEP K.C.
 ANATOMY REVIEW:
 OTIC LABYRINTH OR MEMBRANOUS LABYRINTH OR
ENDOLYMPHATIC.
 PERIOTIC LABYRINTH OR PERILYMPHATIC LABYRINTH
– SURROUNDS THE OTIC LABYRINTH & IS FILLED WITH
PERILYMPH.
 OTIC CAPSULE – IT IS THE BONY LABYRINTH GOT
THREE LAYERS
ENDOSTEAL-THE INNERMOST LAYER. LINES THE BONY
LABYRINTH
 ENCHODRAL- DEVELOPS FROM THE CARTILAGE & LATER
OSSIFIES INTO BONE.
 PERIOSTEAL –COVERS THE BONY LABYRINTH.

AETIOLOGY
 IDIOPATHIC SOME FACTS HAVE BEEN
DOCUMENTED
ANATOMICAL BASIS –BONY LABYRINTH IS MADE OF
ENCHONDRAL BONE WHICH IS SUBJECT TO LITTLE
CHANGE IN LIFE. BUT SOMETIMES , IN THIS HARD BONE
THERE ARE AREAS OF CARTILAGE RESTS WHICH, DUE
TO CERTAIN NON-SPECIFIC FACTORS, ARE ACTIVATED
TO FORM NEW SPONGY BONE .
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HERIDITY- 50% OF OTOSCLEROTICS HAVE POSITIVE
FAMILY HISTORY
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RACE – WHITE RACE ARE AFFECTED MORE THAN
NEGROS. IT IS COMMON IN INDIANS BUT RARE AMONG
CHINESE & JAPANESE
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SEX- FEMALE 2 TIMES THAN MALE
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AGE OF ONSET- DEFNESS USUALLY STARTS BETWEEN
20-30 YRS
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EFFECT OF OTHER FACTORS- DEAFNESS DUE TO
OTOSCLEROSIS MAY BE INITIATED OR MADE WORSE BY
PREGNANCY , MENOPAUSE, ACCIDENT OR SURGERY
Types of Otosclerosis
1)Stapedial otosclerosis:
It cause the fixation of stapes result in conductive
deafness . lesion starts just in front of oval window in
an area called ‘fissula ante fenestram’. This is the site
of predilection(ant. Focus).
2)Cochlear Otosclerosis:
It involves region of round window or other area in
otic capsule, and may cause sensorineural hearing
loss .
3)Histologic otosclerosis:
This type of otosclerosis remains asymptomatic and
cause neither conductive nor sensorineural hearing
loss.
Pathology:
Grossly lesion appears chalky white, greyish or yellow .
sometimes red in colour due to increased vascularity.
Microscopically, there are numerous marrow and
vascular spaces with plenty of osteoblast and
osteoclasts that stains blue.
SYMPTOMS:
1)Hearing loss:
Usually starts in twenties . Hearing loss is painless
and progressive with insidious onset . often it is
bilateral conductive type.
2)Paracusis willisi:
They hear better in noisy than quiet surroundings .
This is because a normal person will raise his voice in
noisy surroundings.
3)Tinnitus : It is more seen in cochlear otosclerosis
and in active lesion.
4)Vertigo: uncommon
5) Speech: monotonous well modulated soft speech.
SIGNS:
a)TM is quite normal and mobile .Sometimes,a
reddish hue is seen on the promontory through
tympanic membrane(Schwartze sign).Indicative of
active focus with increased vascularity.
b)Eustachian tube function is normal.
c)Tuning fork test show negative Rinne .
d)Weber test will be lateralised to the ear with greater
conductive loss.
d)Pure tone audiometry shows loss of air conduction
more for lower frequencies.
Bone conduction is normal . In some cases there is a
dip in bone conduction curve maximum at 2000hz
and is called the Carhart’s notch.
e) Stapedial reflex becomes absent when stapes is
fixed.
TREATMENT:
a)Medical : sodium fluoride has been tried to hasten
the maturity of active focus and arrest further
cochlear loss.
b)Surgical: Stapedectomy with prosthesis replacement
is the treatment of choice.

laser STAMP
Selection of patients for stapes surgery:
Hearing threshold should be 30db or more.
Average air bone gap is 15 db with Rinne negative.
Laser STAMP (Laser Stapedotomy
Minus Prosthesis)
 In 1995, Dr. Silverstein developed a new technique called
the Laser STAMP. The laser is used to free the frozen stapes
bone in patients with minimal otosclerosis, preserving most
of the patient's normal stapes bone. This restores the
patient's hearing, without using a prosthesis. The
advantages of preserving most of the patients' stapes
include reduced sensitivity to noise, decreased incidence of
noise damage to the ear, and reduced chance of trauma to
the inner ear from changes in pressure during flying or
diving.
Contraindications to stapes surgery:
1. The only hearing ear.
2. Associated meniere’s disease.
3. Young children.
4. Professional athletes , high construction workers,
frequent air travellers.
5. Those who work in noisy environment.
C) Hearing aid:
DIFFERENTIAL DIAGNOSIS
 SHOULD BE DIFFERNTIATED FROM OTHER
CAUSES OF CONDUCTIVE DEAFNESS
PARTICULARLY –
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SEROUS OTITIS MEDIA
ADHESIVE OTITIS MEDIA
TYMPANOSCLEROSIS
ATTIC FIXATION OF HEAD OF MALLEUS
OSSICULAR DISCONTINUITY
CONGENITAL STAPES FIXATION