BrazJOtorhinolaryngol.2016;82(6):650---653
www.bjorl.org
Brazilian
Journal
of
OTORHINOLARYNGOLOGY
ORIGINAL
ARTICLE
The
relationship
between
senile
hearing
loss
and
vestibular
activity
夽
Hanifi
Kurtaran
a,∗,
Baran
Acar
b,
Emre
Ocak
b,
Emre
Mirici
baTurgutOzalUniversityMedicalFaculty,DepartmentofOtorhinolaryngology,Ankara,Turkey bKeciorenTrainingandResearchHospital,DepartmentofOtorhinolaryngology,Ankara,Turkey
Received18September2015;accepted12November2015 Availableonline28February2016
KEYWORDS
Sensorineuralhearing loss;
Vestibular dysfunction; Puretone audiometry; Vestibularevoked myogenicpotentials
Abstract
Introduction:A considerable high number of SNHL patients also suffer from dizziness and relatedvestibularsymptoms.
Objective:Toevaluatetheassociationofvestibulardysfunctionandsensorineuralhearingloss (SNHL)inadultpatients.
Methods:Prospective,double-blinded,controlledstudiescomposedby63adultpatients with-outanyvestibularsymptomsordiagnosedvestibulardiseases.Audiologicalstatuswasmeasured withpuretoneaudiometryandthevestibularsystemwastestedwithvestibularevoked myo-genicpotential(VEMP).Patientsweredividedintotwo groups:astudy group(patientswith SNHL)andacontrolgroup(patientswithoutSNHL).VEMPresultsofthegroupswerecalculated andcompared.
Results:MeanP1(23.54)andN1(30.70)latencieswereprolongedinthestudygroup(p<0.001) andtheamplitudesofthestudygroupweresignificantlyreduced(p<0.001).Bothparameters oftheVEMPtestwereabnormalinthestudygroupwhencomparedtothecontrolgroup.
Conclusions:Thesefindingssuggestthatage-relatedSNHLmaybeaccompaniedbyvestibular weaknesswithoutanypossiblepredisposingfactorsforvestibulopathy.
© 2016Associac¸˜ao Brasileira de Otorrinolaringologiae CirurgiaC´ervico-Facial. Publishedby ElsevierEditoraLtda.ThisisanopenaccessarticleundertheCCBY-NC-NDlicense(http:// creativecommons.org/licenses/by-nc-nd/4.0/).
夽 Pleasecitethisarticleas:KurtaranH,AcarB,OcakE,MiriciE.Therelationshipbetweensenilehearinglossandvestibularactivity.Braz
JOtorhinolaryngol.2016;82:650---3. ∗Correspondingauthor.
E-mail:[email protected](H.Kurtaran).
http://dx.doi.org/10.1016/j.bjorl.2015.11.016
Vestibularactivityinsenilehearingloss 651
PALAVRAS-CHAVE
Perdaauditiva neurossensorial; Disfunc¸ãovestibular; Audiometriatonal; Potenciaisevocados miogênicos
vestibulares
Relac¸ãoentreperdaauditivasenileatividadevestibular
Resumo
Introduc¸ão: UmnúmeroconsideráveldepacientescomPANStambémsofredetonturase sin-tomasvestibularesrelacionados.
Objetivo: Avaliar a associac¸ão entre disfunc¸ão vestibular e perda auditiva neurossensorial (PANS)empacientesadultos.
Método: Estudoprospectivo,duplo-cegoecontroladocom63pacientesadultos,sem quais-quersintomasvestibularesoudoenc¸avestibulardiagnosticada.Aaudic¸ãofoiavaliadapormeio deaudiometriatonaleosistemavestibular,compotenciaisevocadosmiogênicosvestibulares (PEMV).Ospacientesforamdivididosemdoisgrupos:grupodeestudo(pacientescomPANS)e grupodecontrole(pacientessemPANS).OsresultadosdosPEMVdosgruposforamcalculados ecomparados.
Resultados: Aslatênciasmédias deP1(23,54)e N1(30,70)encontravam-seprolongadas no grupo deestudo(p<0,001),easamplitudesnogrupodeestudo estavamsignificantemente reduzidas (p<0,001).Ambos os parâmetrosdo teste dePEMV foramanormais nogrupo de estudoquandocomparadosaosdogrupocontrole.
Conclusões: NossasachadossugeremqueaPANSrelacionadaàidade podeseracompanhada porhipofunc¸ãovestibular,mesmonaausênciadepossíveisfatorespredisponentespara vestibu-lopatia.
©2016Associac¸˜ao BrasileiradeOtorrinolaringologiaeCirurgiaC´ervico-Facial.Publicado por Elsevier EditoraLtda. Este ´eum artigo Open Accesssob umalicenc¸a CC BY-NC-ND(http:// creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction
Sensorineuralhearingloss(SNHL)isthemostcommontype of sensorial deficiency, affecting over 360 million people acrosstheglobe,anditisconsideredapublichealth prob-lemregardlessoftheetiology.1Aconsiderablehighnumber ofSNHLpatientsalsosufferfromdizzinessandrelated ves-tibularsymptoms.Arelationshipisthereforehighlypossible betweenSNHLandvestibulardysfunction,intheabsenceof evidencesofanyinnerearorsystemicdiseasesthatcould causevestibulopathy.Manypatientspresentto otolaryngol-ogyclinicswithdizzinessandhearinglossproblemswithno obvious pathologyand arediagnosedwithpresbyacusis or age-relatedvestibulopathy.
This study aims to evaluate the relationship between the substructures of the vestibular system and the hear-ingorganswiththesameembryologicalorigin.Pathologies affectingonesubsideoftheinnerearmaythereforecause adysfunctioninthepartswiththesameembryological ori-gin.Fromthispointforthweinvestigatedthesacculeasa part of the vestibularsystem usingthe Vestibular Evoked MyogenicPotentials(VEMP)asitisoneofthemostaccurate andpracticalwaystoassesstheintegrityandfunctionofthe sacculeandinferiorvestibularnerve.The principleofthis diagnostictoolshedresultsfromtheselectiveactivationof vestibularnerveafferentsinnervatingthesaccule.Cervical VEMPresponsesarerecordedwithElectromyography(EMG) oftheSternocleidomastoid(SCM)muscleaftertheonsetof aclickstimulustotheexternalearcanal.2Itisabiphasic responsethatevaluatesthesacculocollicreflex.
Thenumberofrelevantstudiesislimitedascasereports constitute thevast majority of these papers.This lack of datamotivatedustosearchandseekformoreknowledge
abouttheseindistinctpatients.Inthisstudy,weinvestigated therelationship between SNHLandvestibular dysfunction inadultsbased onthehypothesis that themalfunction in onesubside,mayaffectthepartsofvestibularandhearing systemwiththesameembryologicalorigin.
Methods
A prospective, double-blinded, controlled study was con-ducted on adult patients. The study group consisted of patientsadmittedinourinstitutewithahearingloss com-plaint,diagnosedwithbilateralmoderatetosevereSNHL.A controlgroupwithsimilardemographicfeatureswasformed by healthy individuals without hearing loss. Patients with mixed types of hearing loss, external ear canal patholo-gies,perforatedtympanicmembrane,abnormalmiddleear functions,anykindofvascularordiagnosedneurological dis-eases,confirmedperipheralvestibulardiseases,orahistory ofotologicorlateralskullbasesurgerywereexcluded.
Pure Tone Audiometry (PTA) was evaluated using an AD629 Interacoustics® (Denmark, 2012) device in a sound proofroomtoscreenthehearingstatusofeachparticipant forthefrequencies 250---8000Hz.Apure tonethresholdin therangeof41---60dBHLwasconsideredasmoderateand 61---80dB HL as severe SNHL.3 Middle ear functions were evaluatedbytympanometryandacousticreflextesting.
652 KurtaranHetal.
andinstructedtoturntheirheadstowardthecontralateral sideofthetestedear.ThestateofcontractionofSCMwas equalizedbeforethestimulationbymeansofapreload con-trolsystem.TheEMGresponseofthemusclewasrecorded asbiphasicwaveformsaccordingtolatencies(P1 andN1) atastimuluslevelof95dBHL,500Hztoneburstwith4msn rise/falltimeand 2msn plateauwitha repetition rateof 5.5s.ThelatenciesandamplitudesofVEMPineachearwere calculatedforeachgroupandcompared.Theauditoryand vestibulartestingwereperformeddouble-blindedby sepa-rateresearchers.Informed consentwasobtained fromall subjects,andthisstudy wasapprovedby theinstitutional ReviewBoard(IRB682).
Statisticalmethods
Descriptivestatisticswereobtainedfromeachgroup;mean values,standarddeviations,andmedianswerecalculated. Fisher’sexact test andthe chi-squared test wereused to compareVEMPresultsbetweengroups.SPSS15.0for Win-dows (SPSSInc., Chicago,United States) was usedfor all statisticalanalyses,andap-value<0.05wasconsidered sta-tisticallysignificant.
Results
Intotal,63patientswithameanageof65.1years(min---max 55---82years)wereincludedinthestudy.Themeanageinthe studygroupwas67.2years,whileitwas64.2inthecontrol group(p>0.05).Therewere39femaleand24malepatients (p>0.05),withnopreponderanceintermsofgenderandage betweenthegroups.Thestudyandcontrolgroupsconsisted of 31 and 32 patients, respectively. Mean PTA value was 20.71dB(min---max10---25)inthecontrolgroupand63.53dB (min---max50---83)inthestudygroup(p<0.05).MeanP1and N1latenciesandamplitudesofthegroupsaresummarized inTable1.BothP1andN1latenciesweresignificantly pro-longed in the study group when compared tothe control group(p<0.001;Fig.1).The amplitudes werealso signifi-cantlyreducedinthestudygroup(p<0.001;Fig.2).
Discussion
The relationship betweenSNHL andthe vestibularsystem iscomplexandnotclearlyunderstood. Themechanism of theinteractionbetweentheauditoryandvestibularsystems in patients with SNHL remains to be discovered. Previ-ous studies have focused on the possibility of a relation between noise-induced hearing loss and impaired vesti-bularfunctions.4Inastudyamongpatientsdiagnosedwith
30.00
Mean P1&N1 latencies (ms) 25.00 20.00
15.00 10.00 5.00
0.00
Control group Study group
P1 Latency N1 Latency
Figure1 ComparisonofmeanP1andN1latenciesofthestudy andcontrolgroups.
120.00
100.00
80.00
60.00
40.00
20.00
0.00
Control group Mean P1&N1 amplitudes (
µ
V)
Study group
Figure2 MeanP1andN1amplitudesofthestudyandcontrol groups.
noise-inducedhearingloss,50%ofthesubjectshad abnor-malVEMPresults.5Inaddition,theanatomicalproximityof thesacculetothefootplateofthestapesmayhavea poten-tial rolein vestibulardysfunction,particularly in patients withahistoryofchronic noiseexposure.Inanotherstudy, Singhetal.6reportedapossiblerelationship,basedonthe significant reduction observed in the amplitudes of VEMP resultsinchildrenwithseveretoprofoundSNHL.
Froman embryological point of view, the saccule and cochlea develop fromthesameorigin in themembranous labyrinth, which is innervated by the inferior portion of the vestibularnerve.Furthermore,the sacculeacts asan acoustic-sensitive organ in lower species;7,8 therefore, as avestibular-sensitiveorgan,itcanbeconsideredasalate developmentinhumans.9,10
Manypatients with different types of presbycusis suf-ferfromvestibulardysfunction.Whetherthisvestibulopathy is due toage-related changes in the central nervous sys-tem or whether an association exists between SNHL and vestibular disease is unclear. Thus, in the present study, thegroupswereformedhomogenously,therebyeliminating anypossiblefactorsthatcouldcausevestibulardysfunction. TheprolongedP1andN1latencyperiodsandthereduction of the amplitudes observed in the study group suggested a peripheral vestibulardeficit in the patients withSNHL.
Table1 Meanvaluesoflatenciesandamplitudesinstudyandcontrolgroups.
Studygroup Controlgroup
Mean Mean pa
P1latency(ms) 23.54(17.71---32.18) 15.63(9.39---23.55) <0.001 N1latency(ms) 30.70(22.28---47.30) 23.48(19.07---31.98) <0.001 Amplitude(mV) 35.25(5---101) 97.02(12---196) <0.001
Vestibularactivityinsenilehearingloss 653
Thisresearchwasbasedonthehypothesisthatpathologies affectingonesubsideoftheinnerearmaycausea dysfunc-tionin the partswiththesame embryologicalorigin. Our findings suggest that SNHLmay beaccompanied by vesti-bular weakness,without anypossible predisposing factors forvestibulopathies.
Theweakpartofthisstudyisthelackofdataconcerning ocularVEMPandcanalreflectancewhichmaybean expres-sionofthe differencesintheglobal innerearimpairment thatoccurfromaging.Thecorrelationbetweenhearingloss andvestibulardysfunction maydepend onmultiple varia-bles.Thusfurtherstudieswithlargernumberofpatientsand supportedwithdifferenttypesofvestibularteststo evalu-atetheintegrityofvestibularsystemwillexpandawareness forthisissue.
AvastamountofpatientswithSNHL,regardlessthe eti-ology, have some degree of vestibular dysfunction. Apart from their diagnosis with peripheral vestibular diseases, mostofthesepatientsvisitdifferentdepartmentsincluding cardiology, internal medicine,geriatrics,or physical ther-apy and rehabilitation while seeking for the diagnosis of theirpathology.Manyotolaryngologistsalsoexaminethese patientsintheirdailyroutine.Inthelightofourresults,we canconcludethatdetailedinformationaboutthestatusof theinferiorportionofthevestibularsystem,inconjunction withauditoryfunctions,mayguidetheclinicianintheright directionforassessmentofthesepatients.
Conclusion
The findings suggest that age-related SNHL may be accompanied byvestibular weaknesswithout anypossible predisposingfactorsforvestibulopathy.
Conflict
of
interest
Theauthorsdeclarenoconflictsofinterest.
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