Vestibular: Postural Control Exam Flashcards by Tahlia Wasserman

What are the biomechanical factors that contribute to stability and orientation?

Degrees of freedom
Strength
Limits of stability

How well did you know this?

Not at all

Perfectly

What are the movt strategies that contribute to stability and orientation?

Reactive
Anticipatory
Voluntary

How well did you know this?

Not at all

Perfectly

What are the orientations in space the contribute to stability and orientation?

Perception
Gravity
Surfaces
Vision
Verticality

How well did you know this?

Not at all

Perfectly

What are the sensory strategies that contribute to stability and orientation?

Sensory integration
Sensory reweighting

How well did you know this?

Not at all

Perfectly

What are the controls of dynamics that contribute to stability and orientation?

Gait and proactive responses

How well did you know this?

Not at all

Perfectly

What are the cognitive processes that contribute to stability and orientation?

Attention and learning

How well did you know this?

Not at all

Perfectly

What test can we use to determine which type of balance problem a pt presents with?

The miniBEST test

How well did you know this?

Not at all

Perfectly

What is the go to test for balance and vestibular pts?

The miniBEST test

How well did you know this?

Not at all

Perfectly

What are the 6 specific domains of postural control?

Dynamic gait (including sensory and motor)
Sensory organization and weighting
COG position and voluntary control (limits of stability)
Postural responses (strategies, APAs, RPRs)
Dual tasking (cognitive interference)
MSK, cardio considerations

How well did you know this?

Not at all

Perfectly

What is the DGI?

A dynamic gait screen with 4 items to assess balance

How well did you know this?

Not at all

Perfectly

What are the 4 items on the DGI?

Horizontal head turns
Vertical head turns
Gait on level surfaces
Changes in gait speed

How well did you know this?

Not at all

Perfectly

What is the max score of the DGI?

How well did you know this?

Not at all

Perfectly

A score of less than 10/12 on the DGI indicates what?

Fall risk

How well did you know this?

Not at all

Perfectly

Is the pt allowed to use an AD with the FGA?

Yes

How well did you know this?

Not at all

Perfectly

What is the FGA?

A modification of the DGI with improved reliability and decreased ceiling effect

How well did you know this?

Not at all

Perfectly

What is the cutoff scores for the FGA?

Greater than or equal to 22/30 predicts falls in older adults

How well did you know this?

Not at all

Perfectly

What are the tests done with the computerized dynamic posturography?

Sensory organization test (SOT)
Motor control test (MCT)
Adaptation test (ADT)
Limits of stability (LOS)
COG position/control

How well did you know this?

Not at all

Perfectly

What is the SOT (sensory organization test)?

A 6 condition test with high specificity for what part of the system is contribution to imbalance

How well did you know this?

Not at all

Perfectly

What is condition one of the SOT?

EO
Firm surface

How well did you know this?

Not at all

Perfectly

When would we expect a pt to have issues with condition one of the SOT?

If they have a central lesion like a cerebellar issue
If they are making it up

How well did you know this?

Not at all

Perfectly

What is condition two of the SOT?

EC
Firm surface

How well did you know this?

Not at all

Perfectly

What is condition three of the SOT?

Firm surface
Moving environment with head in computer thingy creating unsteady vision

How well did you know this?

Not at all

Perfectly

What is condition four of the SOT?

Unstable surface
EO

How well did you know this?

Not at all

Perfectly

What is condition five of the SOT?

Unstable surface
EC

How well did you know this?

Not at all

Perfectly

What is condition six of the SOT?

Unstable surface Moving visual input in computer thingy to create unstable vision

What are the accurate systems in condition one of the SOT?

Vestibular Vision Somatosensory

What are the inaccurate systems in condition one of the SOT?

None

What are the accurate systems in condition two of the SOT?

Vestibular Somatosensory

What are the inaccurate systems in condition two of the SOT?

Vision

What systems are accurate in condition three of the SOT?

Vestibular Somatosensory

What systems are inaccurate in condition three of the SOT?

Vision

What systems are accurate in condition four of the SOT?

Vestibular Visual

What systems are inaccurate in condition four of the SOT?

Somatosensory

What systems are accurate in condition five of the SOT?

Vestibular

What systems are inaccurate in condition five of the SOT?

Somatosensory Vision

What systems are accurate in condition six of the SOT?

Vestibular

What systems are inaccurate in condition six of the SOT?

Vision Somatosensory

What is the difference between condition five and six of the SOT?

Condition five takes away vision and therefore unreliable Condition six makes vision unstable and therefore unreliable Both make vision unreliable to test the vestibular system but are treated differently

T/f: you have to the stress the system to make it work

True

You have to manipulate _____ input to change motor output

Sensory

T/f: decreased strength and ROM can decrease the sway envelope available and make balance worse

True

With a polyneuropathy, what are the two possible outcomes of putting the pt in condition two of the SOT (firm surface, EC)?

They could have a lot of sway bc they already have impaired somatosensation and now you are taking away their visual system, so they have to relay in their vestibular system OR they could have no sway bc they have adapted to their changed somatosensation

What should we document about sway?

The direction and timing of it

How can we determine a pts COG?

Using a posturographic measurement (big tech stuff) Using observation in the clinic

What are stability limits (limits of stability = LOS)?

The boundaries within which the body can maintain stability w/o changing the BOS

What mechanical factors limit normal COG position and LOS?

COG position and control BOS ROM strength

What internal factors limit normal COG position and LOS?

Perception

Other than mechanical and internal factors, what can limit normal COG position and LOS?

Accurate interpretation Pain Experience with anxiety or fear

What is the only way to evaluate postural strategies?

Careful observation in the clinic

What questions should we be considering about a pts postural response strategies?

Is the pt choosing the appropriate strategy for the surface situation Is the pt choosing the appropriate strategy for their stability and sway?

When an individual is unstable on an unstable or narrow surface, what strategy should be used?

Hip strategy

When an individual is stable and on a stable or broad surface, what strategy should be used?

Ankle strategy

If the individual is stable on a stable or broad surface and they are using a hip strategy, is this an appropriate strategy choice?

Nope, they should be using ankle strategies

If an individual is unstable on an unstable or narrow surface and they are using ankle strategies, if this appropriate for the situation?

No, they should be using hip strategies

When should the ankle strategy be used?

When the surface is firm When the sway/demand is little Slow sway

When should the hip strategies be used?

On unstable surfaces On narrow BOS When perturbations and sway are too much

How can we test dual tasking?

TUGc (not explaining this one bc I think we all got this one)

How can we measure postural response strategies?

The miniBEST test

What inertial measurement options we should quantify?

Postural control/balance Gait TUG

How can we quantify COG sway area, mean sway, sway acceleration, and sway “jerk”?

With wearable sensors

How can we quantify gait?

With gait velocity

What component impairments may be present with imbalances?

Biomechanical alignment and control Sensory system fxn, weighting, or integration Motor system fxn or movt strategies Cognitive or perceptual processes Interaction with other systems Integration into dynamic gait and fxn

What is electronystagmography (ENG)?

Use of electrodes placed to recorder and measure each eye muscle response

What is videonystagmography (VNG)?

Use of video/video infrared recording to observe, record, and measure eye muscle responses

What do ENG and VNG do?

Record eye movt in response to a stim delivered to each vestibular apparatus

What is caloric testing?

Using cold or warm water/air irrigated into the external auditory canal to induce nystagmus

What does a cold stim do in caloric testing?

Eyes move in horizontal nystagmus away from the side of the stim

What does a warm stim do in caloric testing?

Eyes move toward the side of the stim

What does absent or reduced reactive eye movt suggest in caloric testing?

It suggests a vestibular weakness of the horizontal SCC of the side being stimulated

If there is <25% difference bw the two ears with caloric testing, is this considered normal?

Yes

Increased responses of more than 25% in caloric testing usually signifies what?

Cerebellar disease

What is a normal response to caloric testing?

Equal intensity of the nystagmus response in both ears

If someone has a unilateral vestibular lesion, what would we see with caloric testing?

Decreased intensity of response in one ear

If someone has a bilateral vestibular lesion, what would we see on caloric testing?

No response or a very weak response in both ears

What is the stimulus in the rotational chair test?

Movt

What is the rotational chair test?

The pt is rotated in a chair in the dark with EO and ENG/VNG recording to stimulate both SCCs simultaneously in a pair where one is inhibited and the other excited

What is the rotational chair test used to measure?

The phase and gain (ratio) of head:eye movt

If the rotational chair test shows us decreased gain, what does this indicate?

Decreased vestibular sensitivity

Does a decreased gain in the rotational chair test usually indicate a unilateral or bilateral loss of vestibular fxn?

BL loss of vestibular fxn

If there is an abnormally large (increase) gain in the rotational chair test, what is this usually suggestive of?

Central dysfxn

What are the indications to use the rotational chair test?

Those in whom BL is suspected Pediatrics Those who can’t have or tolerate calorics Those in which aphyisologic is suspected

What is the vestibular autorotation test (VAT)?

A test for VOR gains and phases that is performed in room light The subject wears an accelerometer device on their head and is asked to focus on a stationary target and move their head at speeds greater than 2Hz and records the head and eye velocities

What is calculated by the VAT?

VOR gains (eye velocity amplitude/head velocity amplitude) and phases

What are VEMPs (vestibular evoked myogenic potentials)?

High intensity sounds that stimulate the vestibular system in the absence of head movt to provide a method for evaluating the otolithic organs separate from the SCC

What are the anatomical difference bw the utricle and saccule?

The utricle supplies the ipsi sup rectus and med rectus and the contralateral inf oblique and inf rectus via the sup vestibular nerve The saccule supplies the ipsi SCM muscle via the inf vestibular nerve

What are the fxnal differences bw the utricle and saccule?

The utricle is principally related to eye movt The saccule plays a major role in control of postural adjustments

What is the c-VEMP?

A series of clicks are used stimulate each ear to stimulate the saccule and inhibit the SCM on the same side The firing rate of the ipsi SCM is recorded using EMG (surface)

C-VEMP results are abnormal if….

One side is 2x larger than the others Low amplitude Absent

Abnormal results of the c-VEMP would indicate what otolithic organ?

Saccule

What is the o-VEMP?

Series of clicks used to stimulate each ear and stimulate the utricle that inhibits the contralateral inferior oblique Firing rate of the CL inf oblique is recoded using EMG (surface)

O-VEMP results are abnormal if…

Low in amplitude Absent

An abnormal result on the o-VEMP would indicate which otolithic organ?

The utricle