Vestibular Lecture part 2 Flashcards
Episodic vestibular conditions
– Benign Paroxysmal Positional Vertigo (BPPV)
– Vestibular migraine
– Meniere’s Disease
– Anxiety (? Situational)
Sudden/acute onset vestibular conditions
– Vestibular neuritis/labyrinthitis
– Vascular (TIA, CVA)
Persistent/Chronic vestibular conditions
– Chronic concussion/mTBI
– Persistent Postural-Perceptual Dizziness (PPPD)
physical therapy assessment of vestibular system
- subjective history
- functional mobility assess
- oculomotor exam
subjective description of “dizziness”
- onset
- quality (lightheaded, spinning, imbalance)
- severity (verbal rating sale or visual analog scale)
- frequency
- duration
blurred vision can be a result of what two things?
- VOR impairment or visual activity
What is double vision typically a sign of?
central involvement
hearing impairment
- Often accompanies peripheral vestibular involvement
- Patients are not always aware of changes in hearing unless they are sudden and significant
- Audiogram can identify impairment
Good questionnaires to use
- dizziness handicap inventory
- activity specific balance confidence scale
- visual vertigo analog scale
Modified Motion Sensitivity test
- Systematically monitor subjective dizziness and
presence of nystagmus to assess sensitivity to
motion - Used as a tool to monitor progress in subjective
dizziness over time - Items on test that cause dizziness can be used as starting points for treatment
- 10 items, all movements are in standing
- monitor symptom intensity and duration
what 10 items are on the modified motion sensitivity test
– Horizontal, vertical, diagonal head turns
– Standing trunk bends (reach to floor)
– Turns- trunk rotation and 360 degree
– VOR cancellation- visual motion
Balance assessment
– Romberg
– mCTSIB
– Berg Balance Scale
– Weight shifting
– Balance reactions (stepping strategy)
oculomotor exam provides information on:
ocular alignment and motility
central oculomotor control
– Vergence
– Smooth Pursuit
– Saccades
– VOR Suppression/cancellation
Vestibular Function in the Oculomotor exam
– Presence of Nystagmus
* Spontaneous or Gaze-evoked
– Head Impulse/Thrust
– Clinical DVA test
– Head Shaking Nystagmus test
Ocular ROM
- Ensure that patient’s eyes are moving
conjugately and in all directions - Full ROM
Near point of convergence
- Slowly bring discrete target in toward bridge of nose
- Have pt. identify when object blurs, then doubles
- Measure distance for target doubling
- < 6 cm = WNL
- Note any symptom provocation
- Often caused by fatigue
- Use reading glasses if pt. needs them for near vision
convergence
- Gold standard is performed by observing retinal fusion via otoscope
- Patients may have subjective blurring or diplopia that is not consistent with retinal fusion
smooth pursuit deficit is indicative of what?
a central deficit
smooth pursuit
- Patient follows pen with head still in vertical and horizontal directions
- Look for quality of movement or “jumping –> Documented as “corrective saccades”or
“saccadic intrusions” - Degrades with inattention, age, sedatives and speed
what structures are smooth pursuit primarily a function of?
parieto-occipital cortex, pons and cerebellum
VOR Cancellation issues is typically indicative of what?
Central deficit
VOR Cancellation
- Sit in front of pt. and instruct patient to focus on your nose
- Rotate patient’s head left/right as you move with
him/her - Eyes and head stay together
- Look for saccadic movements, which are a sign of an inability to fixate
- Even if normal, may have increased symptoms due to visual motion
What should you do before performing a Head Thrust (AKA Head Impulse Test)
check cervical ROM and tolerance to quick motion
Head Thrust Procedure
- Sit in front of pt, instruct them to relax neck
and focus on your nose - Thrust head rapidly over a small amplitude
- Look for pt ability to stay focused on your
nose - Look for corrective saccades to catch up to your nose after their gaze slipped off
- Note head thrust direction when it occurs
- Too fast to involve the cerebellum so primarily
VOR test
What is a good differentiator between peripheral and central lesions?
head thrust
a positive head thrust indicates what?
a peripheral sign
a successfully performed head thrust test should be…
- FAST
- Unpredictable
- Small amplitude
Dynamic Visual Acuity Test
- Have pt. sit at appropriate distance from chart and read the lowest line possible
- Stand behind pt and turn head at 2 Hz while
he/she reads lowest line possible - Use Metronome to ensure correct speed
- Drive pt. to make at least one mistake- don’t let them quit early
- A degradation of 3 or more lines indicates an impaired VOR
does dynamic visual acuity test indicate a central or peripheral deficit?
can be either
DVA differential diagnosis:
– Central- concussion, migraine, central vestibular
– UVH or BVH
– Low tolerance to movement due to highly symptomatic
– Anxiety
– Decreased effort
What is good for test-retest to determine if a pt is progressing, or has compensated for a hypo function?
DVA
what is the primary intervention strategy for a positive DVA
VOR x 1
Gaze Shifting
When checking spontaneous nystagmus, what will a patient with a peripheral lesion present with?
- spontaneous nystagmus only in the acute phase
- will be suppressed by smooth pursuit
When checking spontaneous nystagmus, what will a patient with a central lesion present with?
- may have nystagmus in a variety of directions in acute and chronic phases
- will see corrective saccades during smooth pursuits
how is gaze evoked nystagmus test performed
- with the fancy goggles
- ask pt to look to the left, right, up and down,
approximately 30 degrees, for at least 15 sec.
each - observe for nystagmus and direction
during gaze evoked nystagmus test, what finding would be indicative of a central sign?
Nystagmus in the direction of gaze or that
changes directions
during gaze evoked nystagmus test, what finding would be indicative of a peripheral sign?
Nystagmus that is in the same direction (left
beating w/left gaze and upward gaze, none
with right gaze)
How is head shaking nystagmus test performed?
- Ask pt. to close eyes and turn head 30-45º
bilaterally 20 repetitions at speed sufficient to
stimulate the vestibular system - Before stopping, ask pt. to open eyes
- Observe any nystagmus
- More than 3 beats is considered abnormal
a positive head shaking nystagmus test is indicative of what?
non-specific peripheral sign
What are your intervention options
- habituation: motion sensitivity
- sensory organization
- gaze stabilization
- habituation: visual motion intolerance
what is the primary recovery strategy to improve function of the VOR?
gaze stabilization
what should you use gaze stabilization?
-if DNA is impaired
- pt may or may not have a positive head thrust test
- best with intact CNS
what 2 processes does gaze stabilization use?
- change in gain of VOR using adaptation
- use of compensatory saccades to supplement VOR
gaze stabilization flow chart
using exercise, create a controlled retinal slip with head movement –> results in creation of an error signal –> brain makes a long term change in response to the error signal –> retinal slip decreases and there is better vision and less dizziness
principles of VOR exercises
- Target at least 3-5 ft away
- Horizontal and vertical directions
- Goal is 1 minute each direction
- 3-5x/day
- Move head as fast as able maintaining a stable target
- TARGET MUST STAY CLEAR
Gaze shifting at slower velocities:
combined smooth pursuit and saccades
gaze shifting at faster velocities:
combines saccades and VOR
what is the primary mechanism for visual scanning of environment
gaze shifts
when should you use gaze shift interventions
when VOR x 1 is too difficult or symptoms are too elevated
what should gaze shifts be used in combination with?
gaze stabilization training
how to perform gaze shift intervention:
Two targets: Start with eyes and head on one target, move eyes to next target but keep head still, then move head to the next target once eyes are stable –> works on eye/head coordinated movement
how to progress gaze shifts
process to eyes and head moving together to each target
CPG recommendations for peripheral vestibular hypofunction
– 12 min of gaze stability exercises per day
– Can be a combo of gaze shifting, VOR x 1, etc.
– No evidence for smooth pursuit or saccade exs
what is the goal of habituation
Used to relieve motion induced dizziness or vision motion intolerance
How does habituation decrease symptoms?
by systematically provoking symptoms through repeated exposure to specific provoking motor or visual task
2 important things to remember with habituation:
- PACING: only need to drive symptoms up enough to induce moderate symptoms to get results
- PATIENT EDUCATION is a MUST
what in your assessment leads you to do habituation?
- Modified Motion Sensitivity Test
– Motion sensitivity- patient’s own motion
– Visual motion intolerance- motion in the
environment, even when pt. is still - Patient report of dizziness with specific exacerbating conditions
habituation exercise design
- identify provoking movement OR visual motion task
- performs movement or is exposed to visual motion –> symptoms go up no more than 5/10 –> rest and allow symptoms to return to baseline
habituation: motion sensitivity interventions
– Head turns in standing/gait
– Turning quickly
– Bending to pick up objects
habituation: visual motion intolerance interventions
Optokinetic Stimulation:
– VOR cancellation
– Ball toss
– Reading while walking (visual flow)
– Busy background
– Twirling Umbrellas
Habituation summary
– Habituation is used a primary intervention
– Use repeated exposure to provoking stimulus
– Progress as patient tolerates
– More is not always better!
– Patient must understand why you are provoking their symptoms and the goal of intervention
Sensory Re-weighting training things to remember:
- Identify patients that are visually dependent
– Developed ineffective compensatory strategies
– Postural instability or increased symptoms in complex visual environments - Important for patients to be proficient at
somatosensory tasks prior to progression to vestibular re-weighting
– Static and dynamic, with head movement
Sensory Re-weighting Training to enhance vestibular feedback:
disadvantage both somatosensory and visual feedback
Balance interventions for sensory re-weighting
- Important to challenge balance
without UE support (Should include only postural support used in function) - Not too much challenge- too large of an “error
signal” and the CNS will not induce change - Important to challenge static and dynamic systems
- Reactive and anticipatory postural responses
Sensory Re-Weighting Summary
– Important to identify those that are visually dependent
– Proficient at somatosensory before training vestibular feedback
– Don’t use UE support during balance tasks
– Static and dynamic training- include variety
Static Compensation
Initial spontaneous nystagmus resolves after
unilateral peripheral loss with or without any
visual input
Dynamic Compensation
VOR won’t recover without an error signal created
by visual input, to drive a change in the system
what is “compensation” used to define?
when someone has achieved adaptation- VOR is working due to changes in the central system to accommodate for peripheral loss
**it is not used to describe substitution
Medications
- Meclazine (AKA Dramamine)
– Over the counter
– Vestibular suppressant
Patient education - pacing
- Symptoms no higher than 5/10
- Rest between activities
- After therapy exercises, symptoms should
not last longer than 15-30 minutes
Intervention for Chronic Dizziness/PPPD
- Validate pt’s experience and symptoms
- objectively describe pathophysiology and path to recovery
- discourage hypervigilence and catastrophic thinking
- sensory re-weighting
- posture control and balance confidence- “grounding”
- core stabilization
- fitness/endurance
- participation in community activities, work, volunteering as tolerated
- habituation
- lower autonomic nervous system reactivity
problem list
- Gaze instability
- Motion sensitivity
- Visual motion intolerance
- Postural stability impairment
– Gait
– Static/dynamic balance - Musculoskeletal impairment
- Exercise intolerance
gaze instability and dizziness - intervention
gaze stabilization
motion sensitivity - intervention
habituation
visual motion intolerance - intervention
Optokinetic, habituation
postural imbalance - intervention
- sensory organization
- reactive and APA control
complete bilateral loss - intervention
- gaze stabilization
- sensory organization (visual and somatosensory)
- postural control
prognosis
- Age does not matter
- Migraine makes recovery harder, even if not Migraine-related vestibulopathy
- Good recovery for BPPV
- Central Vestibular disorders get better, but take
longer and have more guarded outcomes - Bilateral Vestibular disorders have a similar result
factors affecting PT recovery
- sleep
- emotional issues
- headache/migraine
- social support, social roles
