Braz. j. . vol.82 número4

www.bjorl.org

Brazilian

Journal

of

OTORHINOLARYNGOLOGY

ORIGINAL

ARTICLE

Subjective

visual

vertical

with

the

bucket

method

in

Brazilian

healthy

individuals

夽

Maristela

Mian

Ferreira

,

Fabiana

Cunha

,

Cristina

Freitas

Gananc

¸a

,

Maurício

Malavasi

Gananc

¸a

_,

_Heloisa

_Helena

_Caovilla

a_{PostgraduatePrograminHumanCommunicationDisorders,CampoFonoaudiológico,EscolaPaulistadeMedicina,Universidade}

FederaldeSãoPaulo(EPM-UNIFESP),SãoPaulo,SP,Brazil

b_{OtorhinolaryngologicalSciences,EscolaPaulistadeMedicina,UniversidadeFederaldeSãoPaulo(EPM-UNIFESP),SãoPaulo,SP,}

Brazil

c_{Sciences,EscolaPaulistadeMedicina,UniversidadeFederaldeSãoPaulo(EPM-UNIFESP),SãoPaulo,SP,Brazil}

d_{SchoolofSpeechTherapyandAudiologySpecialization,EscolaPaulistadeMedicina,UniversidadeFederaldeSãoPaulo}

(EPM-UNIFESP),SãoPaulo,SP,Brazil

e_{Otorhinolaryngology,EscolaPaulistadeMedicina,UniversidadeFederaldeSãoPaulo(EPM-UNIFESP),SãoPaulo,SP,Brazil} f_{DisciplineofOtologyandNeurotology,EscolaPaulistadeMedicina,UniversidadeFederaldeSãoPaulo(EPM-UNIFESP),São}

Paulo,SP,Brazil

Received24May2015;accepted26August2015 Availableonline2February2016

KEYWORDS

Ear;

Posturalbalance; Otolithicmembrane

Abstract

Introduction:Thecapacityofahealthyindividualtoestimatethetrueverticalinrelationto theEarthwhenafluorescentlineisalignedinacompletelydarkroomiscalledthesubjective visualvertical.

Objective:ToevaluatesubjectivevisualverticalusingthebucketmethodinhealthyBrazilian individuals.

Methods:Binocular subjective visual vertical was measured in 100 healthy volunteers, 50 femalesand50males.Thevolunteersindicatedtheestimatedpositioninwhichafluorescent lineinsideabucketreachedtheverticalposition.Atotaloftenrepetitionswereperformed, fiveclockwiseandfivecounterclockwise.Dataweretabulatedandanalyzedstatistically.

Results:Itwasobservedthatthehighestconcentrationofabsolutevaluesofverticaldeviation waspresentupto3◦_{,regardlessofgender,andtheverticaldeviationdidnotincreasewithage.}

Theanalysisofthemeanoftheabsolutevaluesofdeviationsfromtheverticalof90%ofthe sampleshowedamaximumvalueof2.6◦_{,andattheanalysisof95%,themaximumvaluewas}

3.4◦_{deviationfromthevertical.}

夽 _{Pleasecitethisarticleas:FerreiraMM,CunhaF,Gananc¸aCF,Gananc¸aMM,CaovillaHH.Subjectivevisualverticalwiththebucketmethod}

inBrazilianhealthyindividuals.BrazJOtorhinolaryngol.2016;82:442---6. ∗_{Correspondingauthor.}

E-mail:maristelamian@yahoo.com.br(M.M.Ferreira).

http://dx.doi.org/10.1016/j.bjorl.2015.08.027

Conclusion: Thebucketmethodiseasytoperformandinterpretwhenassessingthedeviation ofthesubjectivevisualverticalinrelationtothetrueverticalinhealthyBrazilianindividuals. © 2016 Associac¸˜ao Brasileira de Otorrinolaringologia e Cirurgia C´ervico-Facial. Published by Elsevier Editora Ltda. This is an open access article under the CC BY license (http://

creativecommons.org/licenses/by/4.0/).

PALAVRAS-CHAVE

Orelha;

Equilíbriopostural; Membranaotolítica

Verticalvisualsubjetivacomométododobaldeemindivíduosbrasileiroshígidos

Resumo

Introduc¸ão: Acapacidadequeum indivíduohígido tememestimaraverticalverdadeiraem relac¸ãoàTerra,quandoalinhaumalinhafluorescenteemumasalacompletamenteescuraé denominadadeVerticalVisualSubjetiva(VVS).

Objetivo: AvaliaraVVScomométododobaldeemindivíduosbrasileiroshígidos.

Método: AVVSbinocularfoimedidaem100voluntárioshígidos,50dogênerofemininoe50 do masculino. Osvoluntários indicaram aposic¸ãoestimada em queuma linha fluorescente no interiordeum balde alcanc¸ou aposic¸ão vertical.Foramrealizadas 10 repetic¸ões,cinco nosentidohorárioecinconoanti-horário.Osdadosforamtabuladosesubmetidosàanálise estatística.

Resultados: Observou-sequeamaiorconcentrac¸ãodosvaloresabsolutosdosdesviosdavertical estevepresenteaté3◦_{,independentedogêneroeodesviodaverticalnãoaumentouconforme}

aidade.Àanálisedamédiadosvaloresabsolutosdosdesviosdaverticalde90%daamostra, foiencontradoovalormáximode2,6◦_{eàanálisede95%ovalormáximofoide3,4}◦_dedesvio

davertical.

Conclusão:Ométododobaldeéfácilderealizaredeinterpretarnaavaliac¸ãododesvioda verticalvisualsubjetivaemrelac¸ãoàverticalverdadeiradeindivíduosbrasileiroshígidos. © 2016 Associac¸˜ao Brasileira de Otorrinolaringologia e Cirurgia C´ervico-Facial. Publicado por Elsevier Editora Ltda. Este ´e um artigo Open Access sob uma licenc¸a CC BY (http://

creativecommons.org/licenses/by/4.0/).

Introduction

The inner ear, also called the labyrinth, can be divided into anterior labyrinth, which contains the hearing organ (cochlea) and posterior labyrinth, comprising the three semicircular canals (lateral, superior, and posterior) and the vestibularsystem, which includes theutricle and the saccule.1_{Theinnerearvestibularsystemreceptorsconsist} oftwotypesof structures:onecupula-endolymphatic sys-temin the threesemicircularcanals, sensitive toangular accelerations,andanamalgamofotolithswithina viscoelas-tic membrane at the level of the utricular and saccular macula,sensitivetolinearaccelerations.1_{Concomitantwith} informationfromthevisualandproprioceptivesystems,the corticalotolithafferentsalsoparticipateinspatial orienta-tion,motionperception,thementalrepresentationof the bodyinspace,1_{andtheperceptionofverticality.}2,3

Theabilitytojudgewhethertheobjectsareinthe ver-ticalpositioniscalledsubjectivevisualvertical(SVV).

Inahealthyindividual,theotolithorgansalonecan con-struct the SVV, evenin casesof deprivation of visual and proprioceptivestimuli;inunilateralvestibulardysfunction, therecoveryofSVVseemstobeassociatedwiththe possi-bilityofeffectivelyusingproprioceptiveandexteroceptive information,particularlythoseoftheplantarsurface.4

Thebucketmethod,theobjectofourresearch,was ini-tiallydesigned5_{andthencompared}6_{withthesophisticated} andstandardizedhemisphericdomemethod,7_showingthat

thedistributionofSVVvalueswassimilarforthetwo meth-ods,thusdemonstratingthatthebucketmethodcanbecome partofroutineclinicalexaminations,asitisinexpensiveand easytoperform.

Inthedomemethod,ahemisphericdomecoveredwith coloreddotsandalineartargetisrotatedrandomlyandthe individualisinstructed toalignthetargetthroughavideo gamecontrol,makingitasverticalaspossible;inthebucket method, a bucket is rotated and the individual indicates whenafluorescentstraightlinedisplayedintheinferiorand innerpartofthebucketreachesaverticalposition.6_Inthe bucketmethod,therangeofabsolutedeviationsoftheSVV valuesinrelationtothetrueverticalinhealthysubjectswas 0.9±0.7◦_{(mean±standarddeviation);nosignificanteffect}

ofageorgenderwasidentified.6

Anotherstudyindicatedthatthebucketmethodisuseful todescribespatialdeficitsinpatientswithprovenvestibular disorder,butnotasascreeningtest.In50healthysubjects, themean(standarddeviation,minimum/maximum)ofthe absolutevaluesofverticaldeviationwas1.2◦_(0.7;0◦_/3.2◦₎

forfemales;and1.0◦_(0.8;0◦_/2.7◦_)formales.8

InBrazil,SVVwasevaluatedin30healthyBrazilian indi-vidualsby adjusting a virtual line in the verticalposition withacomputermouse,projectedonawhitescreen.The meandeviationofSVVwas−0.372◦_{±1.21;representingsix}

repetitions.9

fluorescentlight,positionedinfrontoftheindividualsandat theleveloftheireyes.Theassessedindividualsworeglasses withlight-filteringlensesthatmadeanyothervisual affer-entinformationimpossible,withtheexceptionofthe fluo-rescentlight,perceivedasagreenline.TenSVVadjustments weremade,oneforeachside,totalingfiveintheclockwise andfiveinthecounterclockwisedirection.Theangular incli-nationsofthevertical positionweremeasured indegrees anddefinedaspositivefor clockwiseandnegativeforthe counterclockwisedeviations,inrelationtothepatient.The resultsofSVVshowedthemeanvaluesoftenadjustments, rangingbetween−2.0◦_and+2.4◦_{(mean=0.18,SD=0.77).}10 Severalstudieshaveshowntheimportanceofvestibular assessmentbySVVwithdifferentmethods,andalsowiththe bucketmethod.However,toapplythismethodinBrazil,it isimportanttoknowthebehaviorofhealthyBrazilian indi-viduals,forsubsequentcomparisonwithpatientswhohave vestibulardisorders.Consideringthesemiological valueof theSVVassessmentandthescarcityofnationalstudiesusing thebucketmethod,whichisinexpensiveandeasytoapply, itwasdecidedtoperformthisinvestigation.

The objectiveof thisstudywastoassesstheSVV using thebucketmethodinhealthyBrazilianindividuals.

Methods

This study wasperformed after approval by the Research Ethics Committee of the institution under protocol No. 51439/12.

Thesampleofthiscross-sectionalstudyconsistedof100 healthy adult volunteer individuals from the community, 50females and50males,withnocomplaintsofvestibular disorders and/or hearing loss; individuals with cognitive impairment,severevisualacuityalteration,andhistoryof neurologicaldiseasewereexcluded.

The SVV evaluation wasperformed using a bucket, as wellasinexpensiveandeasilyacquiredmaterials:anopaque plasticbucket,withaborderlargerthan25cm,cardboard, string,fluorescenttape,weights(screwnuts),andadhesive tape.Apieceoffluorescenttape,placedverticallyonthe innersideofthebottomofthebucket,wasperfectlyaligned withthezeromarkofaprotractorpositionedontheexternal andinferiorpartofthebucket,andbothwerealignedwith thetrueverticalinrelationtotheEarth11 _{(Figs.1and2).}

The SVV wasmeasured binocularly. The healthy volun-teerswere asked to look at a fluorescent line inside the bucket,inthesittingposition,withtheirheadsup6_(Fig.3). Insomecases,whenitwasimpossibleforthevisualfieldto becompletelyinsidethebucket,thevolunteer’sheadand thebucketwerecoveredwithadarkclothtopreventvisual cues(Fig.4).

To measure the SVV, thebucket wasrandomly rotated by the examiner, to exclude possible tactile cues, in the clockwiseorcounter-clockwisedirections,toafinalposition around15◦_{,andthenslowlyrotatedtowardthezerodegree}

position.The volunteers indicated the estimated position where thefluorescent line hadreached the vertical posi-tion,asking the examiner to stop moving the bucket, by saying‘‘stop’’.Tenrepetitionsoftheprocedurewere per-formed,fiveintheclockwiseandfiveintheanti-clockwise direction;theidentifiedvalueswererecordedinthedegree

Figure1 Viewofthefluorescenttapeonthebottomofthe insideofthebucket.

Figure2 Viewoftheoutsideandbottomofthebucket.

scale on the outside of the bucket. The angular inclina-tionsoftheverticalpositionweremeasuredindegreesand definedaspositivedeviationsintheclockwiseandnegative intheanti-clockwisedirection,inrelationtothevolunteer. Theprocedurewasrepeatedwhentheexaminermovedthe buckettoofast,withoutgivingthepatientenoughtimefor theresponse.

Figure3 Applyingthebucketmethod.

Figure4 Applyingthebucketmethodusingadarkcloth.

(˛=0.05)andSPSSv.19forWindowsandOfficeExcel2007

wereusedinthestatisticalanalysis.

Results

Atotalof100healthyvolunteerswasevaluated,50females and50males,agedbetween18and59years,withno com-plaintsofvestibulardisordersand/orhearingloss.

Table1showsthemean,median,standarddeviation,and minimumandmaximumvaluesofthemeanoftheabsolute valuesofdeviationsfromtheverticaloftenrepetitionsin the50femaleandmalevolunteers.

Fig.5representsthemeanoftheabsolutevaluesof devi-ationsfromtheverticalregardingageandgender.Itcanbe observed that the highest concentrationof values can be found upto3◦ _{of verticaldeviation,regardless ofgender,}

Table1 Measurements---summary ofabsolute valuesof deviationsfromthevertical,accordingtogenderand statis-ticalcomparison.

Deviationsfromvertical Femalegender Malegender

n 50 50

Mean 2.02 1.66

Median 2.00◦ _1.65

Minimumvalue 0.4 0.6

Maximumvalue 4.1 3.4

Standarddeviation 0.8042 0.6386

pa _0.026

a _{Mann---Whitneytest.}

angular de

viation (Gr

aus)

age (years) 5

4

3

2

1

0

10 15 20 25 30 35

95%

90%

50%

40 45 50 55 60

Figure5 Two-dimensionalscatterplotandthe50%,90%,and 95%percentilesofthemeanoftheabsolutevaluesofdeviations fromthe vertical (degrees)andtheage (years) accordingto gender(+female/male).

andthattheverticaldeviationdoesnotincreasewithage. Theanalysisofthemeanoftheabsolutevaluesofdeviations fromtheverticalof90%ofthesampleshowedamaximum valueof2.6◦ _{andthe95%analysisfoundamaximumvalue}

of3.4◦_{ofdeviationfromvertical.}

Discussion

SVVassessmentisasimpletechniquetostudyotolith func-tion,asthe inclinationofthe fluorescentline beyondthe valuesconsidered tobe normal is the most sensitive sign of vestibularsystem dysfunction; the buckettest is inex-pensiveandeasytoperform;theanalysisof theresultsis simple,thetestisfastandreliable,anditcanbeapplied anywhere,warrantingitsbroaduse.6

ofdeviations fromthevertical infemale andmale volun-teers,similartopreviousreportsintheliterature.8

Theoriginalstudyusingthebucketmethoddidnot iden-tify an effect of gender and age on the deviation from the vertical.6 _{However, according to the two-dimensional} scatterplotgraph,thesamplecanbeconsidered homoge-nousregardinggenderandage,andwhen90%ofthesample wasanalyzed,thevalueswerefoundupto2.6◦_,or

approxi-mately3◦_{,asthebucketmethodidentifiesangulardeviation}

valuesinwholenumbers.Thevalueof2.6◦_{issimilartothe}

valueof 2.3◦ _{found in theoriginal study usingthebucket}

method.6 _{Another study,}12 _{assessing the performance of} healthy elderly individuals, adopted a deviation of 3◦ _as

thenormallimit,similartothatofthepresentstudy,also making an approximation of the standard values used as reference.6

The SVV was evaluatedin healthy Brazilian individuals through other methods that identified values similar to that found in this study; the mean deviation from SVV was−0.372±1.21◦ _{withthemethodthatusedacomputer}

mousetoadjustavirtualline inthevertical position pro-jected on a white screen,9 _{and it ranged between}

−2.0◦

and+2.4◦ _{inanotherstudythatusedaportablestickwith}

fluorescentlight.10

As previously noted,6,13 _{the authors also believe that} an easy-to-perform and easy-to-interpret SVV evaluation shouldbeincludedinroutineclinicalvestibulartests,asit canprovideinformationontheotolithorganfunctionand also can monitor changes and responses to treatment in patientswithcentralorperipheralvestibulardisorders.

TheaimofthisstudywastoevaluateSVVusingthebucket methodinhealthyBrazilianindividualswithnoauditoryand vestibularcomplaints. It is hoped that these findings uti-lizing this method may be useful in clinical practice and infuture studies,in orderto help characterize vestibular systemdysfunctioninpatientswithbodybalancedisorders.

Conclusion

Thebucketmethodiseasytoperformandinterpretwhen evaluatingthedeviationoftheSVVinrelationtotrue ver-ticalinhealthyBrazilianindividuals.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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