Vestibular 1 Flashcards
(330 cards)
1
Q
Causes of Vestibular Disorders
A
- Head Trauma
- Otitis Media
- Bacterial Labyrinthitis
- Ototoxic Medications
- Ischemia
- Vestibualr Schwanomma
- Endolymphm Hydrops (menieres)
Know 5 from above
2
Q
What is the leading cause of TBI’s & Fractures
A
Falls are the leading cause of brain injury (TBI’s) and fractures
3
Q
what is true vertigo?
A
True vertigo is when the room/enviorment is spinning or you/self is spinning
4
Q
What is the likely point of origin for true vertigo
A
True vertigo is likely peripheral (inner ear)
5
Q
Maintaining balance is dependent on what?
A
Balance is dependent on sensory information gathered from visual, somatosensory & Vestibular receptors in the body
6
Q
What the stages of the balance process tranmission?
A
- Sensory information from the visual, somatosesnory & vestibualr is picked up by their receptors
- It is then sent to the brainstem
- Brainstem integrates info
- sent to the Cortex for perception & Processing.
7
Q
What streamlines the balance processs?
A
The Cerebellum & Cerebral Cortex streamline the process by coordinating incoming impulses & adding info from thinking & memory
8
Q
Balance
__________ information is constantly changing as a fucntion of movement.
A
Visual & Somatosensory
9
Q
Balance
_____ is always the same
A
Vestibular (gravity) is always the same.
10
Q
Define Peripheral
A
Inner ear (labyrinth & 8th nerve up to the point it enters the braistem
11
Q
Define Central
A
CNS
(brainstem to cortex)
12
Q
Vision Denied
A
Eyes closed/covered
Patient is without visual target
13
Q
Vision Allowed
A
Eyes open/uncovered
Patient is with visual target, able to fixate
14
Q
Name the two sensory structures within the Peripheral Vestibular system
A
Semicircular canal - Cristae Ampullaris
Otolithic Organs (utricle & saccule) - Maculae
15
Q
SCC detect ____ _____ of the head/body
A
SCC detect angular acceleration of the head/body
16
Q
what does it mean when i say SCC Function in a complimentary ‘push - pull’ fashion with opposite ear
A
- Two ears work together in balance detection
- When one ear is excitatory teh opposite is inhibitory
- turn head right - right SCC = excited. at the same time left SCC = inhibited
17
Q
what are the Otolithic Organs
A
Utricle & Saccule
18
Q
Detects linear acceleration in the horizontal plane & tilt
moving forward in a car or side to side
A
Utricle
19
Q
Detects linear acceleration in the vertical plane
going up or down in an elevator
A
Saccule
Plays a role in sensing gravity and head orientation.
20
Q
Name the parts of the cochlea
A
- outer wall = Bony labyrinth
- Membranous labyrinth - suspended in endolymph
- Utricle & Saccule - otoconia
- Vestibaulr hair cells
- SCC (3)
- Vestibular hair cells
- Cristae in ampulla
- on top of cristae = cupula.
21
Q
The outer wall of the labyrinth is called what?
A
The bony labyrinth and is filled with perilymph
22
Q
Bony Labyrinth filled with what?
A
Perilymph
23
Q
Inside the bony labyrinth is what?
A
Inside the bony labyrinth & suspended in perilymph is membranous labyrinth
24
Q
The membranous labyrinth is filled with what?
A
Membranous labyrinth filled with endolymph
25
Membranous labyrinth is suspened in what?
Membranous Labyrinth suspended in perilymph
26
Name the 5 sensory organs housed within the membranous labyrinth
- Utricle macula
- Saccule Macula
- Three Cristae Ampullaris
27
Plays a large role in postural control and primarily senses changes in orientation with respect to gravity
The **utricle** plays a large role in postural control and primarily senses changes in orientation with respect to gravity.
28
important for maintaining balance and keeping the body in the correct posture
The **utricle** is important for maintaining balance and keeping the body in the correct posture
29
What is Saccules function
- It is connected though the vestibular aqueduct & no open communcation with utricle & SCC
- Detects linear acceleration in the vertical plane
30
what consists of a layer of calcium carbonate crystals aka otoconia
Macula
31
Anatomy of the utricle & saccule
- Macula (layer of otoconia)
- Otoconia
- Below otoconia- gelatinous membrane
- Vestibaular hair cells - stereocillia extend into the GM
- Otoconia shift due to head movement
32
Posterior canal shares a plane with ____
Posterior canal shares a plane with the contralateral anterior canal
33
Anterior canal is paired with ______
Anterior canal is paired with posterior canal of opposite ear
34
Horizontal canal shares a plane with____
Horizontal canals share plane
35
Left Anterior with ______
Left Anterior with right posterior
36
left posterior with ___
Left posterior with right anterior
37
left horizontal with ___
left horizontal with right horizontal.
38
What are the sensory cells in the SCC
cristae or cristae ampullaris
39
The sensory cell in the Otolithic Organs
maculae
40
The vestibular hair cells in the inner ear are stimulated when
The vestibular hair cells in the inner ear are stimulated when they bend in response to motion or changes in head position
41
Movement that causes the stereocilia to flow towards the kinocilium =
Movement that causes the stereocilia to flow towards the kinocilium = **depolarization & increases in electrical charge**
42
When the stereocilia bend toward the kinocilium, the ion channels
When the stereocilia bend toward the kinocilium, the ion channels **open, allowing positively charged ions (such as potassium) to flow into the cell. depolarizing the hair cells increasing activity**
43
Movement that causes stereocilia to flow away from the kinocilium
Movement that causes stereocilia to flow away from the kinocilium = **hyperpolarization & decreases in electrical potential**
44
The stereocilia bend away from the kinocilium, the ion channels
if the stereocilia bend away from the kinocilium, the ion channels **close, hyperpolarization occurs decreasing the electrical activity of the hair cell.**
45
# What canal
Endolymph movement towards the ampulla = Excitation
Endolymph movement away from the ampulla = Inhibitory
Horizontal
46
# Name canal
Endolymph movement towards the ampulla = Inhibitory
Endolymph movement away from the ampulla = Excitation
Anterior or Posterior
47
____ Endolymph flow towards ampulla = Excitatory
______ Endolymph flow towards ampulla = Inhibitory
**Horizontal** Canal Endolymph flow towards ampulla = Excitatory
**Anterior & Posterior** Endolymph flow towards ampulla = Inhibitory
48
# Name canal
Endolymph movement towards the ampulla = Inhibitory
Endolymph movement away from the ampulla = Excitation
Anterior or Posterior
49
Vestibular Hair cells are oriented towards the striola in the ____
Vestibular Hair cells are oriented towards the striola in the utricle
50
Vestibular Hair cells are oriented away from the striola in the ____
Vestibular Hair cells are oriented away from the striola in the saccule
51
# CN 8 Divisions
Utricle, anterior part of saccule, horizontal & anterior canals.
Superior Division
52
# CN 8 Divisions
Posterior part of saccule, and posterior canal.
Inferior Division
53
# CN 8 Divisions
Superior Division
Utricle, anterior part of saccule, horizontal & anterior canals.
54
# CN 8 Divisions
Inferior Division
Posterior part of saccule, and posterior canal.
55
Superior Rectus CN
Cranial nerve 3, Elevates - raises eyes
| LR6SO4 all the rest are 3
56
Inferior Rectus CN
Cranial Nerve 3, Depression - pulls down
57
Medial Rectus, CN
Cranial Nerve 3 Adducts - pulls towards nose
58
Lateral rectus CN
Cranial Nerve 6, Abducts - moves the eye away from the midline
59
Superior Oblique, CN
Cranial Nerve 4
- Intorsion (inward rotation) → The top of the eye rotates toward the nose.
- Down & Away
60
Inferior Oblique, CN
Cranial Nerve 3
- Extorsion (outward rotation) → The top of the eye rotates away from the nose.
- Up & Away
61
Name the eye Muscules for cranial nerve 3
* Medial Rectus
* Inferior Rectus
* Superior Rectus
* Inferior Oblique
62
Name the eye muscles for cranial nerve 6
Lateral Rectus
- moves eye away from midline
63
Name the eye muscle for cranial nerve 4
Superior Oblique
- intorsion; top of eye rotates towards nose
64
Name the 3 important functions of the Vestibuar system
1. To porvide subjective senssation of movement and/or displacement in 3 dimentional space
2. To Maintain upright body posture (balance)
3. To stabilize the eyes during head/body movement
65
Name the three Vestibular Reflexes
* VOR (vestibulo-ocular reflex) = Stabilizes Vision (coordinating eye w/head movement)
* VCR (Vestibulo-Collic Reflex) = Head stabilization (via neck muscles)
* VSR (Vestibulo-Spinal Reflex) = Whole-body balance (via spinal/postural muscles)
66
Name the Vestibular Reflexes
VOR - Reflexive eye movement to enable clear vision during head movement.
VCR - a reflex that helps stabilize the head to keep the head in horizontal gaze position.
VSR -compensatory body movements to maintain head and postural stability in upper and lower limbs;
67
What does VOR stand for?
Vestibulo-ocular Reflex
VOR
68
What does VCR stand for
Vestibulo-collic Reflex
VCR
69
What does VSR Stand for?
Vestibulospinal Reflex
70
The VOR generates reflexive eye movements that are ____ to but _____ of ______
THe VOR generate reflexive eye movements that are **equal** to but **opposite** of **head movement**
71
# True or false
The CNS will cause eyes to rapidly move back to center to establish new focal point via saccade
True
VOR - system
72
What tests are used to asses VOR?
VNG (caloric), Rotational Tests (rotary chair), head thrust or vHIT
73
What tests are used to asses VSR?
SOT (CDP) or other postural stability exam
74
What tests are used to asses VCR?
VEMP
75
How are the hair cells oriented in the urticle?
Hair cells are oriented **toward the striola** in the urticle
76
How are the hair cells oriented in the Saccule?
Hair cells are oriented **away from the striola** in the saccule
| sAccule - A, Away
77
Stimulation towards kinocilium =
Stimulation towards kinocilium = cell depolarization & increased nerve activity
78
Define Nystgmus
Involuntary rhythmic oscillation of the eye
- many different types
79
Direction of nystagmus is determined by what
Direection of nystgmus is determined by the fast phase
| RB,LF, UB or DB
80
How do you determine the strength?
The strength is measured by the slow phase, slope
81
Slow phase is generated by what
The slow phase is generated by the **vestibular system**
- tells you how the vestibular system is operating
82
Fast phase is generated by what
Fast phase is genered by the **central system**
- does not tell us about teh vestibualr system
83
The slow phase is driven by
The slow phase is driven by the **ears (peripheral vestibular)**
84
The fast phase is driven by
The fast phase is driven by the **CNS (Central)**
85
Nystgmus beats away from what
nystgmus beats away from the affected ear.
86
What is an ENG/VNG
- primarly 2-D recordings horizontal (H) & Vertical (V) movements
- We can recoed vision denied & vision allowed
87
# Horizontal
Name the type of nystgmus
Left beating Nystgmus
* For horizontal lay your had on slow phase
- left hand for left beating
88
# Horizontal
Name the type of nystgmus
Right beating nystgmus
* For horizontal lay your had on slow phase
- right hand for right beating
89
# Vertical
Name the type of nystgmus
Down beating nystgamus
- For vertical left is down & right is up
- Up tight, down low
90
# Vertical
Name the type of nystgmus
Up beating nystgmus
Down beating nystgamus
- For vertical right is up & left is down
- Up right, down low
91
What is ENG/VNGs good at capturing?
LB,RB,UB,DB nystgamus - good
- Not torsional, 2-d systems do not capture well but video recodign to infer from
92
What does torsional nysytagmus look like on an ENG/VNG
You will have nystgmus in both the horizontal and verticle channels
93
Head turns right -
Utriculpetal for right ear -
left lateral rectus =
Right medial rectus =
Utriculpetal for left ear -
right lateral rectus =
left medial rectus =
Head turns right - **enodolymph move left**
Utriculpetal for right ear - **excitatory**
left lateral rectus = **contracts**
Right medial rectus = **contracts**
Utriculpetal for left ear - **inhibitory**
right lateral rectus = **relaxes**
left medial rectus = **relaxes**
94
Head turns left -
Utriculpetal for right ear -
left lateral rectus =
Right medial rectus =
Utriculpetal for left ear -
right lateral rectus =
left medial rectus =
Head turns left - **enodolymph move right**
Utriculpetal for right ear - **inhibitory**
left lateral rectus = **relaxes**
Right medial rectus = **relaxes**
Utriculpetal for left ear - **excitatory**
right lateral rectus = **contracts**
left medial rectus = **contracts**
95
Define Pendular Nystagmus
The speed of motion of the eyes is the same in both directions
96
Jerk Nystgmus
There is slow & fast phase. The eyes move slowly in one direction and then seem to jerk back in the other direction.
97
# Name the Nystagmus
Pendular Nystagmus
| No distinct fast and slow phases (sinusoidal pattern)
98
# Name the Nystagmus
Torsional/Rotary Mixed Nystagmus
| central or mixed which can indicate
peripheral issues
99
# Name the Nystagmus
Jerk Nystagmus
| Horizontal → typically congenital
Vertical → acquired cerebellar disease
100
Types of Jerk Nystagmus
Can be Down beating, up beating, left beating or right beating
101
What is Alexander's Phenomena
The patient has central nystagmus (center gaze or spontaneous), to determine origin have them gaze towards towards the phase fast of there central nystagmus. if there is a an increase when looking towards fast phase side then have them look the other direction. When looking towards slow phase nystagmus needs to decrease = alexander's phenomenon = peripheral
102
Spontaneous right-beating nystagmus.
When looking right (toward fast phase) → nystagmus is stronger.
When looking left (away from fast phase) → nystagmus is weaker.
Aquired Horizontal Jerk Nystagmus
- Obeys Alex's law
- Peripheral
103
- Left beating Nystagmus
- Central (eyes closed)
- But if you vision allowed and
- nytagmus got better = peripheral
- Nystagmus got worse = central
-
104
Left beating nystagmus
105
**Normal**
- The patient is showing square wave jerks with eyes closed.
- Some normal individuals display square wave jerks, although their peak-to-peak amplitudes rarely exceed 5 deg.
106
Abnormal. There is a **right-beating nystagmus**, with slow phases greater than 6 deg/sec.
107
Left beating nystagmus
- right side affected
- Peripheral - suppresed w/vision
108
Left beating
- right affected
- peripheal
| Ask - confused since there was central Nystgamus
109
* CNS disorder
* The slow phase velocity of the nystagmus does not increase when the patient closes eyes.
* The nystagmus is not suppressed by visual fixation.
110
downbeating nystagmus.
* Central
* Downbeating nystagmus is generally considered to be evidence of a lesion in the cerebellum or lower brainstem.
111
**right-beating nystagmus** in the sitting and supine positions and stronger, persistent right-beating nystagmus in the right-ear-down position.
* Nystagmus was unchanged when the patient was turned on the right side, so it is not due to neck torsion.
* Assume Peripheral but would need calorics to know forsure
112
* right-beating nystagmus with eyes closed that meets criteria “b” and “d”.
* “spontaneous nystagmus”, since its intensity is unaltered by changes in head position.
* assume Periheral would need calorics to know for sure
113
**positional nystagmus with eyes closed**
* Geotropic
* right-beating in the right-ear-down position (geotropic) and left-beating in the left-ear-down position.
* Non-localizing
114
* Direction-fixed positional nystagmus that is in three or more positions.
* Non-localizing.
* If caloric asymmetry = peripheral
* If Calorics abnormal = unclear
115
* direction-changing nystagmus in a single head position.
* Central
116
* Basilar Insufficiency - due to neck torsion
* This patient has a right-beating nystagmus with eyes closed that is strong enough to be abnormal. It is absent when the patient is placed whole body right so it must be due to neck torsion.
117
* geotropic nystagmus with eyes open only.
* Central
* This nystagmus does not enhance or increase with eyes closed. In fact the nystagmus disappears with eyes closed.
118
# All tracings in Same position
PAN - Periodic Alternating Nystagmus
119
# Positonal Testing
* Geotropic
* HC BPPV
* Right side affected
* 8 left and 10 right
| affected side is the stronger side
120
Normal
121
what are the three basic types of nystagmus that are considered as normal (physiological) phenomena?
1. Fatigue Nystagmus
2. Unsustained end point nystagmus
3. Sustained end point nystagmus
122
# Name the test
Used to evalute balance but can also be used to evalute loss of motor coordination
Romberg
123
# Name the test
Test of body proproception (somatosensory) - requires healthy function of the dorsal columns & spinal tract
romberg
124
# Name the test
Also used to meaure degree of functional disequillibrium caused by central vertigo, peripheral vertigo & head trauma
Romberg
125
Romberg Procedure
* Patient removes shoes
* Stand feet together
* arms down & close to body
* first w/eyes open
* Again w/eyes closed
* incrased sway leading to fall = positive romberg
126
What does a positive romberg suggest?
* Positive romberg suggests that loss of coordination is sensory in nature and due to loss of propioception.
* Negative romber w/ataxic suggests ataxia is cerebellar
127
What does it mean if you have a neagtive romberg but your patinet is ataxic?
* If patient is ataxic and romberg is negative this suggests **ataxia is cerebellar**
128
# Romberg
Patients with acute peripheral vestibualr lesion do what?
Pateints with acute periperheal vestibular lesions usually move towards the side of the problem.
129
Pateints with ---- usually move towards the side of the problem.
Pateints with acute periperheal vestibular lesions usually move towards the side of the problem.
130
What is the purpose of the Fukuda Stepping test
Purpose: evaluate labyrinthine function via vestibulospinal reflexes
131
What are the contra-indications for the fukuda stepping test
Patient must be able to maintain balance during eyes- closed romberg testing.
132
fukuda stepping test procedure
* Patient stands with eyes closed hands out stright in front of them
* march in place for 50 steps
* Do not bias patients with auditory /other stimuli
133
what test is a bedside screening test that can detect SCC dysfucntion in all canals & useful for detection of peripheral Vestibulopathy
Halmalgi Head thrust
| https://www.youtube.com/watch?v=Wh2ojfgbC3I
134
# Halmalgi Head thrust
What occurs in abnormal VOR
Re-fixation saccades occur in those with abnormal VOR
135
Name the types of re-fixation saccades
* Covert = saccades occur during the headmovement; difficult to impossible to see with the naked eye.
* Overt = Saccades that occur after the head movement; can be seen with the naked eye
136
# Name the re-fixation saccades
Saccades that occur after the head movement; can be seen with the naked eye
Overt
137
# Name the re-fixation saccades
saccades occur during the headmovement; difficult to impossible to see with the naked eye.
Covert
138
what is a normal result of the halmalgi head thrust
Normal individual will exhibit no corrective/re-fixation saccades
139
what is an abnormal result of the halmalgi head thrust
Impaired individuals will exhibit re-fixation saccades in the direction of the lesion.
140
what test can detect SCC dysfucntion in all canals & useful for detection of peripheral Vestibulopathy
Halmalgi Head thrust
141
what is the Halmalgi Head thrust
HHT is a bedside screening test that can detect SCC dysfucntion in all canals & useful for detection of peripheral Vestibulopathy
142
what does the Halmalgi Head thrust test for
detect SCC dysfucntion in all canals & useful for detection of peripheral Vestibulopathy
143
what test evalutes the status of the patients velocity storage integrator
The headshake evalutes the status of the patients velocity storage integrator
144
The head shake test evalutes what?
The headshake evalutes the status of the patients **velocity storage integrator**
145
Headshake procedure
* Fitted with VNG goggles Vision denied
* shakes head at rate of 2hz for 20 sec
* after 20sec head is abrupt;y stopped and patients opens eyes
* Look for nystgmus post head shake or is pre-existing nytsgmus is worse
146
Normal Head shake
Norma= no post headshake nystagmus
147
Abnormal Headshake
Abnormal
* post headshake nystagmus
* enchanced pre-existing nystgmus post head shake
148
what does it mean if we have an abnormal headshake?
* If post headshake nystgmus = strong indicator the vestibular system is not dynamically compensated
149
What are the 3 main methods that you can transform eye movements into electrical signals to be analyzed by computers?
1. Electro-oculography (EOG/ENG)
2. Infrared Video - Oculography (VOG/VNG)
3. Scleral Search coils
150
How can EOG/ENG track eyes?
Via CRP
- the eyeball cornea + polarized & Retina - polarized
- creats a steady electrical potential field that may be detected with the eyes in total darkness and or with eyes closed
151
For EOG/ENG impedance needs to be
impedance need to be <10,000 ohms; inter-electrode impedance <3,000 ohms
152
explain how Infrared Video Oculography works
* make use of pupil localization technology & reflective nature of corneal surface to calculate pupil position & angle of gaze
* Goggles contain infrared diodes to illuminate the eyes and reflects the image of the eyes into a pair of camera for recording
* infrared light is not visable to human only to system
153
* Coils are embedded into a tighly - fitting contact lens
* lens is surgically implanted
* alternating magnetic fields are generated around eye though electromagnetic induction
Scleral Search Coil
154
Vestibular tests are a test of ____
Vestibular tests are tests of function
155
What is the purpose of vestibular testing?
The purpose of vestibular testing is to determine if a symptom is caused by the inner ear (peripheral), by the brain (central) or mixed or other
156
Pre Test instructions
* when possible refrain from medication use for at least 12 hours
* Don't eat big meal prior to testing
* wear comfortable clothing
* Remove eye makeup prior
157
Abbreviated Vestib Case History
1. Description
2. Timing
3. Frequency
4. Provoking Factors
5. Associated symptoms
6. medical history
7. medications
| DTF PAMM
158
# Abbreviated Vestib Case History
Description
* describe what you're feeling (why are you here?)
* Open - ended. Don't lead or bias
* Differentiate Vertigo VS Non- vertigo **
| Vertigo typically peripheral
159
# Abbreviated Vestib Case History
Timing
* How long does it last
* is it continious
* Short (sec,min) , intermediate (min - hrs) or long (>24 hrs)
160
# Abbreviated Vestib Case History
Frequency
how often
161
# Abbreviated Vestib Case History
Provoking
* When do you attacks occur
* with what?
* Change in head, neck, position, headaches, movement, loud noises, ear pressure, diet, visual stimuli, stress etc.
162
# Abbreviated Vestib Case History
Associted Symptoms
* Hearing loss
* tinnitus
* aural fullness
* pain
* headache
* Visual disturance
* facial or motor weakness
* autonomic symptoms (nausea, sweating)
163
# Abbreviated Vestib Case History
Medical History
* Neuropathy (diabetes)
* Vascular disease (stroke, heart disease)
* Motion Sickness
* Migraines
* seizures
* ear surgerys
* Psychiatric Disease (anxxiety,depression & panic)
Other
* famioly history
* progression
* severity level
164
# Abbreviated Vestib Case History
Medications
* IV antibiotics, radiation therapy, chemo
* Anti axiety, Diuretics
* alcohol or durg use
165
ENG/VNG Battery
Oculomotor exam
* Calibration
* spontaneous
* Gaze
* saccades
* Pursuit
* Optokinetic
Positioning exam
* Dix Hallpike
* Static Positional (supine)
Caloric irriagtions
* right warm
* left warm
* right cool
* left cool
166
# vestibular assessment
Postional Maintence (gaze holding)
* Center (aka spontaneous), left, right , up, down
* Performed with & without fixation
* requires multiple systems
167
Present Center gaze/sponatneous =
Center gaze/sponatneous = non-localizing
168
Present Eccentric gaze
Right,left,up & down
Eccentric gaze
Right,left,up & down
* Central
* Unless center gaze = non local
169
Saccades
Primarily volitional, gets the fovea to target, fastest movements
* Saccadic eye movements are voluntary (you control them), and their purpose is to move the fovea (the center of sharp vision) to a new target. These movements are extremely fast compared to other types of eye movements (like smooth pursuit or vergence).
170
Saccades parameters for interpretation
Velocity - speed of eye movement
Latency - how long after target moves does eye move
Accuracy - does the eye reach teh target
- undershoot
- overshoot
171
for saccades what is the normative range?
normative range denoted by white area shaded is abnormal. Abnormal should be consistenly abnormla >50% of recording
172
# what is the saccadic accuracy abnormaility
Saccadic hypometria (undershoots)
173
# what is the saccadic accuracy abnormaility
Saccadic hypermetria (overshoots)
174
# Vestibular assessment
Pursuit tracking
* Movement of the eyes while tacking an object
* correlates with OPK
* Involves ipsilateral cerebellar hemisphere, brain stem, or pariero - occiptal region
175
what the parameters for pursuit interpretaion
Gain: eye movement relatiev to target movement
Phase: Rightward versus leftward
S: Some systems include # of saccades
| GPS
176
# Vestibular Assessment
Optokinetic (OPK/OKN)
* occurs when you track a moving visual scene
* Unlike smooth pursuit, the OKR involves tracking a moving field
* Combination response slow phase: The eyes track the movement of the field.
Fast phase: The eyes make quick jumps (saccades) to reset position and catch up with the moving field.
* **Weakest subtest in ocular motility battery**
* Should involve movement in both central and peripheral visual fields
177
OPK Parameters for Interpretation
**Symmetry = rightward versus leftward**
* Gain normative values exist but less sensitive due to numerous different stimuli and parameters
* failure to increase eye speed would denote central abnormality
178
Normal & Abnormal VOR
Normal VOR = eyes remain on target,
Abnormal VOR = eyes slip off target and must make corrective saccade back
179
VOR is useful for
Useful in detecting unilateral or bilateral peripheral hypofunction. Abnormal to side with corrective saccade
180
The most common cause of vertigo in the elderly.
BPPV
181
Assumed to be the result of displaced otoconia from the utricle settling in the posterior SCC (or anterior SCC).
BPPV
182
BPPV criteria
1. **Latency** Delayed onset of vertigo and nystagmus begin 1 or more seconds after the head is tilted toward the affected ear, and increase in severity to a maximum.
2. **Duration** less than 1 minute. Nystagmus reduces gradually after 10 to 40 seconds
3. **Linear-rotary nystagmus**. The nystagmus is linear-rotary with the fast phase beating toward the undermost ear or upward when the patient’s gaze is directed toward the uppermost ear.
4. **Reversal**. When the patient returns to the seated position, the vertigo and the nystagmus may reoccur in the opposite direction and less violently.
5. **Fatigability**. Constant repetition of this maneuver will result in ever lessening symptoms.
183
# BPPV
Latency
Vertigo & nystagmus begin 1 or more seconds after the head is tilted toward the affected ear, and incrase in severity.
- delayed latence
184
# BPPV
Duration
Duration is less than 1 minute
- nystagmus reduces graudally after 10 to 40 seconds and ultimately will stop
185
# BPPV
Linear - rotary nystgamus
The nystsgamus is rotary with geotropic or ageotropic
186
# BPPV
Reversal
when the patient returns to the seated position, the vertigo and the nystagmus may reoccur in opposite direction and less velocity
187
# BPPV
Fatigability
Constant repetition of this manuver will result in ever lessening symptoms.
188
Supine Head roll procedure
* supine head center
* Supine head turned right
* supine head turned left
* whole body left
* repeats eye open & closed for left and right side
30 seconds in each position
189
Positional nystgamus is pathological if
1. it changes direction in any head position OR
2. It is persistent in at least 3 head positions OR
3. It is intermittent in all head positions OR
4. Its slow phase velocity exceed. 5 ENG deg/sec in any head position
190
what do Dix - hallpike and supine head roll assess?
Dix hallpike - BPPV in AC/PC
Supine - BPPV in HC
- Looks for any asymmetry in vestibular system
191
Otoconia freely moving in the endolypmph within in SCC.
- Delayed onset & Fatigues over time
- Geotopic in HC
Canalithiasis
192
Otoconia adhered to the cupula within the SCC or on the opposite side of the cupula.
- immediate onset
- little/no fatigue
- ageotropic
Cupulolithiasis
193
Canalithiasis
Otoconia freely moving in the endolypmph within in SCC.
- Delayed onset & Fatigues over time
- Geotopic in HC
194
cupulolithiasis
Otoconia adhered to the cupula within the SCC or on the opposite side of the cupula.
- immediate onset
- little/no fatigue
- ageotropic
195
Dix - hallpike maneuver
assess for AC/PC BPPV
abnormaility = torsional nystgamus w/subjetive report (vertigo)
196
Positional Tests (supine head roll)
* Assess HC BPPV
* abnormality = linear geotriopic or ageotropic
197
Treatment for BPPV
Habituation Techniques
particle repositiong
surgical Intervention
198
Anterior/Posterior BPPV treamnt
**Epley**: Most common for AC/PC canalithiasis bppv
**Semont**: Most common for P/C & **cupulolithiasis**, A/C & P/C
199
Horizontal BPPV treatment
BBQ Roll: treats HC BPPV
- geotropic
200
# Pursuits
Impairment in both directions →
Impairment in one direction →
Impairment in both directions → central
Impairment in one direction → usually same sided lesion (stroke on R side → good left tracking, poor right)
- always central
201
# Peripheral or central
Saccades
Central
202
# Peripheral or central
Optokinetic (OKN)
Optokinetic nystagmus (OKN) abnormalities are generally of central origin.
203
Caloric Tests cold and warm air temps
Air
cool = 24oC;
warm = 50oC
204
Caloric Tests cold and warm water temps
Water
cool = 30oC;
warm = 44oC
205
COWS
CO: Cold Opposite
WS: Warm Same
206
For Calorics Nystagmus results are calculated to obtain what?
Nystagmus results are calculated to obtain **Unilateral Weakness and Directional Preponderance**
Only horizontal canal
207
Advatanges of caloric tests
* evelaute each ears horizontal canal separately
* Test low frequencies and majorty of vestibualr disorders affect low frequencies.
* By putting a stimulus in the ear canal you are able to stimulate the horizontal SSC of that side which changes the neural activity. (changing endolymph)
208
Disadvatanges of caloric tests
* Results are affected by the status and barriers of the middle ear. (temp transfer)
* Only tests LF's it simulates movements of the head that are slower than those that are natural movements.
* Calorics are not site specific. They only evaluate the horizontal canal and superior vestibular nerve.
209
Caloric Unilateral Weakness
Equation & passing criteria
Normal: Under 25%
Abnormal: Above 25%
210
# Name the test type
Directional Preponderance
Calorics
211
Caloric Directional Preponderance
Equation & passing criteria
Normal: below 35%
Abnormal: above 35%
212
# Name the test type
Unilateral Weakness
Calorics
213
# Normal or Abnormal & why
Normal fixation, when the lights turn on nystagmus gets smaller.
* Because Normal cerebellar function is able to reduce nystagmus w/ fixation suppression.
214
# Normal or Abnormal & why
Abnormal, light turns on and nystagmus does not change.
Failure of fixation suppression
215
A clinically significant unilateral weakness is defined as an interaural difference in____
A clinically significant unilateral weakness is defined as an interaural difference in **mean maximum SPV of 20-25% or greater.**
216
what is the interpretation of A clinically significant unilateral weakness (greater than 25%)
The interpretation of these findings is that the **patient is demonstrating evidence of a significant peripheral vestibular system deficit**.
217
**true** COWS inverstion is indicative of what?
Brainstem disease very rare but you need to rule out technical error and ME pathology
218
perversion of COWS is indictive of
1. Brainstem
219
# True or False
Calorics are site specific
FASLE could be
* Horisonal
* SVN
220
What is the caloric test order
RW LW LC RC
or
RC LC LW RW
| basically keep the colds and warms together
221
What does the Total number (total reponses) tell you?
The total number tells you if its hyperactive/hypoactive responses and bilateral caloric weakness
This is the total eye speeds (all reponses added together)
Hyper = greater than 140
Hypo = less than 26
* not responsing as it should bilteral vestbualr loss
222
what total response is indicitive of bilateral vestibular loss?
Hypoexcitability = less than 26
**not responsing as it should = signs of bilteral vestbualr loss**
223
UW can be caused by damage of the what?
UW can be caused by damage of the **vestibular end organ, superior CN8, or root entry zone of the CN8**
224
A DP exists when what?
A DP exists when **the nystagmus response is greater in one direction than in the other.**
225
A clinically significant directional preponderance is defined as ___
A clinically significant directional preponderance is defined as **a 30% or greater difference** in intensity of the maximum SPV between the two right beating responses and the two left beating responses.
226
DP is useful when
Useful when you have one eye already beating a certain way or when caloric data is not in agreeance with COWS.
- DP by itself is not useful.
227
DP is most often seen in patients who ....
A DP is most often seen in patients who have a **strong spontaneous nystagmus.**
228
DP patients who have a strong spontaneous nystagmus demonsttrate what caloric response?
Patients with spontaneous nystagmus tend to show **stronger reactions** to caloric stimulation that aligns with & beats **towards** their existing spontaneous nystagmus direction.
* This response is expected because the stimulated side is likely already more active or dominant.
229
# True or False
For Fixation Suprression studies have shown varying results in how effectively people can suppress this eye movement using visual fixation.
TRUE
Different research studies have shown varying results in how effectively people can suppress this eye movement using visual fixation.
* The degree to which caloric nystagmus is attenuated by visual fixation has been reported in the literature as varying depending upon which laboratory data set is used.
230
# Calorics
Fixation index in normal individuals should be able to suppress caloric-induced nystagmus_____
It is suggested that physiologically normal individuals should be able to suppress caloric-induced nystagmus **60% or more with visual fixation.**
231
What is Caloric Inversion?
Caloric inversion is defined as an entire caloric response that beats in the opposite direction to that expected.
**DOES NOT FOLLOW COWS**
232
Caloric inversions are __ and have been associated with ___
Caloric inversions are **rare** and have been associated with **brain stem disease**.
233
what is used rimarily when bi-thermal irrigations are very low or to help confirm diagnosis of BVL though rotary chair is gold standard?
Ice Water Calorics
234
What can also be useful for confirmation of ablative procedures such as gentamycin injections and vestibular nerve section?
Ice Water Calorics
235
Ice Water is used primarly when?
Used primarily when **bi-thermal irrigations are very low or to help confirm diagnosis of BVL** though rotary chair is gold standard
236
Ice Water is also useful for confirmation of what?
seful for confirmation of ablative procedures such as **gentamycin injections and vestibular nerve section**
237
How do you conduct Ice water Calorics?
No universally standardized procedure or temperature but typically a single bolus approximately **2cc of ice water (~18℃)** is delivered to the ear
* traditional caloric position **(Supine, head elevated 30deg, vision denied)** or supine head rotated and held before returning to caloric position or prone
238
Name the main uses for Ice Water Calorics?
* confrim BVL
* Detect is any damage occured during any procedures (surgery was sucess or not)
* determine any residual vest function remaining due to toxicity
* when alternate bithermal caloric testing (ABB) yields no recordable responses.
239
Describe the traditional caloric position
**Supine, head elevated 30deg, vision denied**
* HSCCs are now perpendicular to ground
240
what testing has been primarily used for instances when alternate bithermal caloric testing (ABB) yields no recordable responses.
ICE WATER CALORICS
241
# True or False
The identification of residual vestibular function ( even minimal) in an impaired system is important for several reasons.
TRUE
242
both sides are irrigated simultaneously
Bilateral irrigation
* both sides are irrigated simultaneously
243
a water filled bag is used instead of water
Balloon test
* a water filled balloon is used instead of water
244
used to confirm complete loss
Ice water caloric
* used to confirm complete loss
245
what is has greater variabiliity air or water?
**Air** has greater variability than water
246
what is has the least amount of variabiliity air or water?
Water
* Water is more consistent; it is less prone to technical errors like bad irrigation.
247
Caloric Irrigations
* Allow for ‘ear-specific’ evaluation of vestibular system via VOR
* Patient must be placed in the ‘caloric position’
* Performed with air or water (warm & cool stimulation)
248
Air:
Temps, time, record time & protocol
Air:
* Warm 50°C, Cool 24°C
* 1 minute (flow 8L)
* Record for at least 90 seconds. while Reverse protocol. TASKING!
* Measure the peak SPV of the nystagmus generated
* C.O.W.S. mnemonic (for supine irrigations)
* Provide Target of nystmus is still present so you can stop nytsgmus
| Tasking is so they dont supress nysgmus while recording
249
Water:
Temps, time, record time & protocol
Water:
* Warm 44°C, Cool 30°C
* 30 seconds (250mL)
* Record for at least 90 seconds. while Reverse protocol. TASKING!
* Measure the peak SPV of the nystagmus generated
* C.O.W.S. mnemonic (for supine irrigations)
* Provide Target of nystmus is still present so you can stop nytsgmus
| Tasking is so they dont supress nysgmus while recording
250
Pros to water
* **faster**
* **more reliable** (better test/re-test, less prone to inadequate stimulation from cerumen occlusion, hitting canal wall, etc)
251
Pros to air
* more tolerable
* less messy
* can be done on those w/ various middle ear pathology that would preclude water (otitis externa, PE tubes, etc)
252
Reverse protocol
* The test is conducted in a sequence that ensures each successive irrigation triggers nystagmus in the opposite direction of the previous one.
* Allow the previous nystagmus response to fully subside.
* Approx 5 mkinutes inbetween each caloric
Example
Standard Reverse Protocol:
Right Warm (RW) → Left Warm (LW) → Left Cool (LC) → Right Cool (RC)
Option 2 Reverse Protocol:
Right Cool (RC) → Left Cool (LC) → Left Warm (LW) → Right Warm (RW)
253
Warm stimulation =
Warm stimulation = decreased endolymph density = ampullopetal flow = excitatory response for test ear
254
Cool stimulation
Cool stimulation = increased endolymph density = ampullofugal flow = inhibitory response for test ear
255
____ = increased endolymph density = ampullofugal flow = inhibitory response for test ear
**Cool stimulation** = increased endolymph density = ampullofugal flow = inhibitory response for test ear
256
____ decreased endolymph density = ampullopetal flow = excitatory response for test ear
**Warm stimulation** = decreased endolymph density = ampullopetal flow = excitatory response for test ear
257
* Comparison of total responses (sum of all) from both ears
* Equal or less tham 26 deg/s
Hypo-Responsive
258
* Comparison of total responses (sum of each ear) individually
* Equal or greater then 140 deg/s
Hyper-Responsive
259
# Total Response
* MAY indicate bilateral vestibular loss
* Non-localizing finding (can be central or peripheral)
Hypo-responsive
260
Hypo-Responsive Criteria for interpretation
* Comparison of total responses (sum of all) from both ears
* < 26 deg/s
* Significance: MAY indicate bilateral vestibular loss
* Non-localizing finding (can be central or peripheral)
* Caution: Alertness of patient (fatigue, meds), appropriate tasking
261
# Total Response
central (typically cerebellar); rare finding
Hyper-Responsive
262
Hyper-Responsive
Criteria for interpretation
* Comparison of total responses (sum of each ear) individually
* >140 deg/s total RE responses, >140 deg/s total LE responses
* Significance: central (typically cerebellar); rare finding
* Caution: most common w/ bad calibration, abnormal middle ear (mastoid cavity, perforation, PE tube) or bad irrigation temperature
263
Caloric Limitations:
* Only tests VOR at very low frequency
* Only tells us about function of HSCC & SVN
* Variable & slightly uncomfortable
* Can’t be performed / evaluated on some patients (Perf, PEtube)
* Can infer but not definite for bilateral vestibular loss (BVL)
* can not determine the level of functional compensation
264
# VOR
If you accelerate your head to the left which way do the eyes and endolymph go?
head left
Endolyph & Eyes right
265
Describe the image for vHIT
**Green:** Head is at rest - being held into place = no movement
**Purple**: The head is thrust rapidly, - you are seeing an *equal and opposite* reaction at a large magnitude - since this is during teh head thrust
**#3** : Immediate/abrupt stop of head
**Pink:** after you stop you will continue to see and equal and opposite reaction on a lower magnitude and will continue to decraese until it levels out since head is at rest once again.
266
What are the three phases of vHIT?
1. head impulse starts (head exceeds 20 deg/sec)
2. Peak Velocity or Acceleration (A/V meet max value)
3. Head Impulse end (Stop 0 deg/sec) & rebound is seen
267
____ bedside screening test that can detect semicircular canal dysfunction in all canals, useful for detection of peripheral vestibulopathy
**Head Impulse Test** is a bedside screening test that can detect semicircular canal dysfunction in all canals, useful for detection of peripheral vestibulopathy
268
Head Impulse Test is a bedside screening test that can detect what?
Head Impulse Test is a bedside screening test that can detect **semicircular canal dysfunction in all canals, useful for detection of peripheral vestibulopathy**
269
HIT detects ____ dysfunction in ____ . Detects ____
HIT detects **SCC** dysfunction in **all canals**. Detects **peripheral vestibulopathy**
270
What is a abnormal finding for vHIT?
Altered VOR gain and presence of re-fixation or catch-up saccades in abnormal individuals during head thrust
Reduced gain = BVL
Overt & covert = Uncompendated UVL
Covert = Compensated UVL
All peripheral
271
# True or False
Re-fixation saccades occur in those with normal VOR
FALSE
Re-fixation saccades occur in those with abnormal VOR
Covert - occur during head movements (cannot see with our naked eyes)
Overt - occur after head movement (can see with our naked eyes)
272
Saccades that occur during the head movement & difficult to see with eye
Covert
273
Saccades that occur after the head movement & seen with the naked eye
Overt
274
Covert Saccades
Saccades that occur during the head movement; difficult to impossible to see with the naked eye
275
Overt Saccades
Saccades that occur after the head movement; can be seen with the naked eye
* present when UVL is uncompensated
276
How to preform vHIT
* patient focuses on fixed point
* Move head fast (200+ deg/sec) 10-20 deg range only
* The key is the quickness, you do not have to go far, just fast.
* Unpredictable movements
* Can do on patients down to 10 mo. old.
277
Youngest you can do vHIT
10 mos
278
What are the two things analyzed with vHIT data?
**Gain** = eye movement relative to head movement
Normative >0.7 some systems, >0.8 other systems
**Presence** of re-fixation **saccades** (overt and covert)
279
vHIT is typically performed in at least ___ plane but can also do ___ and ___
Typically performed in at least horizontal plane but can also do LARP and RALP
280
Occur during head movement
Compensated lesion
Covert
281
Occur after head movement
Uncompensated lesion
Overt
282
What all does vHIT measure?
Gain/VOR gain
Presence of Saccades
Measures each canal separately.
283
Normative Gain for vHIT
Normative greater or equal to 0.7 some systems,
284
vHIT Clinical use benefits
* Functional Measure
* Eval High Frequencies
* High Sensitivity to Vestibulopathy
* Canal specific info
* Track VRT Progess & Compensation
285
vHIT limitations
* Only HF (miss LF vestib deficits)
* Not sensitive to dysfunction 2nd to Mernieres
* Technique challenging
286
# vHIT
Normal or Abnormal & why?
Normal, no overt or covert saccades and gain is normal
287
# vHIT
Normal or Abnormal & why?
Abnormal Unilateral vestibular loss, uncompensated
* Right vhit normal
* Left vHIT shows both covert and overt saccades -- left sided UVL
288
# vHIT
Normal or Abnormal & why?
Abnormal Bilateral VL
* covert saccdes are seen in both left & right
* Eye have no gain then saccdes
289
# stand for
HINTS
H.I : Head Impulse
N: Nystagmus
T.S: Time skew
290
HINTS is used to be able to distinguish between ____ & ______ by using bed side oculomotor tests
HINTS is used to be able to distinguish between **Strokes** & **benign acute vestibulopathies** by using bed side oculomotor tests
291
# Peripheral or Central
Onset: Only Sudden
Severity: Intense
Pattern: Intermittent
Worse w/movement: Yes
Nausea: Frequent
Nystagmus: Horizontal
Fatigue: Yes
HL/Tinnitus: May occur
CNS signs: NO
Peripheral
292
# Peripheral or Central
Nystagmus: Horizontal
Peripheral
293
# Central or Peripheral
Onset: Sudden or gradual
Severity: Less Intense
Pattern: Constant
Worse w/movement: Variable
Nausea: Variable
Nystagmus: Vertical or multi directional
Fatigue: No
HL/Tinnitus: No
CNS signs: Usually
Central
294
Codes for vHIT
Currently, as of 2020, **no CMS approved codes** for vHIT testing
295
Concussion signs frequently do not appear on _____
Concussion signs frequently do not appear on **CT or MRI**
296
Slow phase is driven by what
Slow phase is driven by the ears (peripheral vestibular)
297
Fast phase is driven
Fast phase is driven by the CNS (central)
298
Nystagmus beats away
Nystagmus beats away from an inhibited/affected ear
299
Describe the vestibular audiogram
Very Low F: Calorics
Low & Mids: Rotary Chair & hit
High F: Active head rotation
300
Active Rotation Example
Vestibulo-autorotation test (VAT/Vorteq)
&
Headshake can be active or passive
301
Pros of Rotary testing
Rotary testing is a more natural speed of head movement/ VOR function & more tolerable than calorics
302
Where is the axis of rotation?
The axis of rotation for rotary chair is **centered between both labyrinths (bilateral stimulation)**
303
CCW rotations
CCW rotations = left-beating nystagmus
- (left HSCC excitatory, right HSCC inhibitory effect)
- CCW is rotating to left
| CCW - couterclock wise
304
CW rotations
CW rotations = right-beating nystagmus
* (right HSCC excitatory, left HSCC inhibitory effect)
* CW rotatess to the right
305
Rotatary Chair focus on what phase?
RC ONLY Focuses on Slow phases of nystagmus
* Fast phases are tossed out for analysis .
* **All slow phases are then combined in a sinusoidal form for analysis**.
306
Rotary chair can be used to examine the
Rotary chair can be used to examine the **HSCC, central systems and vestibular nuclei**.
307
Clinical application of rotary chair
* Evaluates bilateral vestibular loss (BVL); or patient w/ low calorics
* monitor for ototoxicity (vestibulo-toxicity)
* evaluate for CNS disorders
* Tells us degree of Central compensation
* guides Rehab therapy decisions
* evaluate vestibular function on those who can’t undergo caloric testing or w/ calorics that can’t be reliably compared
308
Step Velocity examines what
The vestibular system’s central velocity storage
309
Step Velocity Procedure
* Patient is quickly accelerated to a constant velocity and rotated in one direction (CW or CCW) for about 1 minute
* Typically velocity used is either 60, 100 or 200 deg/s
* Velocities > 200 deg/s= more ear-specific
* stopped abruptly and post-rotary nystagmus observed for about 1 minute
* repeated for the opposite direction (CW or CCW)
* pre & post-rotary nystagmus are compared
Abnormal gain or duration patterns (called time constants) suggest specific deficits in the vestibular system
310
Step Velocity Test
* Performed in complete darkness with tasking
* Initial stimulation should show a burst of nystagmus beating **toward** the direction of rotation
* nystagmus will dispear over time as the subject maintains constant velocity
* stopped and their will be a second burst of nystagmus but in opposite direction
Both the gain and duration of the per-rotary and post-rotary nystagmus are measured
Summary
* Darkness - rotate = burst N - Nysta stops since rotation constant - Stopped = burt N but opposite
311
Step Velocity Measurement Parameters:
**Gain** = Initial peak gain SPV of nystagmus
* Measured pre & post-rotary
Reduced gain = Central, bilateral or unilateral vestibular disorders
* Greater rotational velocities (>200 deg/s) = more ear-specific (due to larger excitatory response)
**Time Constant** = Time required for nystagmus to decay to 37% of original peak gain SPV
* Measure pre & post-rotary
* Variable dependent on velocity of chair
* > 10 seconds = normal
shortened time constants = Central, bilateral or unilateral vestibular disorders
312
Step Velocity Reduced gain
Central, bilateral or unilateral vestibular disorders
313
Patient is asked to fixate on a point of light projected in front of them on the enclosure wall while being rotated sinusoidally. Visual target travels at same speed as chair.
Visual Suppression (Fixation) VFx:
314
Visual Suppression (Fixation) VFx
* fixate on point while being rotated in the chair sinusoidally. (visual is same speed as chair)
* Should be able to maintain focus on the light which will reduce the vestibular induced nystagmus.
* Failure to fixate = central sign (occipital, parietal lobe or flocculus of cerebellum)
* No tasking because there is a target
* Ensure good vision
315
# VFx
Failure to fixate =
Failure to fixate = central sign (occipital, parietal lobe or flocculus of cerebellum)
316
Visual Enhancement (VVOR):
* Performed by projecting OPK stimulus on wall of rotary chair enclosure.
* patient is rotated sinusoidally and OPK stimulus does not move.
* Pursuit, OPK, and VOR systems contribute.
* **Test is done if the patient has low gain for traditional SHA tests**.
317
Rotational Chair Limitations:
* Tests VOR at low & mid frequencies
* Only shows Function of HSCC and SVN, + CNS & VN (no info about function of otoliths, IVN, or other SCC’s
* Can’t perform on claustrophobic or obese patients.
* poor ear specificity, will miss mild-moderate unilaterallosses
318
Active Head Rotation (AHR) Procedure
* Goggles
* Metronome
* Patient would actively shake their head “yes” and “no” to the beat of a metronome over a specified frequency range
* Could also be performed with Dynamic Visual Acuity Test (DVA or DVAT)
319
Active Head Rotation Test (AHR)
* Used to measure VOR during rapid head movement where visual stability might be impaired in a patient with VOR deficit.
* assesses moderate - high frequency movements not assessed by rotary chair
* Cheaper
320
“SOME CENTER GAZE NYSTAGMUS OBSERVED: EYES BEAT TO THE PATIENT’S LEFT (INCREASED WITH LEFTWARD GAZE, ABATES WITH RIGHTWARD GAZE).”
“DEMONSTRATES CORRECTIVE SACCADE WITH RIGHT HEAD IMPULSE, NONE TO LEFT.”
Alexsnders Phenomena w/ Right side vestibulopathy peripheral
Spontaneous Nystagmus & left beating nystagmus
* Nystagmus beats away from affected ear
* Alexanders Phenomena because
* Gaze in the direction of the fast phase, Nystagmus Increases = peripheral
* The patient has central nystagmus (center gaze or spontaneous), to rule out if it is peripheral or central have them gaze to the left and right, if there is a an increase on one side then alexander's phenomenon = peripheral
HIT
* VOR in direction of lesion of lesion you get corrective saccades in the same direction of the vestibular loss = right vestibular loss
* Right side vestibulopathy - because corrective saccades to right & left beating nystagmus
321
Left: Gain a little low but mostly normal
* since the good ear may have reduced its gain (static compensation)
Right: covert & overt saccades
* uncompensated right sided vestibular loss
322
SN: Present Nystagmus - eliminate w/fixation & left beating= peripheral & right affected side
HS: When you tax the system with a headshake you are amplifying the asymmetry
the more you work system the more noticeable it will be
SR: Normal
323
Normal
324
Normal
win/ normal gain
325
Horizontal Left beating Nystagmus
no torsional = not A/P BPPV
326
* Peripheral and right side affected
Diagnosis: Acute Uncompensated Right Vestibular Loss
Treatment: Vest rehab w/PT
327
Lateral: Covert & Overt saccades, Low Gain
Posterior: Covert & Overt saccades, Low Gain
Anterior: Covert & Overt saccades, Low Gain
Looking more global
328
Hypoactive - BVL
329
Bilateral Vestiblar Loss
* reduced gain on RC
* Hypoactive
330
Majority is within normal range
