Braz. j. . vol.81 número5

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www.bjorl.org

Brazilian

Journal

of

OTORHINOLARYNGOLOGY

ORIGINAL

ARTICLE

Variables

with

prognostic

value

in

the

onset

of

idiopathic

sudden

sensorineural

hearing

loss

夽

,

夽夽

Eduardo

Amaro

Bogaz,

André

Souza

de

Albuquerque

Maranhão

∗

_,

Daniel

Paganini

Inoue,

Flavia

Alencar

de

Barros

Suzuki,

Norma

de

Oliveira

Penido

DepartmentofOtolaryngologyandHeadandNeckSurgery,UniversidadeFederaldeSãoPaulo(UNIFESP),SãoPaulo,SP,Brazil

Received19April2014;accepted14September2014 Availableonline22July2015

KEYWORDS

Prognosis;

Suddenhearingloss; Audiometry

Abstract

Introduction:Theestablishmentofanindividualizedprognosticevaluationinpatientswitha diagnosisofidiopathicsuddensensorineuralhearingloss(ISSHL)remainsadifficultand impre-cisetask,duemostlytothevarietyofetiologies.Determiningwhichvariableshaveprognostic valueintheinitialassessmentofthepatientwouldbeextremelyusefulinclinicalpractice.

Objective:To establish which variables identifiable at the onset ofidiopathic sudden sen-sorineuralhearinglosshaveprognosticvalueinthefinalhearingrecovery.

Methods:Prospective,longitudinalcohortstudy.PatientswithISSHLfollowedbythe Depart-mentofOtology-Neurotologyofaquaternaryhospitalwereincluded.Thefollowingvariables wereevaluatedandcorrelatedwithfinalhearingrecovery:age,gender,vertigo,tinnitus,initial degreeofhearingloss,contralateralearhearing,andelapsedtimetotreatment.

Results:127patientswithISSHLwereevaluated.Ratesofabsoluteandrelativerecoverywere 23.6dBand37.2%respectively.Completehearingimprovementwasobservedin15.7%patients; 27.6%demonstratedsignificantimprovementandimprovementwasnotedin57.5%.

Conclusion:DuringtheonsetofISSHL,thefollowingvariableswerecorrelatedwithaworse prognosis:dizziness,profoundhearingloss,impairedhearinginthecontralateralear,anddelay tostarttreatment.TinnitusattheonsetofISSHLcorrelatedwithabetterprognosis.

夽

Pleasecitethisarticleas:BogazEA,MaranhaoASA,InoueDP,SuzukiFAB,PenidoNO.Variableswithprognosticvalueintheonsetof idiopathicsuddensensorineuralhearingloss.2015;81:520---6.

夽夽_Institution:_Department_of_{Otolaryngology}_and_Head_and_Neck_Surgery,_Escola_Paulista_de_Medicina,_Universidade_Federal_de_São_Paulo

(UNIFESP-EPM),SãoPaulo,SP,Brazil.

∗_{Corresponding}_author.

E-mail:andremaranhao@hotmail.com(A.S.d.A.Maranhão). http://dx.doi.org/10.1016/j.bjorl.2015.07.012

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PALAVRAS-CHAVE

Prognóstico;

Perdaauditivasúbita; Audiometria

Variáveiscomvalorprognósticonomomentodainstalac¸ãodaperdaauditiva neurossensorialsúbitaidiopática

Resumo

Introdução: Elaboraravaliaçãoprognósticaindividualizadaem pacientescomdiagnósticode perdaauditivaneurossensorialsúbitaidiopática (PANSI)permanecetarefaárduaeimprecisa devido,emgrandeparte,àvariedadedeetiologias.Adeterminaçãodequaisvariáveisteriam valorprognósticonaavaliaçãoinicialdopacienteseriadeextremautilidadenapráticaclínica.

Objetivo: Estabelecer quais variáveis, identificáveis no momento de instalac¸ão da perda auditiva neurossensorial súbita idiopática, têm valor prognóstico na recuperac¸ão auditiva final.

Método: Estudo de coorte prospectivo, longitudinal. Incluídos pacientes com PANSI acom-panhados pelaDisciplinadeOtologia---Neurotologiadeumhospitalquaternário. Asseguintes variáveisforamavaliadasecorrelacionadascomarecuperac¸ãoauditivafinal:idade,gênero, vertigem,zumbido,graudeperdaauditivainicial,audic¸ãonaorelhacontralateral,tempopara iníciodetratamento.

Resultado: Foramavaliados127pacientescomPANSI.Astaxasderecuperac¸ãoabsolutae rela-tivaforam23,6dBe37,2%respectivamente.Apresentarammelhoracompletadaaudic¸ão15,7% dospacientes;27,6%apresentarammelhorasignificativae57,5%melhora.

Conclusão:NomomentodainstalaçãodaPANSI,asseguintesvariáveiscorrelacionaram-secom piorprognóstico:vertigem,perdaauditivaprofunda,audiçãoalteradanaorelhacontralaterale demoraparainíciodotratamento.PresençadezumbidonainstalaçãodaPANSIcorrelacionou-se commelhorprognóstico.

Introduction

Idiopathicsuddensensorineuralhearingloss(ISSHL)is char-acterizedbytheoccurrenceofahearinglossofatleast30dB inthreecontiguousfrequencies,withitsonsetinaperiod fromafewhoursuptothreedays.1_Despite_being_relatively

common,withanincidenceof5---20casesper100,000

peo-pleperyear,2_the_{physiopathogenesis}_of_ISSHL_remains_to_be

clarified.ArecurringdrawbackinISSHLisadelayinits

diag-nosisand,duetoavarietyofetiologies,an individualized

prognosticassessmentremainsdifficulttoestablish,andis

frequentlyinaccurate.

Several case seriesindicate thatISSHL typicallyoccurs

inpatientsaged43---53years,withnopredilectionfor

gen-der.Spontaneousrecoveryofhearingthresholdisobserved

inaboutone-thirdto65%ofcases.1,3_Despite_the_lack_of

con-sistentdataontreatmentofISSHL,systemiccorticosteroids

havebeenusedinclinicalpracticeasthedrugofchoice.4,5

Studieswithafocusonprognosticfactorshavereceived

limited attention and are usually neglected in lieu of

research on treatment and etiology.6 _Determining _which

variableswouldhave prognosticvalue inan initialpatient

evaluationwould beextremely useful inclinical practice,

as it would allow an individual classification of patients

accordingtotheseverityofeachcase,aswellasthe

estab-lishmentofamoreaccurateprognosisfor eachindividual,

anddefiningwhichpatientswouldbebenefitedwiththeuse

ofcorticosteroids.Inaddition,itwouldbepossibletomore

preciselyinformpatientsabouttherealchancesofhearing

recovery,inadditiontoavoid theuseof corticosteroids

---an oftenunnecessarytherapy.Finally,it wouldstrengthen

the efforts to change the current paradigm of empirical

treatmentofISSHL.

Thisstudyaimstoestablishwhichvariablesidentifiable

attheonsetofidiopathicsuddensensorineuralhearingloss

haveprognosticvalueinthefinalhearingrecovery.

Methods

This was a prospective, longitudinal cohort study that

includedpatientswithISSHLattendedtoattheSudden

Deaf-nessOutpatientClinicandfollowed-upbytheDepartmentof

Otology-Neurotologyataquaternaryhospital.Thisproject

wasapprovedbytheinstitution’sEthicsCommittee,under

protocol0715/11.

Allpatientswere treatedwithprednisone1mg/kg/day

(maximumdailydose=60mg)POfor at leastaweek. The

dosewasreducedweeklyforupto21days.Thosepatients

withcontraindications to the use of this dosage of

pred-nisone had their dose reduced; or, in some rare cases,

replacedbydeflazacort.

Patients with a history of middle and inner ear

dis-ease with a defined etiology such as trauma, infection,

perilymphaticfistula,retrocochleardisease(schwannoma),

degenerativedisease of the centralnervous system

(mul-tiple sclerosis), exposure to ototoxic drugs, barotrauma,

middle or inner ear malformation, history suggestive of

mumps,definite Ménière’s disease, bilateral ISSHL cases,

andpatientswhohadtheonsetofmonitoringnotbeginuntil

45daysaftertheonsetofhearinglosswereexcludedfrom

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Table1 ANOVAtestsamongagegroupsforrecoveryrates.

Agegroup ANOVA

≤30 31---50 51---70 ≥71 p

AbsolutePTArecovery

Mean 14.22 28.46 25.07 14.06

Standarddeviation 16.66 27.91 23.53 12.90 0.085

n 22 43 54 8

RelativePTArecovery

Mean 22.28% 45.03% 39.03% 23.98%

Standarddeviation 29.62% 43.16% 32.77% 19.80% 0.072

n 22 43 54 8

PTA,puretoneaverage.

Thehearingassessmentofpatientswasperformedwith anMAICOMA-41audiometer,andalltestswereperformed bythe samespeechtherapist. The initialand final audio-metricparameterswereevaluated;thelastevaluationwas obtainedtwomonthsaftertheinitialaudiometry,orbefore inthosepatientswithafullrecovery.Inpatientswherethe hearingthresholdsofprofoundlosseswerenotdetected,the maximumaudiometriclimitwasconsideredastheresponse (inthiscase,120dB).

In all patients, the means of initial and final pure toneswere obtained, according to the group of frequen-ciesaffected.Whenlowandmediumtoneswereinvolved, themeansof 0.25,0.5,1, and2kHzfrequencies was cal-culated;whenmediumandhighfrequencieswereaffected, themeansof1,2,3,4,6,and8kHzfrequencieswere cal-culated;whenonlyhighfrequencytoneswereinvolved,the means of3, 4, 6,and 8kHz frequencies werecalculated; andfinallywhenlow,medium, andhigh frequencieswere affected,themeanofalleightfrequencieswascalculated. Levels of 250 and 500Hz; 1 and 2kHz; and 3, 4, 6, and 8kHzwereconsideredlow,medium,andhighfrequencies, respectively.

Thefollowinghearingrecoverycriteriawereused:

• Improvement: a change of functional category, and improvementof15dB.

• Significantimprovement:therewasimprovement,witha finalhearinglossofmildintensity.

• Fullimprovement:therewasimprovement,withhearing thresholdsreturningtonormal(25dB).

Tocalculatehearingrecovery,Tuccietal.7_has_suggested

the use of audiometric thresholds for the unaffected ear

asa baseline value, under the premise that therewas a

symmetrical hearing level before the ISSHL episode. For

this calculation, the author took into account only the

initial pure tone average (PTA) from the unaffected ear.

However, in the present study used the initial and final

PTAvalues for theunaffected side, withthe objectiveof

reducing both systematic and random errors, taking into

accountthatthemeasuresontheaffectedandunaffected

sides were obtained at the same time. Therefore, PTA

relative recovery was calculated using the following

for-mula,indB:

PTArecovery(dB)=(PTAIA−PTAINA)−(PTAFA−PTAFNA).

ThecalculationofPTArelativerecovery(asapercentage)

wascarriedoutwiththeuseofthefollowingformula:

PTArecovery(%)=(PTAIA−PTAINA)−(PTAFA−PTAFNA)

×100/(PTAIA−PTAINA).

where PTAIAis theinitialPTAof theaffectedear;PTAINA

is theinitial PTAofthe unaffectedear;PTAFAisthe final

PTAoftheaffectedear;andPTAFNAisthefinalPTAofthe

unaffectedear.

The following variableswere evaluatedand correlated

withPTArecoveryrates:age,gender,vertigo,tinnitus,

ini-tialdegreeofhearingloss,hearinginthecontralateralear,

andtimetoonsetoftreatment.

Inthestatisticalanalysis,independentStudent’st-tests

wereusedwhencomparingtwogroups,andANOVA(analysis

ofvariance)testswereusedwhencomparingthreeormore

groups,consideringasignificancelevelof5%.

Results

From2000to2010,277patientswithISSHLwereevaluated

attheSuddenDeafnessOutpatientClinic.Ofthistotal,eight

patients didnotmeet thedefinitioncriteriaforloss ofat

least30dBinatleastthreeconsecutivefrequencies.In

addi-tion,tencaseswerebilateral;andin33patientsthecause

ofhearinglosswasfound.Seventy-fivepatientswerelostto

follow-up,andin24patientstheinformedconsentwasnot

obtained.Therefore,takingintoaccounttheinclusionand

exclusioncriteria,thefinalsamplecontained127patients.

The absolute and relative recovery rates were 23.6dB

and 37.2%, respectively. 15.7% of patients showed full

improvement,27.6% showedsignificant improvement,and

57.5%showedimprovement.

The average age was 48 years (range 12---82 years).

Table 1shows PTArecovery rates in differentagegroups.

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Table2 Independent Student’s t-tests between genders forrecoveryrates.

Gender t-test

Female Male Patient

Mean 24.06 23.23

Standarddeviation 25.01 23.22 0.847

n 64 63

Mean 36.74 37.70

n 64 63

Table3 IndependentStudent’st-testsbetweenpresence andabsenceoftinnitusforrecoveryrates.

Tinnitus t-test

No Yes p

Mean 5.81 25.17

n 10 117

Mean 13.44% 39.25%

Standarddeviation 41.63% 35.20% 0.030

n 64 63

female.PTArecoveryratesbetweengendersareincludedin

Table2.

Tinnitusoccurredin92.1%(n=117)ofcases.PTArecovery

rates for those with and without symptoms are shown in

Table3.Vertigowaspresentin52.8%(n=67)ofcases.PTA

recoveryrates werecomparedbetween patientswithand

withoutthissymptom,asshowninTable4.

TheresultsshowninTable5comparethedegreeofthe

initialhearinglosswithPTArecoveryrates.

Table4 IndependentStudent’st-testsbetweenpresence andabsenceofvertigoforrecoveryrates.

Vertigo t-test

No Yes p

Mean 25.83 21.70

n 60 67

Mean 47.69% 27.83%

n 60 67

Fig.1shows thepercentages of patientsachieving

sig-nificantimprovementintheirhearingacuity,separatedby

groupsofaffectedfrequencies.

Contralateralearhearinginvolvementwascomparedvs.

individualswithouthearingalterationintheircontralateral

ear,andtheresultsareshowninTable6.

Thetimeelapsedtotreatment,at differenttimes,and

theirrespectivecorrelationwithPTArecovery,areshownin

Table7.

Discussion

The word ‘‘prognosis’’, etymologically derived from the

Greek,means‘‘toknowbeforehand.’’Establishedasakey

conceptofmedicinebyHippocrates,8_the_act_of

prognostica-tiononlyisjustifiedifbased---inanecessaryandmandatory

way --- on a sufficient medical diagnosis. An apocryphal

phraseteaches:‘‘Therefore,thereisnocredibleprognosis

withoutdiagnosis.’’

Thus,achallengearisesindeterminingtheprognosisofa

diseaselikeISSHLthat,bydefinition,isanidiopathicevent.

Infact,ISSHLwouldbebetterlabeledasasymptomcommon

tomultiple diseases and,therefore,withdifferent

etiolo-gies ---and for each etiology,witha respectiveprognosis.

The interpretation and comparison of studies on

progno-sticfactorsinpatientswithISSHLstillconstituteadifficult

Table5 ANOVAtestsamonggradesofinitiallossforrecoveryrates.

Gradeofinitialloss ANOVA

Moderate Severe Profound p

Mean 20.29 23.60 25.88

Standarddeviation 17.45 25.20 27.59 0.546

n 34 37 52

Mean 48.21% 34.79% 28.76%

Standarddeviation 38.25% 37.10% 31.81% 0.046

n 34 37 52

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60%

% of patients

50% 50%

44.4%

25%

0% 40%

30%

20%

10%

0%

Low and middle Middle and high Low, middle, and high

Only high

Figure1 Distributionofsignificanthearingrecoverypercentagebygroupsofaffectedfrequencies.

Table6 IndependentStudent’st-testsbetween contralat-eralearhearingstatesforrecoveryrates.

Contralateralear t-test

Normal Changed p

Mean 25.70 11.22

n 109 18

Mean 39.78% 21.67%

n 109 18

and imprecise task, and there is no consensus regarding the actual influence of the factors studied in the clini-cal outcome of patients. Several prognostic factors have been studied in recent decades,with inconsistent results regardingtheindividualinfluenceofeachfactor.2,9---16

In the present study,there was nostatistically

signifi-cant differencefor improvementof PTArecovery rates in

those different age groups studied. However, there was

a trend of a better performance in age groups of 31---50

and 51---70 years. In extreme ages, absolute and relative

recoveryrateswerelowerthanthosefortheglobalsample.

A well designed eight-year prospective study found

simi-lar results, withpoorerhearing recovery inpatients aged

under 15years andabove60 years;that study attributed

these findings to a vulnerability of the immune system,

peculiar to extremes of age, as a probable explanation.2

Nakashima et al.17 _found _higher _rates _of _profound _losses

in children under14 years.Several studiesconsider older

ageasapoorprognosisfactorforhearingrecovery.11,13,18---20

It ispostulatedthat thecellulardegenerationinherentto

thenaturalprocessofaging,inassociationwithareduced

capacity for metabolic and cellular regeneration, have a

negativeinfluence.13_Other_studies,_however,_found_no_such

correlation.10,12,14

Nocorrelation was found between gender and hearing

recovery degree in this study, confirming the findings of

otherpublications.13,19,21

Tinnituswas present in 92.1% of patients, a very high

prevalence. This group of patients had statistically

sig-nificant higher rates of absolute and relative recovery

comparedtothegroupwithouttinnitus,corroborating

pre-viousstudies.10,22,23_It_is_assumed_that_presence_of_tinnitus

aftercochlearinjury wouldindicatethathair cellsremain

viable.24

Vertigowas present in 52.8% of subjects,who showed

lowerrelativerecoveryratescomparedtothegroup

with-out this symptom (p=0.002). It is well-established that

Table7 ANOVAtestsamonggroupsfortimeelapsedtotreatmentandrecoveryrates.

Timeelapsedtotreatment ANOVA

≤2days 2---7days 8---10days >10days p AbsolutePTArecovery

Mean 33.98 29.85 24.02 18.35

Standarddeviation 23.08 24.57 15.17 27.51 0.008

n 21 38 11 29

Mean 50.07% 48.51% 44.60% 24.49%

Standarddeviation 31.33% 39.27% 27.55% 34.35% 0.004

n 21 38 11 29

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vertigo is a factor for worse prognosis.2,3,9---11,13,14,18,22,23,25

A study analyzing 13 patients diagnosed with ISSHL with

and without vertigo revealed that those with losses in

high frequencies showed better recovery in the absence

of vertigo.17 _The _authors _concluded _that _the

inflamma-tory response located in the basal region of the cochlea

couldovercomethebarriersoftheanteriorlabyrinth,reach

thevestibuleandsemicircularcanalsandtriggervestibular

symptoms.

The relativerecoveryratewashigherfor patientswith

moderatevs.profoundloss,withstatisticalsignificance

dif-ference.Manystudiesconsidertheinitialdegreeofhearing

lossasanimportantprognosticfactor.Inpatientswitha

pro-nouncedinitialhearingloss,theworstaudiologicalresultis

expectedat the end offollow-up.2,3,9,10,20,22 _It_is _believed

thatincasesofprofoundloss,theextentofhaircellinjury

issoextensive,itdoesnotallowasignificantstructuraland

functionalrecovery.

Withtheindividualizationofhearingrecoveryby group

of affected frequencies, it was noted that high

frequen-cies, whenviewed in isolation,were not accompaniedby

asignificant hearingrecovery (Fig.1),while thelow- and

middle-frequencygroupsachievedbetterresults.Itshould

be borne in mind that most studies do not include this

differentiation by frequency, a fact which certainly

com-promisestheanalysisofresults.Itisestimatedthatabout

one-thirdto65%ofcasesofISSHLachievespontaneous

hear-ing recovery,1,3 _but _the _parameters_used_to_measure _such

improvement are, as a rule, speech reception threshold

(SRT),speechrecognitionthresholdindex(SRTI),andPTA,

which do not cover higher frequencies, especially 6 and

8kHz.

Subjectswithnormalcontralateralhearingshowed

abso-lute and relative recovery rates higher than those with

alteredcontralateral hearing,with statisticallysignificant

differenceforbothrates.Previousstudieswithlarger

sam-ples also concluded that altered contralateral hearing is

associatedwithaworseprognosis.2,10_It_is_believed_that_this

changeindicatessomepre-existingdysfunctionofthe

audi-torysystem,orofother systemsofthebody,thatreduces

thepotentialforrecovery.

Patientswhostartedtheirtreatmentbeforesevendays

had higher rates of absolute and relative recovery

com-pared topatients included in the categories above seven

and ten days(p=0.008), a resultsimilar toseveral other

studies.10,12---14,18,19,25 _There _was _no _{statistically} _significant

difference in recovery rates among patients who started

theirtreatmentwithin48handuptosevendays,suggesting

thattreatmentwithcorticosteroidshasthesame

effective-ness,ifstartedwithinsevendays.Inastudyof347subjects,

nobenefitwasnotedwithanearlyonsetoftreatment,

com-paringpatientswhostartedcorticosteroidswithintwodays

orbetweenthreeandsevendays.26

Conclusion

At thetimeof ISSHL onset,the followingvariables

corre-lated witha worse prognosis: dizziness, profound hearing

loss,changeincontralateralearhearing,andadelayedstart

oftreatment.PresenceoftinnitusatISSHLonsetcorrelated

withabetterprognosis.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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