vestibular function test and its clinical examination
DESCRIPTION
vestibular function test and its clinical aplication Khushali Jogani The Sarvajanik College Of Physiotherapy, Rampura,Surat.TRANSCRIPT
VESTIBULAR FUNCTION TESTS AND ITS CLINICAL EXAMINATION
By: Khushali JoganiThe Sarvajanik College Of PhysiotherapyRampura,Surat
CONTENTS Introduction Anatomy Physiology Examination -History -scales -physical examination -Bedside testing and
manuevers -Laboratory testing References
INTRODUCTION Incidence of dizziness is 5.5 percent or
greater than 15 million people per year in united states
It increases as age increases Cawthorne and Cookey were the first one
to introduce exercises for dizziness Accurate diagnosis –minimization of
functional limitation-prevention of disability Mostly peripheral vestibular system is the
origin for patients signs and symptoms
Function of peripheral vestibular system -stabilization of visual images on the
fovea of retina during head movement to allow clear vision
-maintaining postural stability, especially during movement of head
-providing information used for spatial orientation
ANATOMY
PHYSIOLOGY Important for understanding the
signs and symptoms Principles are: -tonic firing rate -Vestibular reflexes -push-pull mechansim -inhibitory cut off -velocity storage system
1. Tonic firing rate resting firing rate is 70 to 100 spikes/s increase tonic firing rate means each
vestibular system detects head motion through excitation or inhibition
2. Vestibular reflexes vestibulospinal reflex ( it helps to
maination centre of gravity) vestibulocollic reflex(it helps to
maintain stability of head during movement of torso)
(VOR) vestibular ocular reflex( it helps in maintaining stability of an image on the fovea of retina during rapid head movements)
-pathway can be describes as three neuron arc
-horizontal head rotation about the vertical Z-axis (yaw)
- head extension or flexion about the horizontal Y-axis(pitch)
-lateral head tilt about the horizontal X-axis (roll)
VOR gain eye velocity/head velocity= -1 VOR phase described as zero phase shift VOR operates at head velocities as great
as 350 to 400 degree/s
3. Push pull mechanism
Faulty interpretation will lead to difficulty in gaze stabilization,postural stability and motion perception.
4. Inhibitory cut off5. Velocity storage system
EXAMINATIONHISTORY It can be divided into:- -elements that help with diagnosis -elements that lead to goals for
management including physical therapy
Elements that help with diagnosis are : -tempo -symptoms 1.vertigo 2.dysequilibrium 3.oscillopsia 4.light headedness 5.rocking or swaying 6.motion sickness 7. nausea and vomiting -circumstances -how it affects the patients life -medications
Elements that lead to goals for management, including physical therapy
-obtaining patient subjective complaints
-Using VAS (visual analogue scale ) to quantify the intensity of specific symptoms
-impact on functional activities using MULTIDIMENSIONAL DIZZINESS INVENTORY
-perceived disability
-fall history -where, when, what was thinking about - frequency of falls, any injuries
associated with that -confidence in balance using ABC
scale(Activities Specific Balance Confidence Scale)
-interference with daily activities-interference with recovery -PANAS scale( Positive Affect Negative
Affect Scale) if anxiety or depression is affecting
-Dizziness Handicap Inventory
-Motion Sensitivity Quotient
PHYSICAL EXAMINATION - what is nystagmus -observation for nystagmus tools used are 1. frenzel lenses 2.infrared camera
system 3.opthalmoscope 4.ganzfeld -skew eye deviation -problems with VOR -static imbalance -dynamic imbalance
BED SIDE TESTING
Head Thrust test Head Shaking Nystagmus
Test Clinical Vestibular Dynamic
Visual acuity Test
1.Head Thrust Test - used to examine semicircular canal
function - it can give indication for complete
loss of function in affected labyrinth -less sensitive in detecting
hypofunction in patients with incomplete loss of function
2.Head Shaking Induced Nystagmus Test
-useful in diagnosis of unilateral peripheral vestibular defect.
3. Dynamic Visual Acuity Test -it is measurement of visual acuity
during horizontal motion of head
Maneuver –Induced vertigo and eye movements
if mechanical problem (BPPV) dan certain manuevers should be performed that evoke nystagmus
1. positional testing( Hallpike-Dix test)
Hallpike –dix test
Roll Test for Horizontal Semicircular Canal
Visual tracking -smooth pursuit eye movement -cancellation of vestibulo ocular reflex -saccadic eye movement
Stance and gait examination
-Romberg test -Sharpened romberg (heel to toe tandem
stance) test -Fukuda’s Stepping test -Retropulsion test
LABORATORY TESTS Electronystagmography(ENG) or
Videonystagmography (VNG) Caloric Testing Rotatory Chair Testing Quantified Dynamic Visual Acuity Subjective Visual Vertical Computerised Dynamic Posturography Vestibular Evoked Myogenic Potential
Test(VEMP)
Electronystagmography
Caloric Testing
Rotatory Chair Testing
Quantified Dynamic Visual Acuity Test
Computerised Dynamic Posturography
REFERNCES Physical Rehabilitation By Susan B O’ Sullivan(fifth edition) Vestibular Rehabiliation By Susan J. Herdman( third edition) Rehabiliation Medicine :Principles
and Practice By Joel A Delisa and Bruce M.
Gans(third edition)
General vestibualr testing By T. Brandt, M.
Strupp/ClinicalNeurophysiology American physical therapy association By Barbara Susan Robinson
THANK YOU