Download - 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
Electronystagmography (ENG)Electronystagmography (ENG)
Electronystagmography (ENG)Electronystagmography (ENG)
Electronystagmography (ENG)Electronystagmography (ENG)
Oculomotor testsOculomotor tests Positional testsPositional tests Caloric tests Caloric tests
Electronystagmography (ENG)Electronystagmography (ENG)
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
Saccadic TrackingSaccadic Tracking
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
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
Rotational Chair TestingRotational Chair Testing
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
PosturographyPosturography
PosturographyPosturography
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
Vestibular Evoked Myogenic Vestibular Evoked Myogenic Potentials (VEMP’s)Potentials (VEMP’s)
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
Vestibular Evoked Myogenic Vestibular Evoked Myogenic Potentials (VEMP’s)Potentials (VEMP’s)
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.