Testing for vestibular function Flashcards
Components of a vestibular exam
- history and systems review: look for red flags
- subjective outcome measures: DHI, ABC
- vitals, strength, ROM, coordination, sensation, targeted tests
- screen cervical spine, VAT as appropriate
- oculomotor exam
- balance and gait: DGI/FGA
- positional testing
History and subjective portion
- common questions: symptoms, timing, triggers
- helps differentiate central vs peripheral
- red flags for central, cardiac
- if peripheral suspected, differential diagnosis is UVH, vs BVH vs distorted vs fluctuating
Identification of symptoms to determine diagnosis
- Dizziness: vague… could mean any of the below
- Vertigo: illusion of spinning
- Lightheadedness: faintness, presyncope
- Dysequilibirum: off balance
- Oscillopsia: perceived motion of stationary objects in visual environment
not as reliable
Characterization of symptoms to determine a dx
- Timing: episodic lasting seconds, minutes, hours, days, weeks OR continuous with exacerbation lasting how long?
- Triggers: spontaneous OR head motion or visual motion provoked?
- Hearing: involvement of auditory system, e.g. tinnitus, pressure, progressive or fluctuating hearing loss?
UVH vs BVH differential diagnosis
- Recent ear infection? vestibular neuritis, labyrinthitis
- Surgery near the ear? Vestibular schwannoma resection, labyrinthectomies
- Skew deviation of eye? UVH
- Use of antibiotics or h/o chemo? BVH
- Hearing loss? bilateral if BVH due to ototoxicity, unilateral if UVH due to labyrinthitits or surgery
- VOR disturbed? lesion side UVH, bilaterally in BVH
- Nystagmus? spontaneous nystagmus from UVH resolves in few days, none with BVH
- Vertigo? UVH 2˚ unequal signals
- Oscillopsia? BVH more likely
- LOB? more pronounced in BVH, only with faster motions toward lesioned side in UVH
Oculomotor exam
Observation for spontaneous nystagmus
- smooth pursuit: issue with smoothness = central
- gaze holding
- vergence: abnormal = >2-3 cm from face/not converging smoothly or at all = central lesion
- saccades: not accurate/timing = central lesion
direction changing nystagmus wiht the direction you are asking them to look at = central lesion/red flag
Peripheral nystagmus
peripheral nystagmus will always go the same direction and follow Alexander’s law (i.e. it will be accentuated if patient looks toward the fast phases, which are toward the more neurally active side).
VOR testing
- Head Impulse Test (HIT)
- Dynamic Visual Acuity (DVA)
- VOR cancellation
- Head-Shaking Induced Nystagmus (HSN)
head impulse test
- Tilt pt’s head forward 30º.
- Pt told to maintain visual fixation on your nose as you move pt’s head unpredictably through a small (30º) amplitude, high velocity head turn.
- If pt’s eyes fall off your nose, requiring a corrective saccade to refixate, the test is positive for that side.
Dynamic Visual acuity
- Pt reads lowest line possible on eye chart.
- PT moves pt’s head side to side at 2 Hz while pt repeats test.
- Normal result is < 3 lines decrement between static to dynamic visual acuity.
- Used to measure gaze stability in vestibular hypofunction and central disorders.
VOR cancellation
- Tilt pt’s head forward 30º.
- Move yourself and pt’s head in the same direction side to side 30º.
Pt should maintain fixation on your nose. - If pt unable to maintain fixation/ makes saccadic eye movements, test is positive for central lesion.
Tests performed with fixation blocked
- spontaneous nystagmus
- gaze-holding nystagmus
- head-shaking nystagmus
Head shaking nystagmus
- pts head is oscillated horizontally 20 x at2 Hz
- if this elicits nystagmus > 2 beats suggests vestibular asymmetry between the two horizonal canals
Balance and gait
- gait analysis including velocity
- TUG
- modified CTSIB
- DGI or FGA
- consider rhomberg, sharpened rhomberg, single leg stance
Positional testing
- includes: Dix-hallpike and Roll test
- better with fixation removed but can be performed in room light
- essential to diagnosis of BPPV
- each test is designed to place a specific canal in gravity dependent position
- differential dx depends on: provoking test, direction of nystagmus
- onset and duration of symptoms
Contraindication to Dix-hallpike test
- cervical stenosis, severe kyphoscoliosis
- limited cervical ROM
- ligamentous stability concern (down syndrome, paget’s disease, ankylosing spondylitis)
- severe RA
- cervical radiculopathies
- low back dysfunction
- SCI
- morbid obesity
type of nystagmus with
right posterior
- cupulolithiasis
- canalithiasis
- persistnet UBN + right torsion
- transient UNB + right torsion
type of nystagmus with left posterior
- cupulolithiasis
- canalithiasis
- persistent UBN + left torsion
- transient UBN + left torsion
Type of nystagmus of right anterior canal
- cupulolithiasis
- canalithiasis
- persistent DBN+right torsion
- transient DBN + right torsion
type of nystagmus with left anterior
- cupulolithiasis
- canalithiasis
- persistent DBN + left torsion
- transient DBN + left torsion
tyoe of nystagmus with left anterior
- cupulolithiasis
- canalithiasis
- persistent DBN + left torsion
- Transient DBN + left torsion
type of nystgmus with
horizontal
- cupulolithiasis
- canalithiasis
- persistent ageotrophic
- transient geotrophic
Diagnostic criteria for posterior canal BPPV
- patient reports episodes of vertigo with changes in head position AND
- each of the following are met
- vertigo + nystagmus occurs in Dix-hallpike test
- latency between test position and onset of vertigo + nystagmus
- provoked vertigo + nystagmus increase then resolve within 60 seconds
Treatment for BPPV
goals
- otoconia will be returned to utricle
- remission of vertigo with head movement
- improve balance and achieve independence with all ADLs involving head motion
treatment
- canalith repositioning maneuver appropriate to canal involed
Brandt-daroff exercises
- for suspected BPPV of unknown canal source
- if safe patient may try at home and report back to you which side provoked their symptoms
- recheck positional testing at follow up and perform indicated repositioning maneuver
- also used for habituation
treatment for UVH
goals
- improve gaze stability during head movement
- diminish sensititivy to head motion
- improve static and dynamic postural stability
- return to prior level of function/participation
- independence with HEP
treatment
- gaze stability
- postural stability
- habituation exercises
treament of BVH
goals
- improve gaze stability
- decrease gaze instability and oscillopsia
- improve static and dynamtic postural stability
- indpendent with HEP that inculdes walking program
treatment
- gaze stability
- postural stability exercises that enhance use of somatosensory and visual cues
gaze stability x 1 viewing
- patient focus eyes on near target while maintaing focus on target patient horizontally rotates head keeping target still
- perform 1-2 minutes 5x/day
- repeat for vertical
- ensure clear vision during motions
gaze stability x2
- patient focuses eyes on a near target
- while focus is maintained patient horizontally rotates head nad target in opposite direction s
- perfom 1-2 minutes 5x/day repeat for vertical head motions
- ensure clear vision during motions
gaze stability: 2 target VOR
- place 2 targets X and Z on the wall 2 feet apart horizontally
- patient looks at X then moves head toward X
- patient looks at Z moves toward Z
- always keep targets clearly in focus
- partacice 1-3 minutes resting PRN
- repeat for vertical head movements
- progress to eye sna dhead moving simultaneously
Gaze stability: remembered targets
- patient looks at target directly ahead on wall
- patient closes eyes and turns head slightly imagining staying on arget then opens eyes to see if still on target
- return to center then repeat in opposite direction
- practice up to 3 minutes
- repeat for vertical movements
Habituation
- used to treat motion-provoked dizziness in UVH
- habituation is a reduction in response to repeated preformance of a movement
- choose up to 4 provoking movements
- patient repeats these movemetns 3-5 x 2-3 x/day
- resting between movements until symptoms stop
- movements should provoke mild to moderate symptoms
- incorporate into ADLs as able
postural stability
- consider which of patients impairments may be rehabed and which require compensation/substitution
- alter visual and somatosensory cues as appropriate to the patient
- head movement and motor learning concepts should be incorporated into balance training
- update program regularly to add progressive challenges
treatment of central vestibular disorders
goals
- enhance decision making regarding fall prevention and saftey
- select appropriate compensatory strategies for gaze stability
- prevent deconditioning via independence with HEP including walking program
treatment
- gaze stability
- habitutaiton
- gait and balance
- incorporate somatosensory, visual and vestibular inputs