Midterm Ocular Motility Testing Flashcards
Vestibular tests are a test of ____
Vestibular tests are tests of function
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
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
Abbreviated Vestib Case History
- Description
- Timing
- Frequency
- Provoking Factors
- Associated symptoms
- medical history
- medications
DTF PAMM
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
Abbreviated Vestib Case History
Timing
- How long does it last
- is it continious
- Short (sec,min) , intermediate (min - hrs) or long (>24 hrs)
Abbreviated Vestib Case History
Frequency
how often
Abbreviated Vestib Case History
Provoking
- When do youo attacks occur
- with what?
- Change in head, neck, position, headaches, movement, loud noises, ear pressure, diet, visual stimuli, stress etc.
Abbreviated Vestib Case History
Associted Symptoms
- Hearing loss
- tinnitus
- aural fullness
- pain
- headache
- Visual disturance
- facial or motor weakness
- autonomic symptoms (nausea, sweating)
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
Abbreviated Vestib Case History
Medications
- IV antibiotics, radiation therapy, chemo
- Anti axiety, Diuretics
- alcohol or durg use
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
vestibular assessment
Ocular motility tests
- Spontaneous (center gaze)
- Gaze (horizontal, vertical)
- saccades
- Pursuit (horizontal, vertical)
- Optokinetic
- VOR
- vergence is not perfomed
vestibular assessment
Postional Maintence (gaze holding)
- Center (aka spontaneous), left, right , up, down
- Performed with & without fixation
- requires multiple systems
Present Center gaze/sponatneous =
Center gaze/sponatneous = non-localizing
Present Eccentric gaze
Right,left,up & down
Eccentric gaze
Right,left,up & down
* Central
* Unless center gaze = non local
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).
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
for saccades what is the normative range?
normative range denoted by white area shaded is abnormal. Abnormal should be consistenly abnormla >50% of recording
what is the saccadic accuracy abnormaility
Saccadic hypometria (undershoots)
what is the saccadic accuracy abnormaility
Saccadic hypermetria (overshoots)
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
what the parameters for pursuit interpretaion
Gain: eye movement relatiev to target movement
Phase: Rightward versus leftward
S: Some systems include # of saccades
GPS
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
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
VOR
- Not a distinct subtest of ENG/VNG
- Indirectly measured via caloric irrigation
- Can be evaluated bedside by Halmagyi Head Thrust / Head Impulse Test
Normal & Abnormal VOR
Normal VOR = eyes remain on target,
Abnormal VOR = eyes slip off target and must make corrective saccade back
VOR is useful for
Useful in detecting unilateral or bilateral peripheral hypofunction. Abnormal to side with corrective saccade
ENG Test Battery
What’s included in eng test battery?
Positioning Test
* The Dix-Hallpike Maneuver
* The Side-Lying (DH) Maneuver
The most common cause of vertigo in the elderly.
BPPV
Caused by canalithiasis or cupulolithiasis of the posterior SCC (or anterior SCC).
BPPV
Assumed to be the result of displaced otoconia from the utricle settling in the posterior SCC (or anterior SCC).
BPPV
BPPV criteria
- 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.
- Duration less than 1 minute. Nystagmus reduces gradually after 10 to 40 seconds
- 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.
- Reversal. When the patient returns to the seated position, the vertigo and the nystagmus may reoccur in the opposite direction and less violently.
- Fatigability. Constant repetition of this maneuver will result in ever lessening symptoms.
BPPV
Latency
Vertigo & nystagmus begin 1 or more seconds after the head is tilted toward the affected ear, and incrase in severity.
- delayed latence
BPPV
Duration
Duration is less than 1 minute
- nystagmus reduces graudally after 10 to 40 seconds and ultimately will stop
BPPV
Linear - rotary nystgamus
The nystsgamus is rotary with geotropic or ageotropic
BPPV
Reversal
when the patient returns to the seated position, the vertigo and the nystagmus may reoccur in opposite direction and less velocity
BPPV
Fatigability
Constant repetition of this manuver will result in ever lessening symptoms.
Positonal Testing 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
Positional nystgamus is pathological if
- it changes direction in any head position OR
- It is persistent in at least 3 head positions OR
- It is intermittent in all head positions OR
- Its slow phase velocity exceed. 5 ENG deg/sec in any head position
BPPV
name the positonal tests
Dynamic - Dix-hallpike manuver
Static - Supine head roll
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
Otoconia freely moving in the endolypmph within in SCC.
- Delayed onset & Fatigues over time
- Geotopic in HC
Canalithiasis
Otoconia adhered to the cupula within the SCC or on the opposite side of the cupula.
- immediate onset
- little/no fatigue
- ageotropic
Cupulolithiasis
Canalithiasis
Otoconia freely moving in the endolypmph within in SCC.
- Delayed onset & Fatigues over time
- Geotopic in HC
cupulolithiasis
Otoconia adhered to the cupula within the SCC or on the opposite side of the cupula.
- immediate onset
- little/no fatigue
- ageotropic
BPPV Incidence
- Posterior C BPPV - Most common 90-95%
- Horizontal canal 2nd MC 2 - 10%
- Anterior Rare 1-3 %
Dix - hallpike maneuver
assess for AC/PC BPPV
abnormaility = torsional nystgamus w/subjetive report (vertigo)
Positional Tests (supine head roll)
- Assess HC BPPV
- abnormality = linear geotriopic or ageotropic
Treatment for BPPV
Habituation Techniques
particle repositiong
surgical Intervention
Anterior/Posterior BPPV treamnt
Epley: Most common for AC/PC canalithiasis bppv
Semont: Most common for P/C & cupulolithiasis, A/C & P/C
Horizontal BPPV treatment
BBQ Roll: treats HC BPPV
- geotropic
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
Peripheral or central
Saccades
Central
Peripheral or central
Optokinetic (OKN)
Optokinetic nystagmus (OKN) abnormalities are generally of central origin.
