Vestibular ExaminationVestibular Examination

ANATOMY & FUNCTIONANATOMY & FUNCTION

Carmen Casanova Abbott PT, PhDCarmen Casanova Abbott PT, PhD

Lecture ObjectivesLecture Objectives

► Discuss vestibular structure as it relates Discuss vestibular structure as it relates to vestibular function when examining a to vestibular function when examining a dizzy patient.dizzy patient.

► Discuss signs and symptoms associated Discuss signs and symptoms associated with vestibular disorderswith vestibular disorders

► Differentiate between peripheral and Differentiate between peripheral and central vestibular pathologycentral vestibular pathology

► Discuss components of a physical Discuss components of a physical therapy vestibular examination.therapy vestibular examination.

Vestibular System FunctionVestibular System Function

► Provides information concerning gravity, Provides information concerning gravity, rotation and accelerationrotation and acceleration

► Serves as a reference for the Serves as a reference for the somatosensory & visual systemssomatosensory & visual systems

► Contributes to integration of arousal, Contributes to integration of arousal, conscious awareness of the body via conscious awareness of the body via connections with vestibular cortex, connections with vestibular cortex, thalamus and reticular formationthalamus and reticular formation

► Allows for:Allows for: gaze & postural stabilitygaze & postural stability sense of orientationsense of orientation detection of linear & angular detection of linear & angular

accelerationacceleration

Vestibular AnatomyVestibular Anatomy► Peripheral sensory apparatusPeripheral sensory apparatus

detects & relays information about head angular & detects & relays information about head angular & linear velocity to central processing systemlinear velocity to central processing system

orients the head with respect to gravityorients the head with respect to gravity

► Central processing systemCentral processing system processes information in conjunction with other sensory processes information in conjunction with other sensory

inputs for position and movement of head in spaceinputs for position and movement of head in space

► Motor output systemMotor output system generates compensatory eye movements and generates compensatory eye movements and

compensatory body movements during head & postural compensatory body movements during head & postural adjustmentsadjustments

Peripheral ApparatusPeripheral Apparatus

►Membranous LabyrinthMembranous Labyrinth Semicircular canals (SSC)Semicircular canals (SSC) Otolith organsOtolith organs

Netter ‘97Netter ‘97

Semicircular CanalsSemicircular Canals

►Angular accelerationAngular acceleration►Ampulla contains sensory epitheliumAmpulla contains sensory epithelium

SSC Coplanar PairingSSC Coplanar Pairing► Spatial arrangement of the 6 SSC cause 3 Spatial arrangement of the 6 SSC cause 3

coplanar pairingscoplanar pairings R & L lateral, L anterior and R posterior; R & L lateral, L anterior and R posterior;

l posterior & R anterior; R & L horizontall posterior & R anterior; R & L horizontal► Allows for a Allows for a Push-PullPush-Pull arrangement of the arrangement of the

two sides two sides (e.g., as head turns right, right (e.g., as head turns right, right SSC willSSC will increase firing rate & the left SSC increase firing rate & the left SSC willwill decrease firing rate)decrease firing rate)

► AdvantagesAdvantages sensory redundancysensory redundancy common mode rejection/noisecommon mode rejection/noise assist in compensation for sensor assist in compensation for sensor

overloadoverload

Inhibitory CutoffInhibitory Cutoff

► Depolarization of the ipsilateral hair cells Depolarization of the ipsilateral hair cells occurs during angular head movementsoccurs during angular head movements

► Hyperpolarization of contralateral hair Hyperpolarization of contralateral hair cells occurs at the same timecells occurs at the same time

► Hair cells are only able to hyperpolarize Hair cells are only able to hyperpolarize to what they were at rest = cut off of to what they were at rest = cut off of inhibitory influences from the movement inhibitory influences from the movement going in the opposite direction even if going in the opposite direction even if the ipsilateral hair cells continue to spike the ipsilateral hair cells continue to spike higher firing rateshigher firing rates

Purves 2001Purves 2001

OtolithsOtoliths

►Utricle and sacculeUtricle and saccule►Otolith sensory structuresOtolith sensory structures

MaculaeMaculae Otolithic membraneOtolithic membrane OtoconiaOtoconia

►Movement of gel membrane & Movement of gel membrane & otoconia cause a shearing action otoconia cause a shearing action to occur over the hair cells to occur over the hair cells → → sensitivity of otolithssensitivity of otoliths

Otolith FunctionOtolith Function

►Respond to:Respond to: Linear head motion on accelerationLinear head motion on acceleration Static tiltStatic tilt Two organs respond to respective Two organs respond to respective

accelerations or tilts in their respective accelerations or tilts in their respective planesplanes

►Saccule has vertical orientation of maculaeSaccule has vertical orientation of maculae►Utricle has horizontal orientation of maculaeUtricle has horizontal orientation of maculae

Bear 1996Bear 1996

Purves 2001.

Hair CellsHair Cells

►2 types: kinocilium & stereocilia2 types: kinocilium & stereocilia►Sensory structures for the peripheral Sensory structures for the peripheral

end organs end organs (maculae and ampula)(maculae and ampula)►Hyperpolarized or depolarized Hyperpolarized or depolarized

depending upon the direction of depending upon the direction of deflection of the stereocilia deflection of the stereocilia (movement of stereocilia towards(movement of stereocilia towards the kinocilium causes depolarization the kinocilium causes depolarization of the hair cell)of the hair cell)

►Affect the firing rate of the primary Affect the firing rate of the primary vestibular afferents to the brainstemvestibular afferents to the brainstem

Bear 1996Bear 1996

Striola of the MaculaStriola of the Macula

►Striola serves as a structural Striola serves as a structural landmarklandmark

►Contains otoconia arranged in Contains otoconia arranged in narrow trenches, dividing each narrow trenches, dividing each otolithotolith

►Orientation of the hair cells change Orientation of the hair cells change over the course of the maculaover the course of the macula

►Allows otoliths to have Allows otoliths to have multidirectional sensitivitymultidirectional sensitivity

Purves 2001.

Principles of the Vestibular Principles of the Vestibular SystemSystem

►Tonic firing rateTonic firing rate►Vestibular Ocular ReflexVestibular Ocular Reflex►Push-pull mechanismPush-pull mechanism► Inhibitory cutoffInhibitory cutoff►Velocity storage systemVelocity storage system

Ascending PathwaysAscending Pathways

►Vestibular nerveVestibular nerve►Vestibular nucleiVestibular nuclei►CerebellumCerebellum►Oculomotor complexOculomotor complex

CN 3, 4, and 6CN 3, 4, and 6 Along with vestibulospinal reflexes Along with vestibulospinal reflexes

coordinate head and eye movementscoordinate head and eye movements

Relay CentersRelay Centers►ThalamusThalamus

Connection with vestibular cortex and Connection with vestibular cortex and reticular formation reticular formation → arousal and conscious → arousal and conscious awareness of body; discrimination between awareness of body; discrimination between self movement vs. that of the environmentself movement vs. that of the environment

►Vestibular CortexVestibular Cortex Junction of parietal and insular lobeJunction of parietal and insular lobe Target for afferents along with the Target for afferents along with the

cerebellumcerebellum►Both process vestibular information with Both process vestibular information with

somatosensory and visual inputsomatosensory and visual input

Netter 1997Netter 1997

Tonic Firing RateTonic Firing Rate

► Vestibular nerve and vestibular nuclei Vestibular nerve and vestibular nuclei have a normal resting firing rate have a normal resting firing rate (70-(70-100 cycles/sec)100 cycles/sec)

► Baseline firing rate present without Baseline firing rate present without head movementhead movement

► Tonic firing is equal in both sides; if not, Tonic firing is equal in both sides; if not, a sense of motion is felt e.g., vertigo, a sense of motion is felt e.g., vertigo, tilt, impulsion, spinningtilt, impulsion, spinning

► Excitation and inhibition of the Excitation and inhibition of the vestibular system can then occur from vestibular system can then occur from stimulation of the hair cellsstimulation of the hair cells

► Spontaneous recovery with lightSpontaneous recovery with light

Vestibular-Ocular Reflex Vestibular-Ocular Reflex (VOR)(VOR)

►Causes eyes to move in the opposite Causes eyes to move in the opposite direction to head movementdirection to head movement

►Speed of the eye movement equals Speed of the eye movement equals that of the head movementthat of the head movement

►Allows objects to remain in focus Allows objects to remain in focus during head movementsduring head movements

Compensatory Eye Compensatory Eye MovementsMovements

►VORVOR►Optokinetic reflexOptokinetic reflex►Smooth pursuit reflex, saccades, Smooth pursuit reflex, saccades,

vergencevergence►Neck reflexesNeck reflexes

combine to stabilize object on the same combine to stabilize object on the same area of the retina=visual stabilityarea of the retina=visual stability

Purves 2001.

Vestibular ProcessingVestibular ProcessingGainGain

►Keeps eye still in space while head is Keeps eye still in space while head is movingmoving

►Ratio of eye movement to head Ratio of eye movement to head movement movement (equals 1)(equals 1)

Vestibular ProcessingVestibular ProcessingVelocity Storage MechanismVelocity Storage Mechanism

► Perseveration of neural firing in the Perseveration of neural firing in the vestibular nerve by the brainstem after vestibular nerve by the brainstem after stimulation of SSC to increase time stimulation of SSC to increase time constant constant (10sec.)(10sec.) SSC respond by producing an SSC respond by producing an

exponentially decaying change in neural exponentially decaying change in neural firing to sustained head movementfiring to sustained head movement

► Otolith & somatosensory input also drive Otolith & somatosensory input also drive mechanismmechanism

VOR DysfunctionVOR Dysfunction

►Direction of gaze will shift with the Direction of gaze will shift with the head movementhead movement

►Cause degradation of the visual imageCause degradation of the visual image► In severe cases, visual world will move In severe cases, visual world will move

with each head movementwith each head movement

OscillopsiaOscillopsia

►Visual illusion of oscillating Visual illusion of oscillating movement of stationary objectsmovement of stationary objects

►Can arise with lesions of peripheral Can arise with lesions of peripheral or central vestibular systemsor central vestibular systems

► Indicative of diminished VOR gainIndicative of diminished VOR gain motion of images on foveamotion of images on fovea diminished visual acuitydiminished visual acuity

CerebellumCerebellum

►Monitors vestibular performanceMonitors vestibular performance►Readjusts central vestibular Readjusts central vestibular

processing of static & dynamic processing of static & dynamic postural activitypostural activity

►Modulates VORModulates VOR►Provides inhibitory drive of VOR Provides inhibitory drive of VOR

(allows(allows for VORfor VORcc))

Descending PathwaysDescending Pathways

► Provide motor output from the Provide motor output from the vestibular system to:vestibular system to: Extraocular muscles Extraocular muscles (part of VOR)(part of VOR) Spinal cord & skeletal muscles Spinal cord & skeletal muscles

(generate(generate antigravity postural activity antigravity postural activity to cervical, trunk & lower extremity to cervical, trunk & lower extremity muscles)muscles)

► Response to changing head position Response to changing head position with respect to gravity with respect to gravity (righting,(righting, equilibrium responses)equilibrium responses)

Vestibulospinal Reflex (VSR)Vestibulospinal Reflex (VSR)

►Generates compensatory body Generates compensatory body movement to maintain head and movement to maintain head and postural stability, thereby preventing postural stability, thereby preventing fallsfalls

Netter 1997Netter 1997

Vestibular DysfunctionVestibular Dysfunction

DemographicsDemographics

►Vestibular disorders manifested by Vestibular disorders manifested by vertigo are a significant health vertigo are a significant health problem, secondary only to low back problem, secondary only to low back painpain

►NIH study estimates that 40% of the NIH study estimates that 40% of the population over the age of 40 will population over the age of 40 will experience a dizziness disorder during experience a dizziness disorder during their lifetimetheir lifetime

Fall DemographicsFall Demographics

►Falls will be experienced in Falls will be experienced in community dwelling individuals:community dwelling individuals: 28-35 % over age 6528-35 % over age 65 42-49% over age 7542-49% over age 75

► Greater than 60% will have bilateral Greater than 60% will have bilateral vestibular lesion (BVL) in the <65 or vestibular lesion (BVL) in the <65 or >75 years of age>75 years of age

Fall Risk FactorsFall Risk Factors

≥ 4 risk factors, 78% chance of falling in an older ≥ 4 risk factors, 78% chance of falling in an older adultadult

► SedativesSedatives► Cognitive Cognitive

impairmentimpairment► Palmomental reflexPalmomental reflex► LE disabilityLE disability► Foot problemsFoot problems► Balance Balance

abnormalitiesabnormalities

► DizzinessDizziness► ↑ ↑ dependence on dependence on

visual cuesvisual cues► Fear of fallingFear of falling► Orthostatic Orthostatic

hypotensionhypotension

(Tideiksaar R 1998)(Tideiksaar R 1998)

Other Fall Risk Factors?Other Fall Risk Factors?

Aging ChangesAging Changes

►Progressive changes begin at age 40Progressive changes begin at age 40 Decreased number of hair cellsDecreased number of hair cells Decreased vestibular nerve fibersDecreased vestibular nerve fibers

►Lead to dizziness and vertigoLead to dizziness and vertigo►Harder to deal with competing visual Harder to deal with competing visual

and somatosensory inputand somatosensory input

Fear of Falling (FOF)Fear of Falling (FOF)

► FOF affects willingness to participate in physical FOF affects willingness to participate in physical activity & exerciseactivity & exercise

► FOF occurs in an average of 30% of older adults FOF occurs in an average of 30% of older adults who have not fallenwho have not fallen

► FOF increases to an average of 60% of older FOF increases to an average of 60% of older adults who have fallenadults who have fallen

► FOF is higher among womenFOF is higher among women► Prevalence of FOF is underestimatedPrevalence of FOF is underestimated► Greater FOF associated with lower quality of life Greater FOF associated with lower quality of life

in mental health, social & leisure pursuitsin mental health, social & leisure pursuits

(Legters, 2002)(Legters, 2002)

Falls Related Self-efficacyFalls Related Self-efficacy

► Falls Efficacy Scales (FES)Falls Efficacy Scales (FES) better for frailbetter for frail indoor activitiesindoor activities

► Activities-Specific Balance Confidence Scale Activities-Specific Balance Confidence Scale (ABC)(ABC) higher functioninghigher functioning indoor & outdoor activitiesindoor & outdoor activities > discrimination between fearful & > discrimination between fearful &

nonfearfulnonfearful (Legters, 2002)(Legters, 2002)

Vestibular PathophysiologyVestibular Pathophysiology

► Disorders of tone & or gain Disorders of tone & or gain (vertigo /(vertigo / movement- induced vertigo)movement- induced vertigo)

► Vestibular nerve / nuclei give abnormal Vestibular nerve / nuclei give abnormal sensory informationsensory information

► Tone automatically recovers in a few days; Tone automatically recovers in a few days; does not need visual inputdoes not need visual input

► Compensation for reduced gain depends on Compensation for reduced gain depends on visual images; takes month to years to visual images; takes month to years to complete; high speeds & accelerations may complete; high speeds & accelerations may never be completenever be complete

► Nystagmus usually transient sign of Nystagmus usually transient sign of vestibular lesion; movement-induced vestibular lesion; movement-induced symptoms can be chronicsymptoms can be chronic

Dizzy Patient Presentation: unexplained Dizzy Patient Presentation: unexplained or new onset of symptomsor new onset of symptoms

► Medical referral is indicatedMedical referral is indicated constant vertigoconstant vertigo lateralpulsionlateralpulsion facial asymmetryfacial asymmetry speech & or swallowing difficultiesspeech & or swallowing difficulties oculomotor dysfunction oculomotor dysfunction vertical nystagmusvertical nystagmus severe headachessevere headaches recurrent fallsrecurrent falls unilateral hearing loss, tinnitus, fullness, ear painunilateral hearing loss, tinnitus, fullness, ear pain

VertigoVertigo

►An asymmetrical firing of the two An asymmetrical firing of the two vestibular systemsvestibular systems

►Gives an illusion of spinning, Gives an illusion of spinning, movementmovement

► Indicative of any one or combination Indicative of any one or combination of causes of causes (acute UVH, BPPV, (acute UVH, BPPV, brainstem lesion, vascular brainstem lesion, vascular hypotension…)hypotension…)

Differentiation Between Peripheral Differentiation Between Peripheral & Central Causes of Vertigo& Central Causes of Vertigo

PeripheralPeripheral CentralCentral

NauseaNausea severesevere moderate moderate

ImbalanceImbalance mildmild severe severe

Hearing LossHearing Loss commoncommon rare rare

OscillopsiaOscillopsia mildmild severe severe

Neurologic SymptomsNeurologic Symptoms rarerare common common

CompensationCompensation rapidrapid slow slow

((Furman JM, Whitney SL. 2000)Furman JM, Whitney SL. 2000)

Peripheral Vestibular Peripheral Vestibular DisordersDisorders

►Vestibular NeuronitisVestibular Neuronitis►LabyrinthitisLabyrinthitis►Meniere’s Meniere’s ►Acoustic NeuromaAcoustic Neuroma►FistulaFistula►Benign Paroxysmal Positional Vertigo Benign Paroxysmal Positional Vertigo

(BPPV)(BPPV)

Central Vestibular DisordersCentral Vestibular Disorders

►VascularVascular Wallenberg’s SyndromeWallenberg’s Syndrome Head InjuryHead Injury Cerebellar InfarctCerebellar Infarct

►Postconcussive SyndromePostconcussive Syndrome►Demyelinating DiseaseDemyelinating Disease►CongenitalCongenital

Degenerative Cerebellar Degenerative Cerebellar DiseaseDisease

►Signs & symptomsSigns & symptoms abnormal ocular pursuitabnormal ocular pursuit gradual declinegradual decline irregular saccadesirregular saccades gaze end point nystagmusgaze end point nystagmus ataxiaataxia

Objective of Clinical ExamObjective of Clinical Exam► Establish location & severity of lesion Establish location & severity of lesion (central or(central or

peripheral)peripheral)► Typical examinationTypical examination

- history - history (hearing status)(hearing status)- cranial nerves- cranial nerves- vestibular- vestibular

spontaneous nystagmus spontaneous nystagmus (imbalance in tone)(imbalance in tone)postural instability postural instability (abnormal tone & gain; (abnormal tone & gain;

proprioceptive loss)proprioceptive loss)VOR gain VOR gain (maintained fixation, dynamic visual acuity)(maintained fixation, dynamic visual acuity)head shaking head shaking (compensated UVL; not necessarily (compensated UVL; not necessarily

PVL)PVL)caloricscaloricspressure sensitivity pressure sensitivity (fistula)(fistula)positional nystagmus positional nystagmus (Hallpike-Dix test)(Hallpike-Dix test)hyperventilation hyperventilation (anxiety; acoustic neuroma)(anxiety; acoustic neuroma)

NystagmusNystagmus► Rapid alternating movement of eyes in Rapid alternating movement of eyes in

response to continued rotation of the response to continued rotation of the bodybody

► Primary diagnostic indicator in identifying Primary diagnostic indicator in identifying vestibular lesionsvestibular lesions

► Physiologic nystagmusPhysiologic nystagmus vestibular, visual, extreme lateral gazevestibular, visual, extreme lateral gaze

► Pathologic nystagmusPathologic nystagmus spontaneous, positional, gaze evokedspontaneous, positional, gaze evoked

► Labeled by the direction of the fast Labeled by the direction of the fast componentcomponent

► Central vs. peripheral cause Central vs. peripheral cause differentiated by duration differentiated by duration

Vestibular Function TestsVestibular Function Tests

►Caloric testCaloric test►Rotary Chair testRotary Chair test►PosturographyPosturography

Results of Vestibular Function Results of Vestibular Function TestsTests

►Presence of complete vs. incomplete Presence of complete vs. incomplete lossloss

►Presence of peripheral vs. central Presence of peripheral vs. central dysfunctiondysfunction

►Direct patient managementDirect patient management►Help in outcome predictionHelp in outcome prediction

Dizziness Handicap InventoryDizziness Handicap Inventory►Three subscalesThree subscales

functionfunction emotionemotion physical aspectsphysical aspects

►ScoringScoring YesYes 4 pts.4 pts. Sometimes 2 pts.Sometimes 2 pts. No 0 pts.No 0 pts.

►Excellent test-retest reliabilityExcellent test-retest reliability

Hallpike-Dix ManeuverHallpike-Dix Maneuver

►Gold standard used to check for the Gold standard used to check for the presence of benign paroxysmal presence of benign paroxysmal positional vertigo (BPPV)positional vertigo (BPPV)

►Nystagmus induced by this test is an Nystagmus induced by this test is an objective measurement from which we objective measurement from which we can determine SSC dysfunction and can determine SSC dysfunction and assess a response to treatmentassess a response to treatment

Benign Paroxysmal Positional Benign Paroxysmal Positional Vertigo (BPPV)Vertigo (BPPV)

►Signs & symptomsSigns & symptoms sudden, severe attacks of vertigo sudden, severe attacks of vertigo

precipitated by certain head positions & precipitated by certain head positions & movementsmovements

►e.g., rolling over, neck extension, bending e.g., rolling over, neck extension, bending forwardforward

lightheadedness; nausealightheadedness; nausea anxietyanxiety avoids movementavoids movement direction & duration of nystagmus direction & duration of nystagmus

differentiates between BPPV & a central differentiates between BPPV & a central vestibular lesion (CVL)vestibular lesion (CVL)

Benign Paroxysmal Positional Benign Paroxysmal Positional Vertigo (BPPV)Vertigo (BPPV)

► 5 criteria crucial in diagnosis (Hallpike-Dix 5 criteria crucial in diagnosis (Hallpike-Dix Test):Test): torsional/linear-rotary nystagmus; reproduced by torsional/linear-rotary nystagmus; reproduced by

provocative positioning with affected ear downprovocative positioning with affected ear down nystagmus of 1-5 sec. latency nystagmus of 1-5 sec. latency nystagmus of brief duration (5-30 sec.)nystagmus of brief duration (5-30 sec.) reversal of nystagmus direction on returning to reversal of nystagmus direction on returning to

upright positionupright position response diminishes with repetition of maneuver response diminishes with repetition of maneuver

(fatigability)(fatigability)((Massoud ’96)Massoud ’96)

BPPVBPPVCupulolithiasisCupulolithiasis

►Debris, probably fragments of otoconia Debris, probably fragments of otoconia from the utricle, adhere to the cupulafrom the utricle, adhere to the cupula

►TreatmentTreatment Brandt-Daroff habituation exercisesBrandt-Daroff habituation exercises Semont, liberatory maneuverSemont, liberatory maneuver

BPPVBPPVCanalithiasisCanalithiasis

►Debris floating freely in the Debris floating freely in the endolymph in the long arm of the endolymph in the long arm of the posterior SSCposterior SSC

►TreatmentTreatment Canalith repositioning maneuver (Canalith repositioning maneuver (Epley)Epley) 84-90% remission rate84-90% remission rate Sleep upright one night only Sleep upright one night only (more severe(more severe

cases)cases)

Problems Experienced with Problems Experienced with Vestibular LossVestibular Loss

►Balance & gait deficitsBalance & gait deficits►Head movement-induced dizzinessHead movement-induced dizziness►Head movement-induced visual Head movement-induced visual

blurring blurring (oscillopsia)(oscillopsia)►LE dressing difficultyLE dressing difficulty►Driving deficitsDriving deficits►Disability related to work, social & Disability related to work, social &

leisure activitiesleisure activities

Systems Approach to Systems Approach to ExaminationExamination

►Examination of balance & mobility Examination of balance & mobility using a variety of tests & using a variety of tests & measurements to document functional measurements to document functional abilities, determine underlying abilities, determine underlying sensory, motor, & cognitive sensory, motor, & cognitive impairments contributing to functional impairments contributing to functional disabilitiesdisabilities

BalanceBalance

►Can be viewed as a motor skill that Can be viewed as a motor skill that emerges from the interaction of emerges from the interaction of multiple systemsmultiple systems

►These systems are organized to meet These systems are organized to meet functional task goals & are functional task goals & are constrained by the type of constrained by the type of environmentenvironment

►Balance, like any skill, can improve Balance, like any skill, can improve with practicewith practice

Balance ComponentsBalance Components

►SteadinessSteadiness►SymmetrySymmetry►Dynamic stabilityDynamic stability

Balance Training: Postural Balance Training: Postural BiofeedbackBiofeedback

►Postural symmetry & dynamic Postural symmetry & dynamic stability have been consistently stability have been consistently improved by training using force improved by training using force platform systemsplatform systems

Clinical Test of Sensory Clinical Test of Sensory Interaction In Balance Interaction In Balance

(CTSIB)(CTSIB)►Assesses pattern of sensory Assesses pattern of sensory

dependence for balance from timed dependence for balance from timed stance tests during distortion of stance tests during distortion of sensory environmentsensory environment

Berg Balance ScaleBerg Balance Scale

►Performance -orientated balance Performance -orientated balance assessmentassessment

► Interpretation:Interpretation: > 45/56 score highly specific (96%) for > 45/56 score highly specific (96%) for

nonfallersnonfallers subjects who fell most frequently were subjects who fell most frequently were

those closer to cut offthose closer to cut off

►Correlates with other balance testsCorrelates with other balance tests

Functional Gait Assessment Functional Gait Assessment (FGA)(FGA)

►Assesses postural stability during walkingAssesses postural stability during walking►Modified version of the Dynamic Gait Modified version of the Dynamic Gait

IndexIndex►Added 3 new tasks to increase challenge Added 3 new tasks to increase challenge

and sensitivity of the test to minor and sensitivity of the test to minor changes in gaitchanges in gait

►Stronger vestibular components Stronger vestibular components (head (head turns, narrow BOS, ambulating turns, narrow BOS, ambulating backwards and with eyes closed)backwards and with eyes closed)

General Therapeutic General Therapeutic Intervention ObjectivesIntervention Objectives

►Changing impairmentsChanging impairments► Improving functional performanceImproving functional performance► Improving capacity to adapt Improving capacity to adapt

performance to changing task & performance to changing task & environmental demandsenvironmental demands

Mechanism of Recovery:Mechanism of Recovery:CompensationCompensation

► Results from changes in CNSResults from changes in CNS rebalancing of tonic activity within vestibular rebalancing of tonic activity within vestibular

nuclei nuclei (spontaneous recovery)(spontaneous recovery) recovery of VOR recovery of VOR (vestibular adaptation)(vestibular adaptation) habituation habituation (progressive decline in response to (progressive decline in response to

same stimulus)same stimulus) alternative strategies/substitution; in complete alternative strategies/substitution; in complete

loss of vestibular functionloss of vestibular function

► Enhanced by active movements & processing Enhanced by active movements & processing of visual, vestibular, & somatosensory stimuliof visual, vestibular, & somatosensory stimuli

Result of Early InterventionResult of Early Intervention

►Gain returns quickerGain returns quicker► Increased functionIncreased function►Decreased gait ataxiaDecreased gait ataxia►Decreased perception of disequilibriumDecreased perception of disequilibrium

(Herdman 2000)(Herdman 2000)

Vestibular Exercise ProgramVestibular Exercise ProgramObjectivesObjectives

► Complement CNS natural compensationComplement CNS natural compensation diminish dizziness & vertigodiminish dizziness & vertigo enhance gaze stabilizationenhance gaze stabilization enhance postural stability in static & enhance postural stability in static &

dynamic situationsdynamic situations► Increase overall functional activitiesIncrease overall functional activities► Patient educationPatient education

nature of pathologynature of pathology episodic nature, prognosisepisodic nature, prognosis control of exacerbationscontrol of exacerbations

Vestibular Program Vestibular Program ComponentsComponents

►Gaze stabilization exercises to retrain Gaze stabilization exercises to retrain VOR functionVOR function

►Balance retraining to retrain VSR Balance retraining to retrain VSR functionfunction

►Conditioning exercises to increase Conditioning exercises to increase fitness levelfitness level

►Habituation or canal repositioning Habituation or canal repositioning maneuvers as indicatedmaneuvers as indicated

e.g., Unilateral Vestibular e.g., Unilateral Vestibular Lesion: Exercise GuidelinesLesion: Exercise Guidelines

► Adaptation is best stimulated by Adaptation is best stimulated by producing an error signal; work at limit producing an error signal; work at limit of abilitiesof abilities

► Incorporation of head movements & Incorporation of head movements & visual inputvisual input

► Provide context specific stimulation to Provide context specific stimulation to promote adaptationpromote adaptation

► Adaptation is positively affected by Adaptation is positively affected by voluntary muscle controlvoluntary muscle control

► (Herdman 2000)(Herdman 2000)

Vestibular Function Recovery Vestibular Function Recovery RatesRates

►UVL: 6-8 weeksUVL: 6-8 weeks►BPPV: remission in 1/few treatmentsBPPV: remission in 1/few treatments►BVL: 6 months - 2 yearsBVL: 6 months - 2 years►CNS Lesion: 6 months - 2 yearsCNS Lesion: 6 months - 2 years

Physical Therapy Intervention: Physical Therapy Intervention: PrescriptionPrescription

► Individualized vestibular Individualized vestibular rehabilitation program:rehabilitation program: Outpatient, 1-2 times / week Outpatient, 1-2 times / week (4-6 weeks)(4-6 weeks) HEP, 5 minutes, 3x / dayHEP, 5 minutes, 3x / day Walking program Walking program (health & fitness (health & fitness

prescription)prescription)

►Compliance to daily program Compliance to daily program essential to successessential to success

►Exercise graduated for possible Exercise graduated for possible increase of symptoms during the increase of symptoms during the first weekfirst week