vertigo and the vestibular system

Testing Vestibular Testing Vestibular FunctionFunction

Dr.saied alhabashDr.saied alhabash

Testing Vestibular FunctionTesting Vestibular Function

Four percent of patients18-65 yo visit clinic Four percent of patients18-65 yo visit clinic with complaint of “dizziness”with complaint of “dizziness”

Three percent consider it “Severely Three percent consider it “Severely incapacitating”incapacitating”

Third most common complaint in elderlyThird most common complaint in elderly

Testing Vestibular FunctionTesting Vestibular Function

Otolaryngologist is considered balance Otolaryngologist is considered balance specialistspecialist

Private practice physicians often quoted Private practice physicians often quoted “I wish I knew more about dizzy patients”“I wish I knew more about dizzy patients”

ObjectivesObjectives

Describe office examinations of dizzy Describe office examinations of dizzy patientspatients

Describe vestibular function studiesDescribe vestibular function studies Review indications for vestibular function Review indications for vestibular function

studies studies Review efficacy of office and vestibular Review efficacy of office and vestibular

function studies function studies

Classification Classification

cranial nerve evaluationcranial nerve evaluation Positional tests Positional tests Postural control testPostural control test Oculomotor function testOculomotor function test

Cranial nerve evaluation Cranial nerve evaluation

88 77 3,4,6(before ENG)3,4,6(before ENG)

Positional tests Positional tests

DynamicDynamic Dix-HallpikeDix-Hallpike visual acuity testvisual acuity test StaticStatic (ENG)(ENG)

Dix-Hallpike ManeuverDix-Hallpike Maneuver Used to provoke nystagmus and vertigo Used to provoke nystagmus and vertigo

commonly associated with BPPVcommonly associated with BPPV Head turned 45 degrees to maximally Head turned 45 degrees to maximally

stimulate posterior semicircular canalstimulate posterior semicircular canal Head supported and rapidly placed into head Head supported and rapidly placed into head

hanging positionhanging position Frenzel glasses eliminate visual fixation Frenzel glasses eliminate visual fixation

suppression of responsesuppression of response

Dix-Hallpike ManeuverDix-Hallpike Maneuver

Dix-Hallpike ManeuverDix-Hallpike Maneuver

Positive testPositive test Up-beating nystagmusUp-beating nystagmus Nystagmus to the stimulated sideNystagmus to the stimulated side Rotary component to the affected earRotary component to the affected ear Lasts 15-45 secondsLasts 15-45 seconds Latency of 2-15 secondsLatency of 2-15 seconds Fatigues easilyFatigues easily

Dynamic Visual AcuityDynamic Visual Acuity

Used for bilateral vestibular weaknessUsed for bilateral vestibular weakness Visual acuity checked on Snellen chartVisual acuity checked on Snellen chart Rechecked while rotating head back and Rechecked while rotating head back and

forth at 1-2 Hz.forth at 1-2 Hz. Loss of 2-3 lines considered abnormalLoss of 2-3 lines considered abnormal

Postural control testPostural control test

Romberg test Romberg test Fukoda stepping testFukoda stepping test Tandem gait testTandem gait test Pastpointing testPastpointing test

Romberg TestRomberg Test

Patient asked to stand with feet together Patient asked to stand with feet together and eyes closedand eyes closed

Fall or step is positive testFall or step is positive test Equal sway with eyes open and closed Equal sway with eyes open and closed

suggests proprioceptive or cerebellar sitesuggests proprioceptive or cerebellar site More sway with eyes closed suggests More sway with eyes closed suggests

vestibular weaknessvestibular weakness

Romberg TestRomberg Test

Fukuda Stepping TestFukuda Stepping Test Originally described by Fukuda using 100 steps Originally described by Fukuda using 100 steps

on a marked floor.on a marked floor. Patients are asked to step with eyes closed and Patients are asked to step with eyes closed and

hands out in fronthands out in front Rotation by more than 45 degrees is abnormalRotation by more than 45 degrees is abnormal Rotation usually occurs to the side of the lesionRotation usually occurs to the side of the lesion Rotation often found in asymptomatic patientsRotation often found in asymptomatic patients

Dysdiadochokinesia Dysdiadochokinesia Testing(pastpointing test)Testing(pastpointing test)

Most commonly tested with the hand Most commonly tested with the hand slapping testslapping test

Abnormalities seen in patients with Abnormalities seen in patients with cerebellar dysfunctioncerebellar dysfunction

Poor sensitivity and specificityPoor sensitivity and specificity

Tandem Gait TestTandem Gait Test Patients are asked to walk heal to toe in a Patients are asked to walk heal to toe in a

straight line or in a circlestraight line or in a circle Complex function evaluates many aspects Complex function evaluates many aspects

of balanceof balance Poor performance seen in cerebellar Poor performance seen in cerebellar

lesions, but can be seen in many disorderslesions, but can be seen in many disorders Poor sensitivity and specificityPoor sensitivity and specificity Normal: more than 10step without Normal: more than 10step without

deflectiondeflection

Oculomotor function testsOculomotor function tests Fistula testing(pneumatic otoscopy)Fistula testing(pneumatic otoscopy) Nonlineary testingNonlineary testing Nystegmus testing Head-shaking test Nystegmus testing Head-shaking test

Head-thrust testHead-thrust test spontaneous nystagmusspontaneous nystagmus gaze nystagmusgaze nystagmus

Pneumatic OtoscopyPneumatic Otoscopy

Positive and negative pressure applied to Positive and negative pressure applied to middle earmiddle ear

Hennebert’s sign/symptom – nystagmus Hennebert’s sign/symptom – nystagmus and vertigo with pressure, alternates with and vertigo with pressure, alternates with positive and negative pressurepositive and negative pressure

Can be present in patients with Can be present in patients with perilymphatic fistula, syphilis, Meninere’s perilymphatic fistula, syphilis, Meninere’s disease, SCC dehiscence syndromedisease, SCC dehiscence syndrome

Head Thrust TestHead Thrust Test Inhibitory response not as robust as the Inhibitory response not as robust as the

stimulatory response to stimulate VORstimulatory response to stimulate VOR Movements that overcome the inhibitory Movements that overcome the inhibitory

response of vestibule will result in VOR lagresponse of vestibule will result in VOR lag Head tilted 30 degrees Head tilted 30 degrees Rapid head movements to either side with focus Rapid head movements to either side with focus

on examiner’s noseon examiner’s nose Patients have catch-up saccade when rotated to Patients have catch-up saccade when rotated to

side of weaknessside of weakness Sensitivity 75%, Specificity of 85% Sensitivity 75%, Specificity of 85%

Head Shake NystagmusHead Shake Nystagmus

Evaluates unilateral vestibular weaknessEvaluates unilateral vestibular weakness Head tilted back 30 degreesHead tilted back 30 degrees Shake back and forth for 30 seconds as Shake back and forth for 30 seconds as

quickly as possiblequickly as possible Unilateral vestibular deficit causes slow Unilateral vestibular deficit causes slow

phase nystagmus to the side of lesionphase nystagmus to the side of lesion Low sensitivity (27%) Low sensitivity (27%) Good specificity (85%)Good specificity (85%)

Nonlineary testingNonlineary testing

Gaze nystagmusGaze nystagmus

Central origin nystagmusCentral origin nystagmus Peripheral origin nystagmusPeripheral origin nystagmus

Quantitative Vestibular Quantitative Vestibular Testing(static positional tests) Testing(static positional tests)

indicationsindications Diagnosis unclearDiagnosis unclear Prolonged symptoms unresponsive to Prolonged symptoms unresponsive to

conservative treatmentconservative treatment Screen for central disordersScreen for central disorders Evaluate prior to surgical ablation Evaluate prior to surgical ablation

proceduresprocedures Documentation of vestibular deficitsDocumentation of vestibular deficits

Electronystagmography (ENG)Electronystagmography (ENG)

Divided into oculomotor tests, positional Divided into oculomotor tests, positional and positioning tests, and caloric testsand positioning tests, and caloric tests

Only vestibular test with the ability to test Only vestibular test with the ability to test individual labyrinths separatelyindividual labyrinths separately

Relies on the vestibulo-ocular reflex (VOR) Relies on the vestibulo-ocular reflex (VOR) to test the peripheral vestibular functionto test the peripheral vestibular function


Oculomotor testsOculomotor tests Positional testsPositional tests Caloric tests Caloric tests


Oculomotor testsOculomotor tests All test eye movements that originate in the All test eye movements that originate in the

cerebellumcerebellum Saccadic trackingSaccadic tracking Smooth pursuit trackingSmooth pursuit tracking Optokinetic testingOptokinetic testing

Oculomotor TestsOculomotor Tests

Saccadic trackingSaccadic tracking Patients concentrates on a randomly moving Patients concentrates on a randomly moving

targettarget Latency – difference in time between Latency – difference in time between

movement of object and eye (150-250 ms)movement of object and eye (150-250 ms) Velocity – speed of saccade 200-400 Velocity – speed of saccade 200-400

degrees/second low end of normaldegrees/second low end of normal Accuracy – amount of undershoot/overshoot Accuracy – amount of undershoot/overshoot

of target (75-120%) of target (75-120%)

Saccadic TrackingSaccadic Tracking

Smooth Pursuit TestSmooth Pursuit Test

Tests ability to accurately and smoothly Tests ability to accurately and smoothly pursue a targetpursue a target

Gain of eyes compared to movement of Gain of eyes compared to movement of targettarget

Saccade movements eliminated from Saccade movements eliminated from calculationscalculations

Asymmetrical pursuit highly suggestive of Asymmetrical pursuit highly suggestive of central disorderscentral disorders

Optokinetic TestsOptokinetic Tests

Vestibular system and optokinetic Vestibular system and optokinetic nystagmus allow steady focus on objectsnystagmus allow steady focus on objects

Target is rapidly passed in front of subject Target is rapidly passed in front of subject in one direction, then the otherin one direction, then the other

Eye movements are recorded and Eye movements are recorded and compared in each directioncompared in each direction

Asymmetry suggestive of CNS lesionAsymmetry suggestive of CNS lesion High rate of false positive resultsHigh rate of false positive results

Smooth Pursuit and Smooth Pursuit and Optokinetic TestsOptokinetic Tests

Smooth Pursuit TestSmooth Pursuit Test

Smooth Pursuit and Smooth Pursuit and Optokinetic TestsOptokinetic Tests

Positional and Positioning TestingPositional and Positioning Testing

Positional test Positional test Insults to vestibular system are compensated by Insults to vestibular system are compensated by

stimulationstimulation Maximal compensation in head up positionMaximal compensation in head up position Tests for nystagmus in static head positionsTests for nystagmus in static head positions Vertical or direction changing nystagmus suggests Vertical or direction changing nystagmus suggests

central disordercentral disorder Positioning testPositioning test

Used to determine presence of BPPVUsed to determine presence of BPPV Quantitative Dix-Hallpike maneuverQuantitative Dix-Hallpike maneuver

Caloric TestingCaloric Testing

Established and widely accepted method Established and widely accepted method of vestibular testingof vestibular testing

Most sensitive test of unilateral vestibular Most sensitive test of unilateral vestibular weaknessweakness

Patient positioned 30 degrees from prone Patient positioned 30 degrees from prone (HSCC vertical allowing max stim)(HSCC vertical allowing max stim)

Cold and warm water/air flushed into EACCold and warm water/air flushed into EAC

Caloric TestingCaloric Testing

COWS (cold opposite, warm same) – COWS (cold opposite, warm same) – direction of the nystagmusdirection of the nystagmus

Stimulation in 0.002-0.004 Hz range Stimulation in 0.002-0.004 Hz range (Head movements in 1-6 Hz range)(Head movements in 1-6 Hz range)

Visual fixation should reduce strength of Visual fixation should reduce strength of caloric responses 50-70%caloric responses 50-70%

% caloric paresis = 100 * [(LC + LW) – % caloric paresis = 100 * [(LC + LW) – (RC + RW)/(LC + LW + RC + RW)](RC + RW)/(LC + LW + RC + RW)]

Rotational Chair TestingRotational Chair Testing ““Gold standard” in identifying bilateral vestibular Gold standard” in identifying bilateral vestibular

lesionslesions Used to monitor for progressive bilateral Used to monitor for progressive bilateral

vestibular loss (gentamicin toxicity)vestibular loss (gentamicin toxicity) Used to quantify bilateral vestibular loss – Used to quantify bilateral vestibular loss –

vestibular rehab vs. balance trainingvestibular rehab vs. balance training Useful in testing children that will not allow Useful in testing children that will not allow

caloric irrigationscaloric irrigations Used with borderline caloric tests when water Used with borderline caloric tests when water

calorics cannot be used calorics cannot be used

Rotational Chair TestingRotational Chair Testing


Sinusoidal Harmonic Acceleration TestSinusoidal Harmonic Acceleration Test Most commonly performedMost commonly performed Rotates patients at frequencies from 0.01-Rotates patients at frequencies from 0.01-

1.28 Hz1.28 Hz Unilateral lesions have gain and phase Unilateral lesions have gain and phase

asymmetries to the affected sideasymmetries to the affected side Reduced gain across all frequencies or phase Reduced gain across all frequencies or phase

leads suggests bilateral vestibular lesionsleads suggests bilateral vestibular lesions


Kaplan et al.Kaplan et al. 198 adults tested198 adults tested 29 patients with bilateral loss by chair testing29 patients with bilateral loss by chair testing 25/29 with bilateral caloric weakness by ENG25/29 with bilateral caloric weakness by ENG 3/29 with unilateral caloric weakness by ENG3/29 with unilateral caloric weakness by ENG 3/45 patients with unilateral caloric weakness 3/45 patients with unilateral caloric weakness

by ENG had abnormal chair testsby ENG had abnormal chair tests

PosturographyPosturography

Used to tests integration of balance Used to tests integration of balance systemssystems

Useful in quantification of fall riskUseful in quantification of fall risk Most useful in following conditions:Most useful in following conditions:

Chronic disequilibrium and normal examsChronic disequilibrium and normal exams Suspected malingeringSuspected malingering Suspected multifactorial disequilibriumSuspected multifactorial disequilibrium Poorly compensated vestibular injuriesPoorly compensated vestibular injuries


5/6 – Vestibular dysfunction5/6 – Vestibular dysfunction 2,3,5,6 – somatosensory and vestibular dysfunction2,3,5,6 – somatosensory and vestibular dysfunction 3,6 – visual preference3,6 – visual preference 1,2,3,4 or any combination with normal 5/6 - aphysiologic1,2,3,4 or any combination with normal 5/6 - aphysiologic

Vestibular Evoked Myogenic Vestibular Evoked Myogenic Potentials (VEMP’s)Potentials (VEMP’s)

Utricle and saccule detect linear Utricle and saccule detect linear accelerationacceleration

Saccule slightly responsive to sound do to Saccule slightly responsive to sound do to its position near the oval windowits position near the oval window

VEMP’s stimulate the saccule and record VEMP’s stimulate the saccule and record EMG output in the SCMEMG output in the SCM


Clicks or tones presented Clicks or tones presented to the ear stimulate to the ear stimulate saccule, inferior saccule, inferior vestibular nerve, vestibular nerve, vestibular nucleus, medial vestibular nucleus, medial vestibulospinal tract, vestibulospinal tract, accessory nucleus, accessory nucleus, cranial nerve XIcranial nerve XI

EMG of SCM records EMG of SCM records output after click output after click stimulation of earstimulation of ear

Allows unilateral testingAllows unilateral testing


VEMP’s may be absent in patients with VEMP’s may be absent in patients with vestibular neuritisvestibular neuritis

Patients with lower threshold VEMP’s and a Patients with lower threshold VEMP’s and a conductive hearing loss same side may have conductive hearing loss same side may have SCC dehiscence syndromeSCC dehiscence syndrome

Absent in bilateral vestibular loss in Absent in bilateral vestibular loss in aminoglycoside ototoxicityaminoglycoside ototoxicity

VEMP‘s show higher thresholds and are absent VEMP‘s show higher thresholds and are absent in patients with Meniere’s diseasein patients with Meniere’s disease

Absent in acoustic neuromasAbsent in acoustic neuromas May be used in failed vestibular nerve sectionMay be used in failed vestibular nerve section

Dr. Peltier’s Dizzy EvaluationDr. Peltier’s Dizzy Evaluation History – will give diagnosis in majority of disordersHistory – will give diagnosis in majority of disorders PhysicalPhysical

Head and Neck Exam Head and Neck Exam Spontaneous nystagmus on trackingSpontaneous nystagmus on tracking

• Vertical or direction changing nystagmus = Vertical or direction changing nystagmus = MRI and neurology referral MRI and neurology referral

Pneumatic OtoscopyPneumatic Otoscopy• If positive If positive consider consider diagnosis of fistula, Meninere’s, syphilisdiagnosis of fistula, Meninere’s, syphilis

Dix HallpikeDix Hallpike• If positive, Eply maneuver twice, if still dizzy, ENGIf positive, Eply maneuver twice, if still dizzy, ENG

Head thrust test alone or with head shake nystagmus Head thrust test alone or with head shake nystagmus • If positive, start vestibular exercisesIf positive, start vestibular exercises• If no response - ENGIf no response - ENG

Rhomberg Test Rhomberg Test • If equal sway with eyes closed and open neurology referral, ENGIf equal sway with eyes closed and open neurology referral, ENG

Dr. Peltier’s Dizzy EvaluationDr. Peltier’s Dizzy Evaluation• Fukuda stepping test if suspected vestibular Fukuda stepping test if suspected vestibular

dysfunction and normal head shake/head thrust dysfunction and normal head shake/head thrust tests, or proceed to ENGtests, or proceed to ENG

• Orthostatic measurements if directed by historyOrthostatic measurements if directed by history• Dynamic visual acuity if possibility of bilateral lossDynamic visual acuity if possibility of bilateral loss

AudiogramAudiogram• Obtain in every dizzy patient. Cost effective exam Obtain in every dizzy patient. Cost effective exam

for acoustic neuroma, useful in other diagnosisfor acoustic neuroma, useful in other diagnosis

Dr. Peltier’s Dizzy EvaluationDr. Peltier’s Dizzy Evaluation ENGENG

• Patients unresponsive to conservative treatmentPatients unresponsive to conservative treatment• Severe symptoms and not suspicious of acute vestibular Severe symptoms and not suspicious of acute vestibular

infectioninfection• Diagnosis uncertain and chronic symptomsDiagnosis uncertain and chronic symptoms• Pre-op when vestibular ablation procedure consideredPre-op when vestibular ablation procedure considered• When documentation of vestibular function is necessaryWhen documentation of vestibular function is necessary• When referred from neurology for evaluationWhen referred from neurology for evaluation

MRIMRI• Any suspicion of central lesions by physicial, or objective Any suspicion of central lesions by physicial, or objective

testingtesting Posturography/Chair testing/VEMPPosturography/Chair testing/VEMP

• Not available at UTMBNot available at UTMB• Of questionable clinical utilityOf questionable clinical utility

ReferencesReferences Kroenke, Lucas, Rosenberg et al. Kroenke, Lucas, Rosenberg et al. Causes of persistent dizziness: a prospective Causes of persistent dizziness: a prospective

study of 100 patients in ambulatory care. study of 100 patients in ambulatory care. Ann Intern Med, 117Ann Intern Med, 117 (11), 898-905. (11), 898-905. Allum, H.J., & Shepard, N. T. (1999), An overview of the clinical use of dynamic Allum, H.J., & Shepard, N. T. (1999), An overview of the clinical use of dynamic

posturography in the differential diagnosis of balance disorders. J Vestib Res, 9, 223-posturography in the differential diagnosis of balance disorders. J Vestib Res, 9, 223-252252

Kaplan, Marais et. al. (2001), Does High-Frequency Pseudo-random Rotational Chair Kaplan, Marais et. al. (2001), Does High-Frequency Pseudo-random Rotational Chair Testing Increase the Diagnostic Yield of the ENG Caloric Test in Detecting Bilateral Testing Increase the Diagnostic Yield of the ENG Caloric Test in Detecting Bilateral Vestibular Loss in the Dizzy Patient? Laryngoscope, 111: 959-963Vestibular Loss in the Dizzy Patient? Laryngoscope, 111: 959-963

Hain, Timothy, Vestibular Evoked Myogenic Potential (VEMP) Testing Hain, Timothy, Vestibular Evoked Myogenic Potential (VEMP) Testing http://www.dizziness-and-balance.com/testing/vemp.htmlhttp://www.dizziness-and-balance.com/testing/vemp.html

Hajioff, D et. al. Is electronystagmography of diagnostic value in the elderly? Clinical Hajioff, D et. al. Is electronystagmography of diagnostic value in the elderly? Clinical Otolaryngology, 27(1) Feb. 2002 pp 27-31Otolaryngology, 27(1) Feb. 2002 pp 27-31

Desmond, Alan. Vestibular Function: Evaluation and Treatment. Thieme Medical Desmond, Alan. Vestibular Function: Evaluation and Treatment. Thieme Medical Publishers, INC New York, NY 2004. pp 65-111.Publishers, INC New York, NY 2004. pp 65-111.

Stockwell, Charles. Introduction to ENG. ICS Medical, Schaumburg, Illinois, 2001, Stockwell, Charles. Introduction to ENG. ICS Medical, Schaumburg, Illinois, 2001, multiple pages.multiple pages.

Stockwell, Charles. Catalog of ENG abnormalities. Stockwell, Charles. Catalog of ENG abnormalities. ICS Medical, Schaumburg, ICS Medical, Schaumburg, Illinois, 2001, multiple pages.Illinois, 2001, multiple pages.

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vertigo and the vestibular system

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