耳硬化症的诊断和治疗.ppt

Otosclerosis,ChunfuDaiOtolaryngologyDepartmentFudanUniversity,Background,DefinitionprimarymetabolicbonediseaseoftheoticcapsuleandossiclesItcausesfixationoftheossicles(stapes)Itresultsinconductiveormixedhearingloss.Itisgenetically-mediatedviaautosomaldominanttransmission,Epidemiology,RaceincidenceofmicroscopicotosclerosisCaucasian10%Asian5%AfricanAmerican1%NativeAmerican0%,Epidemiology,Sexvariation(M:F=1:2.5)Womenmorecommonlyseekmedicalattentionforhearinglosssecondarytootosclerosis,histologicstudiesprevalenceofotosclerosisshownodifferenceinmenversuswomen.,Epidemiology,AgeTheincidenceofotosclerosisincreaseswithage.Themostcommonagegrouppresentingwithhearinglossfromotosclerosisis15-45years,howeverithasbeenreportedtomanifestasearlyas7yearsandaslateasthemid50s.,Etiology,Manytheorieshavebeenproposedsuchashereditary,54%ofpatientspresentwithfamilyhistoryendocrine,womenwithpregnancyworseherhearingmetabolic,enzymeabnormalwaspathogeninfectious,viruswasidentifiedinthelesionvascular,autoimmune,nonehavebeproven.Hormonalfactorshavebeensuggestedtoplayaroleinotosclerosisbasedontheobservationthatpregnancysometimesacceleratestheprogressionofthedisease.,Pathophysiology,Otosclerosis(otospongiosis)isanosseousdyscrasia,limitedtothetemporalbone,andcharacterizedbyresorptionandformationofnewboneintheareaoftheossiclesandoticcapsule.,Pathophysiology,Themostcommonsiteofinvolvementistheanteriorovalwindownearthefistulaantefenestrum.Whenboththeanteriorandposteriorendsofthefootplateareinvolveditistermed“bipolar”involvementorfixation(ifthefootplateisimmobile).Ifonlythefootplateisinvolved,itissometimesreferredtoasa“stapedialotosclerosis”.Whentheentirefootplateandannularligamentareinvolveditisknownasanobliteratedfootplateorobliterativeotosclerosis.Theroundwindowisinvolvedinapproximately30%to50%ofcases,Pathophysiology,otosclerosishastwomainforms:anearlyofspongioticphase(otospongiosis)Theearlyphaseischaracterizedbymultipleactivecellgroupsincludingosteocytes,osteoblasts,andhistiocytes.Itdevelopsaspongyappearancebecauseofvasculardilationsecondarytoosteocyteresorptionofbonesurroundingbloodvessels.Thiscanbeseengrosslyasredhuebehindthetympanicmembranetermed“Schwartzessign”,Pathophysiology,otosclerosishastwomainformsalateorscleroticphasedensescleroticboneformsintheareasofpreviousresorption.Boththescleroticandspongioticaswellasintermediatephasesmaybepresentatthesametime.Otoscleroticfocialwaysbegininendochondralbonebutmayprogresstoinvolveendostealandperiosteallayersandevenenterintothemembranouslabyrinth.,Pathophysiology,Microscopically,afocusofactiveotosclerosisrevealsfingerprojectionsofdisorganizedbone,richinosteocytesparticularlyattheleadingedge.Inthecenterofthefocus,multinucleatedosteocytesareoftenpresent.Inthescleroticphase,Diagnosis,Slowlyprogressive,bilateral(80%),asymmetric,conductivehearinglossTinnitusisassociatedwith75%patientsTheageofonsetofhearinglossisyoungHistoryofsignificantearinfectionsmakesthediagnosisofotosclerosislesslikely.25%ofpatientspresentwithsomevestibularcomplaints,Diagnosis,low-volumespeech.conductivenatureoftheirhearingloss,theyperceivetherevoiceaslouderthanitactuallyis.ParacusisofWillis.ItoccursbecausetheCHLreducesthevolumeofthebackgroundnoise,Two-thirdsofpatientswillreportafamilyhistoryofhearingloss.Womenwithpregnancyworseherhearing,Physicalexamination,TMappearsnormalinthemajorityofpatientsSchwartzesignisobservedin10%ofpatients).Rinnetest:negativeEarlyinthedisease,lowfrequencyCHLwillpredominateresultinginanegativeRinnetestwiththe256-Hzonly.Asprogressionoccurs,the512andthenthe1,024-HzTFwillbecomenegative.Webertest:laterizationtopoorHLSchwabachtest:prolongedboneconductionGelletest:negative,typeAs(s-stiffnesscurve)tympanogramandischaracteristicofadvancedotosclerosisbutmorecommonly,malleusfixation.,Tests,PuretoneaudiometryEarlystage:adecreaseinairconductioninthelowfrequency,especiallybelow1000Hz.Asthediseaseprogresses,theairlineflattens.becausetheotoscleroticfocushasamassaffectontheentiresystem,carhartnotchisnoted.Furtherprogressionofotosclerosistoinvolvethecochleamayresultinincreasedboneconductionthresholdsinhighfrequency,A-Bgapexistsinlowfrequency.Moreisolatedcochlearotosclerosismaysometimesresultinamixedhearinglosswitha“cookie-bite”patternwithbothairandbonelines.,Tests,CarhartnotchCarhartnotchisthehallmarkaudiologicsignofotosclerosis.Itischaracterizedbyadecreasedintheboneconductionthresholdsofapproximately5dBat500Hz,10dBat1000Hz,15dBat2000Hz,and5dBat4000Hz.,Imagestudy,CTcancharacterizetheextentoftheotoscleroticfocusattheovalwindowCTscancanexcludecapsularinvolvementwhenpatientshavesignificantmixedhearinglossAnenlargedcochlearaqueductmaybeseenwhichpotentialcausesperilymphgusherduringfootplatefenestrationorremoval.Itrevealnormalroundwindowandnormalmastoidpneumatization.,Differentialdiagnosis,Ossiculardiscontinuityconductivelossof60dbusuallywithoutsensorineuralcomponentflaccidtympanicmembraneonpneumaticotoscopytypeAdtympanogram,Differentialdiagnosis,CongenitalstapesfixationFamilyhistorylesslikely(10%)usuallydetectedinthefirstdecadeoflife25%incidenceofothercongenitalanomalies(3%forjuvenileotosclerosis)non-progressiveCHL,Differentialdiagnosis,Malleusheadfixationwhencongenital,associatedwithotherstigmata(auralatresia)presenceoftympanosclerosispneumaticotoscopyalmostalwaysassociatedwithtypeAstympanogram(onlyinadvancedotosclerosis),Differentialdiagnosis,Pagetsdisease-diffuseinvolvementofthebonyskeleton-elevatedalkalinephosphatase-CT-diffuse,bilateral,petrousboneinvolvementwithextensive-de-mineralization-Morecommonlycrowdstheossiclesintheepitympanum,partiallyfixingtheossicularchain,Differentialdiagnosis,Osteogenesisimperfectapresenceofbluesclerah/oofmultiplebonefracturesCTmorecommoninvolvestheoticcapsuleandtoagreaterextent,Surgicalinterventions,ThebestsurgicalcandidategoodhealthwithasociallyunacceptableABG,anegativeRinnetest,excellentdiscrimination,thedesireforsurgeryafteranappropriateperiodoftimefordeliberation.Youngerpatientsaremorelikelytodevelopre-ossificationofthestapesfootplateovertheirlifetime.,Surgicalinterventions,MostauthorsdiscourageperformingstapessurgeryinpatientswithMenieresdisease,especiallywhenitisactive.,Surgicalinterventions,StapedotomyLesstraumatotheovalwindowLesspossibilityofdamagingtotheinnerearInaddition,revisionsurgery,ifrequired,iseasierduetopreservedanatomystapedectomy,Non-surgicalinterventions,Amplification:hearingaidePatientswhodonotwanttoundergosurgeryforotosclerosispatientswhoarenotfitforsurgery.,Non-surgicalinterventions,Medicaltreatment:Usualdoseisabout20-