otosclerosis

1. OtosclerosisOtosclerosis
Muneeb kosvi
131/2012
MAMC

2. BackgroundBackground
 DefinitionDefinition
 Hereditary localized disease ofHereditary localized disease of
bony labyrinth resultung inbony labyrinth resultung in
 fixation of the ossicles (stapes) andfixation of the ossicles (stapes) and
conductive hearing loss.conductive hearing loss.
 Bilateral (70-85%)Bilateral (70-85%)
May have sensorineural componentMay have sensorineural component
if cochlea is involved.if cochlea is involved.

3. Bony labyrinthBony labyrinth
Periostel layer : covers the bony labyrinth
Endostel layer : innermost
Enchondral layer : develops fro cartilage and later ossifies into bone.
But some islands remain unossified and later replaces the normal dense
enchondral layer by irregularly laid spongy bone.

4. EtiologyEtiology
 Exact cause is unknown however many theories haveExact cause is unknown however many theories have
been proposed such asbeen proposed such as
 Anatomical, bony labyrinth is made ofAnatomical, bony labyrinth is made of
enchondral layer which is subjected to veryenchondral layer which is subjected to very
little change in life but some areas of cartilagelittle change in life but some areas of cartilage
are activated to form new spongy bone andare activated to form new spongy bone and
one such area isone such area is fissula ante fenestram, lyingfissula ante fenestram, lying
in front of the oval windowin front of the oval window

6.  Heredity: 50% cases with autosomalHeredity: 50% cases with autosomal
dominant traitdominant trait
 Race: whites are affected more than blackRace: whites are affected more than black
 Gender: F:M=2:1, but in India M>F andGender: F:M=2:1, but in India M>F and
Increase progression during pregnancyIncrease progression during pregnancy
 Age: 20-30 years, rare before 10 and afterAge: 20-30 years, rare before 10 and after
40 years40 years

7. Types of otosclerosisTypes of otosclerosis
 Stapedial type:Stapedial type:
 Involves oval windowInvolves oval window
 Most common typeMost common type
 Conductive deafness occurConductive deafness occur
 Cohlear type:Cohlear type:
 Involves round window and other parts of otic capsuleInvolves round window and other parts of otic capsule
 May cause sensorineural loss due to liberation of toxic material in inner earMay cause sensorineural loss due to liberation of toxic material in inner ear
 Histological type:Histological type:
 Remain asymptomaticRemain asymptomatic
 Neither conductie nor sensorineural lossNeither conductie nor sensorineural loss

8. based on area around oval window it is further divided into:based on area around oval window it is further divided into:
1.anterior focus: in front of oval window1.anterior focus: in front of oval window
2.posterior focus: behind oval window2.posterior focus: behind oval window
3.circumferential: around the margin of stapes footplate3.circumferential: around the margin of stapes footplate
4.biscuit type: in footplate but annular ligament not involved4.biscuit type: in footplate but annular ligament not involved
5.obliterative: completely obliterate oval window5.obliterative: completely obliterate oval window

9. PathologyPathology
 Two phases of diseaseTwo phases of disease
 Active (otospongiosis phase)Active (otospongiosis phase)
 Osteocytes, histiocytes, osteoblastsOsteocytes, histiocytes, osteoblasts
 Active resorption of boneActive resorption of bone
 Dilation of vesselsDilation of vessels
 Lot of cement substance which stains Blue with H&E stainLot of cement substance which stains Blue with H&E stain
called as BLUE MANTLEScalled as BLUE MANTLES
 Mature (sclerotic phase)Mature (sclerotic phase)
 Deposition of new bone (sclerotic and less dense than normalDeposition of new bone (sclerotic and less dense than normal
bone)bone)

10. PathophysiologyPathophysiology
 Conductive hearing loss-Conductive hearing loss- oval windowoval window
sclerosis.sclerosis.
 SNHLSNHL- Hyalinization of- Hyalinization of spiral ligamentspiral ligament ,,
toxins.toxins.
 Vestibular symptoms-Vestibular symptoms- degeneration ofdegeneration of
scarpa’s ganglionscarpa’s ganglion . Soluble toxic. Soluble toxic
substancessubstances

11. SymptomsSymptoms
 Hearing lossHearing loss: Slowly progressive, painless, bilateral: Slowly progressive, painless, bilateral
(80%), asymmetric, conductive hearing loss.(80%), asymmetric, conductive hearing loss.
 TinnitusTinnitus: 75% patients and seen commonly in cochlear: 75% patients and seen commonly in cochlear
and active lesion and is roaring, hissing typeand active lesion and is roaring, hissing type
 Paracusis Willissi: patient hear better in noisy
surroundings.
 Vestibular symptoms: uncommon
 Speech: quiet voice and low volume

12. Paracussis willissiParacussis willissi
 when the condutive loss reaches level of 25-
30db patient find it difficult to understand
speech. But in noisy enviorment people with
normal hearing raise their voices above the
noise level, so that they can remove the masking
effects of the noise, and this level of speech
sound is above the threshold of the patient with
conductive deafness.

13. DiagnosisDiagnosis
 History:History:
 Women in her 20s or 30sWomen in her 20s or 30s
 Conductive or Mixed hearing lossConductive or Mixed hearing loss
 Slowly progressive,Slowly progressive,
 Bilateral (80%)Bilateral (80%)
 asymmetricasymmetric
 Tinnitus (75%)Tinnitus (75%)
 Vestibular symptoms (25%)Vestibular symptoms (25%)
 2/32/3rdrd
patients have a positive family hisrorypatients have a positive family hisrory

14.  ExaminationExamination
 OtomicroscopyOtomicroscopy
 Tm appears normal and mobileTm appears normal and mobile
 Schwartze sign: seen only in 10%Schwartze sign: seen only in 10%
Reddish hue ay be seen on the promontery through the TmReddish hue ay be seen on the promontery through the Tm
which is indicative of active focus and increased vascularitywhich is indicative of active focus and increased vascularity
 Tuning fork testsTuning fork tests
 Rinne:Rinne:
 Hearing loss progresses form low frequencies to highHearing loss progresses form low frequencies to high
frequenciesfrequencies
 256, 512, and 1024 Hz TF should be used256, 512, and 1024 Hz TF should be used
 256 Hz – negative test indicates at least a 20 dB ABG256 Hz – negative test indicates at least a 20 dB ABG
 512 Hz – negative test indicates at least a 25 dB ABG512 Hz – negative test indicates at least a 25 dB ABG
 Weber test: laterization to ear with greater hearing lossWeber test: laterization to ear with greater hearing loss
 Absolute bone conduction: may be normal but decreased inAbsolute bone conduction: may be normal but decreased in
cochlear otosclerosiscochlear otosclerosis

15. AudiometryAudiometry
 TympanometryTympanometry
 Impedance testingImpedance testing
 Acoustic reflexesAcoustic reflexes
 Pure tonesPure tones

16. AudiometryAudiometry
 Impedene audiometryImpedene audiometry
 Early disease shows Type A tympanogramEarly disease shows Type A tympanogram
 Progressive stapes fixation result in As curveProgressive stapes fixation result in As curve
 Acoustic reflexAcoustic reflex
 In normal person: Sustained decrease inIn normal person: Sustained decrease in
compliacne till the stimulus last.compliacne till the stimulus last.
 In otosclerosis (early stage): biphasic on-offIn otosclerosis (early stage): biphasic on-off
pattern seen in which brief increase inpattern seen in which brief increase in
compliance at onset and termination ofcompliance at onset and termination of
stimulusstimulus
 In otosclerosis (late): reflex is absentIn otosclerosis (late): reflex is absent

17.  Pure tone audiometryPure tone audiometry
 Most useful audiometric test for otosclerosisMost useful audiometric test for otosclerosis
 Characterizes the severity of diseaseCharacterizes the severity of disease
 Frequency specificFrequency specific
 Low frequencies affected first(Below 1000 Hz)Low frequencies affected first(Below 1000 Hz)
 Air line flattens with disease progressionAir line flattens with disease progression
 Carhart’s notchCarhart’s notch
 Hallmark audiologic sign of otosclerosisHallmark audiologic sign of otosclerosis
 Decrease in bone conduction thresholdsDecrease in bone conduction thresholds
 5 dB at 500 Hz5 dB at 500 Hz
 10 dB at 1000 Hz10 dB at 1000 Hz
 15 dB at 2000 Hz (maximum)15 dB at 2000 Hz (maximum)
 5 dB at 4000 Hz5 dB at 4000 Hz

19.  One element in bone conduction is inertia whichOne element in bone conduction is inertia which
is due to weight of ossicular chain & stapesis due to weight of ossicular chain & stapes
vibrate out of phase with the skull as a wholevibrate out of phase with the skull as a whole
when we place vibrating tuning fork but due towhen we place vibrating tuning fork but due to
stapes fixation it is no longer free to vibrate sostapes fixation it is no longer free to vibrate so
inertial component of bone conduction is lostinertial component of bone conduction is lost
and bone conduction decreases.and bone conduction decreases.
 Effect may disappear after stapedectomy andEffect may disappear after stapedectomy and
this phenomenon is called over –closure of A-Bthis phenomenon is called over –closure of A-B
gap. It means after surgery only conductiongap. It means after surgery only conduction
threshold are measuredthreshold are measured

20. Classical audiometric findingsClassical audiometric findings
 C = conductive hearing loss for lowC = conductive hearing loss for low
frequenciesfrequencies
= cahart’s notch= cahart’s notch
 A = acoustic reflex (diphasic/absent)A = acoustic reflex (diphasic/absent)
 R = rinne test negativeR = rinne test negative
 T = Typanogram (A/As)T = Typanogram (A/As)

21.  Computed tomography (CT) of theComputed tomography (CT) of the
temporal bonetemporal bone
 Pre-opPre-op
 Characterize the extent of otosclerosisCharacterize the extent of otosclerosis
 Evaluate for enlarge cochlear aqueductEvaluate for enlarge cochlear aqueduct
 It reveal normal round window and normal mastoidIt reveal normal round window and normal mastoid
pneumatization.pneumatization.
 Post-opPost-op
 prosthesis dislocationprosthesis dislocation

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

23. 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 anomalies25% incidence of other congenital anomalies
(3% for juvenile otosclerosis)(3% for juvenile otosclerosis)
 non-progressive CHLnon-progressive CHL

24. Differential diagnosisDifferential diagnosis
 Malleus head fixationMalleus head fixation
 whenwhen congenitalcongenital, associated with other, associated with other
stigmata (aural atresia)stigmata (aural atresia)
 presence ofpresence of tympanosclerosistympanosclerosis
 pneumatic otoscopypneumatic otoscopy
 almost always associated with type Asalmost always associated with type As
tympanogram (only in advanced otosclerosis)tympanogram (only in advanced otosclerosis)

25. 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 de-mineralizationwith extensive de-mineralization

26. Differential diagnosisDifferential diagnosis
 Osteogenesis imperfectOsteogenesis imperfect
 Vaen de hoeve syndromeVaen de hoeve syndrome
 presence of blue sclerapresence of blue sclera
 multiple bone fracturesmultiple bone fractures
 CTCT –– more common involves the otic capsulemore common involves the otic capsule
and to a greater extentand to a greater extent
 Histologically can’t distinguish fromHistologically can’t distinguish from
otosclerosisotosclerosis

27. TreatmentTreatment

28. MedicalMedical
 No medical treatment that can cure this dsNo medical treatment that can cure this ds
 Controversies exist for the available options andControversies exist for the available options and
generally not recommendedgenerally not recommended
 Sodium FluorideSodium Fluoride
 Reduces osteoclastic resorption and increases osteoblasticReduces osteoclastic resorption and increases osteoblastic
bone formationbone formation
 Dose – 50-70mg for 1-2 yearsDose – 50-70mg for 1-2 years
 IndicationsIndications
 Non-surgical candidatesNon-surgical candidates
 Surgical candidates with + Schwartze’s signSurgical candidates with + Schwartze’s sign
 Cochlear otosclerosisCochlear otosclerosis
 Disadvantage: fracture long bone and spineDisadvantage: fracture long bone and spine
 Contraindication: children, pregnant, chronic arthritis/nephritisContraindication: children, pregnant, chronic arthritis/nephritis

29.  BisphosphonatesBisphosphonates
 Inhibits bone resorption by inhibitingInhibits bone resorption by inhibiting
osteoclastic activity.osteoclastic activity.
 No effect on bone formationNo effect on bone formation
 Side effect: GI symptomsSide effect: GI symptoms
 Hearing aidHearing aid
 For people with normal cochlear function andFor people with normal cochlear function and
good speech discriminationgood speech discrimination

30. SurgicalSurgical
 Treatment of choice and 90% patientTreatment of choice and 90% patient
show good improvementshow good improvement
 StepedectomyStepedectomy: removing the stapes bone: removing the stapes bone
and replacing it with a micro prosthesisand replacing it with a micro prosthesis
 StapedotomyStapedotomy: creating a small hole in the: creating a small hole in the
fixed stapes footplate and inserting a tiny,fixed stapes footplate and inserting a tiny,
piston-like prosthesispiston-like prosthesis

31.  Best surgical candidateBest surgical candidate
 Air conduction level 30dB or worseAir conduction level 30dB or worse
 Bone conduction level 0 – 25 dBBone conduction level 0 – 25 dB
 Air-Bone Gap 15 dBAir-Bone Gap 15 dB
 Discrimination score >60%Discrimination score >60%
 Rhinne –ve for 256 and 512hzRhinne –ve for 256 and 512hz

32. Steps of surgerySteps of surgery
Canal InjectionCanal Injection
 2-3 cc of 1% lidocaine2-3 cc of 1% lidocaine
with 1:50,000 orwith 1:50,000 or
1:100,000 epinephrine1:100,000 epinephrine
 4 quadrants4 quadrants
 Bony cartilaginousBony cartilaginous
junctionjunction

33. Raise Tympanomeatal FlapRaise Tympanomeatal Flap
 6 and 12 o’clock6 and 12 o’clock
positionspositions
 6-8 mm lateral to the6-8 mm lateral to the
annulusannulus

34. Separation of chorda tympani nerveSeparation of chorda tympani nerve
from malleusfrom malleus
 Separate the chordaSeparate the chorda
from the medialfrom the medial
surface of the malleussurface of the malleus
to gain slackto gain slack
 Avoid stretching the n.Avoid stretching the n.

35. Curettage of ScutumCurettage of Scutum
 Curettage a troughCurettage a trough
lateral to the scutum,lateral to the scutum,
thinning itthinning it
 Then remove theThen remove the
scutum (incus to thescutum (incus to the
round window)round window)
 Visualize the pyramidalVisualize the pyramidal
process and facial n.process and facial n.

37. Total StapedectomyTotal Stapedectomy
 UsesUses
 Extensive fixation of the footplateExtensive fixation of the footplate
 Floating footplateFloating footplate
 DisadvantagesDisadvantages
 Increased post-op vestibular symptomsIncreased post-op vestibular symptoms
 More technically difficultMore technically difficult
 Increased potential for prosthesis migrationIncreased potential for prosthesis migration

40. Stapedotomy/Small FenestraStapedotomy/Small Fenestra
 Originally for obliterated or solid footplatesOriginally for obliterated or solid footplates
AdvantagesAdvantages
Less trauma to the vestibuleLess trauma to the vestibule
Less incidence of prosthesis migrationLess incidence of prosthesis migration
Less fixation of prosthesis by scar tissueLess fixation of prosthesis by scar tissue

41. Drill FenestrationDrill Fenestration
 0.7mm diamond burr0.7mm diamond burr
 Motion of the burrMotion of the burr
removes bone dustremoves bone dust
 Avoids smokeAvoids smoke
productionproduction
 Avoids surrounding heatAvoids surrounding heat
productionproduction

42. Laser FenestrationLaser Fenestration
 LaserLaser
 Avoids manipulation of the footplateAvoids manipulation of the footplate
 Argon and Potassium titanyl phosphate (KTP/532)Argon and Potassium titanyl phosphate (KTP/532)
 Wave length 500 nmWave length 500 nm
 Visible lightVisible light
 Absorbed by hemoglobinAbsorbed by hemoglobin
 Surgical and aiming beamSurgical and aiming beam
 Carbon dioxide (CO2)Carbon dioxide (CO2)
 10,000 nm10,000 nm
 Not in visible light rangeNot in visible light range
 Surgical beam onlySurgical beam only
 Requires separate laser for an aiming beam (red helium-neon)Requires separate laser for an aiming beam (red helium-neon)
 Ill defined fuzzy beamIll defined fuzzy beam

48. ContraindicationContraindication
 A - active/malignant otosclerosisA - active/malignant otosclerosis
 I - inner ear malformationI - inner ear malformation
 P - pregnancyP - pregnancy
 M - medically unfitM - medically unfit
 T - tympanic membrane perforationT - tympanic membrane perforation
 O - only hearing earO - only hearing ear
 O - otitis external/mediaO - otitis external/media
 O – occupation like athlete, divers,O – occupation like athlete, divers,
frequent air traveler, working in noisyfrequent air traveler, working in noisy
surroundingssurroundings

49. ComplicationsComplications
 Tear of tymanomeatal flap and Tm perforationTear of tymanomeatal flap and Tm perforation
 Injury to chorda tympani and taste disturbancesInjury to chorda tympani and taste disturbances
 Incus dislocationIncus dislocation
 VertigoVertigo
 Perilymph fistula/granulomaPerilymph fistula/granuloma
 Conductive loss due to short/long/displacedConductive loss due to short/long/displaced
prosthesisprosthesis
 Sensorineural loss due to intraopSensorineural loss due to intraop
trauma/labyrinthitistrauma/labyrinthitis
 Dead earDead ear

50. Thank you