Otosclerosis

1. Otosclerosis Otosclerosis
Mr. Ashok bishnoiMr. Ashok bishnoi
Lecturer JINRLecturer JINR

2. Definition:-Definition:-

It is metabolic bone disease of It is metabolic bone disease of
the ossicles in which normal the ossicles in which normal
bone is replaced by abnormal bone is replaced by abnormal
“spongy bone” causing fixation “spongy bone” causing fixation
of the stapes bone.of the stapes bone.

3. Incidence:-Incidence:-

Age Age

The incidence of otosclerosis increases with The incidence of otosclerosis increases with
age. age.

The most common age group presenting with The most common age group presenting with
hearing loss from otosclerosis is 15-45 years, hearing loss from otosclerosis is 15-45 years,

4. Etiology Etiology
. Unknown. Unknown
Risk factors-Risk factors-

Family historyFamily history

Metabolic, enzyme abnormalatyMetabolic, enzyme abnormalaty

Infectious, virus was identified in the Infectious, virus was identified in the
lesionlesion

AutoimmuneAutoimmune, ,

5. PathophysiologyPathophysiology
Due to etiological factorsDue to etiological factors
Distruction of normal bone release enzymesDistruction of normal bone release enzymes
Vestibular & cochlear function impairmentVestibular & cochlear function impairment
CalcificationCalcification(deposition of calcium in the tissue)(deposition of calcium in the tissue)
Fixation of stapes boneFixation of stapes bone
Immobilization of footplate in oval windowImmobilization of footplate in oval window

6. Clinical manifestation:-Clinical manifestation:-

Hearing lossHearing loss

Schwartz’s sign Schwartz’s sign (Normal appearing tympanic membrane (Normal appearing tympanic membrane
(a pink colour is noted through the tympanic membrane)(a pink colour is noted through the tympanic membrane)

Absent acoustic reflexAbsent acoustic reflex

TinitusTinitus

Quiet well modulated voiceQuiet well modulated voice

7. Diagnostic evaluation:-Diagnostic evaluation:-

HistoryHistory

Physical examinationPhysical examination

Schwartze sign is observed in 10% of Schwartze sign is observed in 10% of
patients). patients).

Rinne test: negative Rinne test: negative

Weber test: Weber test:
AudiometryAudiometry
Otoscopic examinationOtoscopic examination

8. Image study Image study

CT can characterize the extent of CT can characterize the extent of
the otosclerotic focus at the oval the otosclerotic focus at the oval
window window

CT scan can exclude capsular CT scan can exclude capsular
involvement when patients have involvement when patients have
significant mixed hearing loss significant mixed hearing loss

An enlarged cochlear aqueduct An enlarged cochlear aqueduct
may be seen which potential may be seen which potential
causes perilymph gusher during causes perilymph gusher during
footplate fenestration or removal. footplate fenestration or removal.

It reveal normal round window and It reveal normal round window and
normal mastoid pneumatization.normal mastoid pneumatization.

9. Differential diagnosisDifferential diagnosis

Ossicular discontinuityOssicular discontinuity

conductive loss of 60 db usually without conductive loss of 60 db usually without
sensorineural componentsensorineural component

flaccid tympanic membrane on pneumatic flaccid tympanic membrane on pneumatic
otoscopyotoscopy

type Ad tympanogramtype Ad tympanogram

10. Differential diagnosisDifferential diagnosis

Congenital stapes fixationCongenital stapes fixation

Family history less likely (10%)Family history less likely (10%)

usually detected in the first decade of lifeusually detected in the first decade of life

25% incidence of other congenital anomalies 25% incidence of other congenital anomalies
(3% for juvenile otosclerosis)(3% for juvenile otosclerosis)

non-progressive CHLnon-progressive CHL

11. Differential diagnosisDifferential diagnosis

Malleus head fixationMalleus head fixation

when congenital, associated with other when congenital, associated with other
stigmata (aural atresia)stigmata (aural atresia)

presence of tympanosclerosispresence of tympanosclerosis

pneumatic otoscopypneumatic otoscopy

almost always associated with type As almost always associated with type As
tympanogram (only in advanced otosclerosis)tympanogram (only in advanced otosclerosis)

12. Differential diagnosisDifferential diagnosis

PagetPaget’’s diseases disease

- diffuse involvement of the bony skeleton- diffuse involvement of the bony skeleton

- elevated alkaline phosphatase- elevated alkaline phosphatase

- CT - diffuse, bilateral, petrous bone involvement - CT - diffuse, bilateral, petrous bone involvement
with extensive with extensive

-de-mineralization-de-mineralization

- More commonly crowds the ossicles in the - More commonly crowds the ossicles in the
epitympanum, partially fixing epitympanum, partially fixing

the ossicular chainthe ossicular chain

13. Differential diagnosisDifferential diagnosis

Osteogenesis imperfectaOsteogenesis imperfecta

presence of blue sclerapresence of blue sclera

h/o of multiple bone fracturesh/o of multiple bone fractures

CT CT –– more common involves the otic capsule more common involves the otic capsule
and to a greater extentand to a greater extent

14. Surgical interventionsSurgical interventions

The best surgical candidate The best surgical candidate

good health with a socially unacceptable good health with a socially unacceptable
ABG, ABG,

a negative Rinne test, a negative Rinne test,

excellent discrimination, excellent discrimination,

the desire for surgery after an appropriate the desire for surgery after an appropriate
period of time for deliberation.period of time for deliberation.

Younger patients are more likely to develop Younger patients are more likely to develop
re-ossification of the stapes footplate over re-ossification of the stapes footplate over
their lifetime. their lifetime.

15. Surgical interventionsSurgical interventions

Most authors discourage performing Most authors discourage performing
stapes surgery in patients with Meniere's stapes surgery in patients with Meniere's
disease, especially when it is active. disease, especially when it is active.

16. Surgical interventionsSurgical interventions

StapedotomyStapedotomy

Less trauma to the oval Less trauma to the oval
windowwindow

Less possibility of Less possibility of
damaging to the inner eardamaging to the inner ear

In addition, revision In addition, revision
surgery, if required, is surgery, if required, is
easier due to preserved easier due to preserved
anatomyanatomy

stapedectomystapedectomy

18. Non-surgical interventionsNon-surgical interventions

Amplification:Amplification: hearing aide hearing aide

Patients who do not want to undergo surgery Patients who do not want to undergo surgery
for otosclerosisfor otosclerosis

patients who are not fit for surgery. patients who are not fit for surgery.

19. Non-surgical interventionsNon-surgical interventions

Medical treatment:Medical treatment:

Usual dose is about 20-120mg of fluoride a dayUsual dose is about 20-120mg of fluoride a day

Efficacy of the treatment can be evaluated 2 years Efficacy of the treatment can be evaluated 2 years
later. later.

SchwartzeSchwartze’’s sign, and the degree of tinnitus and imbalance s sign, and the degree of tinnitus and imbalance
are reassessed, and a CT scan is repeated. are reassessed, and a CT scan is repeated.

Once the disease was stable, the patient is placed on Once the disease was stable, the patient is placed on
a life-ling maintenance dose of about 25mg of fluoride a life-ling maintenance dose of about 25mg of fluoride
a day. a day.

50% of patients have stabilization of their disease, 50% of patients have stabilization of their disease,
30% improve, and the rest continue to progress. 30% improve, and the rest continue to progress.

20. Non-surgical interventionsNon-surgical interventions

Indications for medical treatment Indications for medical treatment

Not surgical candidates, Not surgical candidates,

Decide against surgery, Decide against surgery,

Patient with SNHL or vestibular symptoms Patient with SNHL or vestibular symptoms

positive Schwartzepositive Schwartze’’s sign may be given fluoride s sign may be given fluoride
treatments for 6-12 months prior to surgery to induce treatments for 6-12 months prior to surgery to induce
the focus to mature and potentially prevent the the focus to mature and potentially prevent the
progression of disease after surgery.progression of disease after surgery.

determined to be active during surgery, postoperative determined to be active during surgery, postoperative
treatment can be initiated. treatment can be initiated.