otosclerosis

OtosclerosiOtosclerosis s

Mr. Ashok bishnoiMr. Ashok bishnoi

Lecturer JINRLecturer JINR

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

Incidence:-Incidence:-

Age Age The incidence of otosclerosis increases The incidence of otosclerosis increases

with age. with age. The most common age group presenting The most common age group presenting

with hearing loss from otosclerosis is 15-with hearing loss from otosclerosis is 15-45 years, 45 years,

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, ,

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

Clinical manifestation:-Clinical manifestation:-

Hearing lossHearing loss Schwartz’s sign Schwartz’s sign (Normal appearing tympanic (Normal appearing tympanic

membrane (a pink colour is noted through the tympanic membrane (a pink colour is noted through the tympanic membrane)membrane)

Absent acoustic reflexAbsent acoustic reflex TinitusTinitus Quiet well modulated voiceQuiet well modulated voice

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:

AudiometryAudiometryOtoscopic examinationOtoscopic examination

Image study Image study

CT can characterize the extent CT can characterize the extent of the otosclerotic focus at the of the otosclerotic focus at the oval window oval window

CT scan can exclude capsular CT scan can exclude capsular involvement when patients involvement when patients have significant mixed hearing have significant mixed hearing loss loss

An enlarged cochlear aqueduct An enlarged cochlear aqueduct may be seen which potential may be seen which potential causes perilymph gusher causes perilymph gusher during footplate fenestration or during footplate fenestration or removal. removal.

It reveal normal round window It reveal normal round window and normal mastoid and normal mastoid pneumatization.pneumatization.

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 flaccid tympanic membrane on

pneumatic otoscopypneumatic otoscopy type Ad tympanogramtype Ad tympanogram


Congenital stapes fixationCongenital stapes fixation Family history less likely (10%)Family history less likely (10%) usually detected in the first decade of usually detected in the first decade of

lifelife 25% incidence of other congenital 25% incidence of other congenital

anomalies (3% for juvenile otosclerosis)anomalies (3% for juvenile otosclerosis) non-progressive CHLnon-progressive CHL


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 tympanogram (only in advanced otosclerosis)otosclerosis)


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 - CT - diffuse, bilateral, petrous bone

involvement with extensive involvement 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


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 more common involves the otic

capsule and to a greater extentcapsule and to a greater extent

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.


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


StapedotomyStapedotomy Less trauma to the oval Less trauma to the oval

windowwindow Less possibility of Less possibility of

damaging to the inner damaging to the inner earear

In addition, revision In addition, revision surgery, if required, is surgery, if required, is easier due to preserved easier due to preserved anatomyanatomy

stapedectomystapedectomy

Non-surgical Non-surgical interventionsinterventions

Amplification:Amplification: hearing aide hearing aide Patients who do not want to undergo Patients who do not want to undergo

surgery for otosclerosissurgery for otosclerosis patients who are not fit for surgery. patients who are not fit for surgery.


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 Efficacy of the treatment can be evaluated 2

years later. years later. SchwartzeSchwartze’’s sign, and the degree of tinnitus and s sign, and the degree of tinnitus and

imbalance are reassessed, and a CT scan is repeated. imbalance are reassessed, and a CT scan is repeated. Once the disease was stable, the patient is Once the disease was stable, the patient is

placed on a life-ling maintenance dose of about placed on a life-ling maintenance dose of about 25mg of fluoride a day. 25mg of fluoride a day.

50% of patients have stabilization of their 50% of patients have stabilization of their disease, 30% improve, and the rest continue to disease, 30% improve, and the rest continue to progress. progress.


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 treatments for 6-12 months prior to surgery to induce the focus to mature and potentially induce the focus to mature and potentially prevent the progression of disease after prevent the progression of disease after surgery.surgery.

determined to be active during surgery, determined to be active during surgery, postoperative treatment can be initiated. postoperative treatment can be initiated.

otosclerosis

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