Vestibular

Question 1

What are parts of vestibular anatomy?

Answer 1

Peripheral sensory apparatus: provides sensory input about angular and linear acceleration, orients head with respect to gravity
Central processing system: somatosensory and visual cues, cerebellum, reticular formation, cortex
Motor output system: generates compensatory eye movements for gaze stability, body movements for postural stability with locomotion

Question 2

What does the peripheral sensory apparatus contain?

Answer 2

Membranous labyrinth: contains 5 sensory organs (3 semicircular canals), 2 otolith organs (utricle and saccule), motions sensors (hair cells), endolymph

Question 3

what is physiology of semicircular canals?

Answer 3

Each canal plane is perpendicular to other canal planes.
Planes of the semicircular canals between labyrinths conform closely to each other forming 3 coplanar pairs
Coplanar pairing of canals is associated with push-pull change in quantity of canal output.
Planes of canals are close to planes of extra ocular muscles
Info is used to stabilize vision

Question 4

What is VOR gain?

Answer 4

Head moves in one direction, eyes move in opposite direction with equal velocity.
Regulated by semicircular canals
Vestibular system responsible for maintaining gaze stability at greater than 60 degrees per second
Smooth pursuit responsible for maintaining gaze stability at less than 60 degrees per second (CNS)

Question 5

What is cause of nystagmus? What does it indicate? How is it named?

Answer 5

Cause is differences between sides in tonic firing rate within the vestibular nuclei
Indicates that one vestibular system is more active than the other.
Fast beat always toward more active side
If fast beating right, right side is hyper active or left side is hypoactive
Resolves due to CNS adaption or head tilting

Question 6

What are causes of dizziness?

Answer 6

Peripheral vestibular disorders: BPPV, meneires, neuritis, perilymphatic fistula
Non vestibular causes: dis use equilibrium
Orthostatic hypotension: SBP drops by at least 20 mmHg within 3 minutes of standing and patient is symptomatic
Transient ischemic attacks from vertebra-basilar ischemia
Panic attacks: reaches crescendo in 10 minutes associated with dizziness
Migraines: spells last 4-60 minutes with or w/o HA

Question 7

What is differential diagnosis for central vs peripheral vestibular disorders? (vertigo, nystagmus, balance, smooth pursuit, saccades, hearing, compensation)

Answer 7

Vertigo: more common in peripheral
Nystagmus: jerk with peripheral; vertical and pendular with central
Balance: more affected in central
Smooth pursuit, saccades: abnormal in central
Hearing: hearing loss, tinnitus, fullness in ears in peripheral
Compensation: quick in peripheral, slow in central

Question 8

What is summary of examination of vestibular problems across the ICF?

Answer 8

Body function and structure: oculomotor tets, dix-hallpike, mCTSIB
Activity: DGI, FGA
Participation: dizziness handicap inventory, activities specific balance confidence scale, falls efficacy

Question 9

What is the dizziness handicap inventory?

Answer 9

0-100, 0= no dizziness, 2=sometimes, 4= yes
higher score indicates greater handicap
0-14: no activity limitation
16-26: mild limitation
28-44: moderate limitation
more than 46: severe
People with BPPV- greater handicap
DHI more than 60 associated with impaired functional mobility and increased fall risk
Useful to establish subjective improvement

Question 10

What is the activities specific balance confidence scale?

Answer 10

Confidence level performing various tasks of daily living (rate 0-100%)
Correlates with physical functioning; less than 50 is low level, 50-80 is moderate, more than 80 is high level of functioning
ABC score of less than 67 indicates increased risk for falls

Question 11

What are parts of physical exam for vestibular disorders?

Answer 11

Oculomotor function: saccades, smooth pursuit, visual acuity static and dynamic
Nystagmus: spontaneous, gaze evoked, head thrust, head shake
Sensory testing
ROM: cervical spine
Motor testing
Vertebro-basilar artery testing
Positional testing: dix-hallpike, roll test
Balance testing

Question 12

What are the positional tests for vestibular disorders?

Answer 12

Roll test: test for horizontal SCC, positive on both sides
Dix Hallpike: provocative position will produce torsional nystagmus, nystagmus of 1-5 sec latency, nystagmus of brief duration 5-30 sec, reversal of nystagmus direction on return to upright position, response is fatigueable
Motion sensitivity quotient: 16 positions tested, 0-10 is mild, 11-30 is moderate, 30-100 is severe

Question 13

What are static balance examination tests?

Answer 13

Four square step test, berg balance, functional reach, modified CTSIB, BEST test/mini BEST, romberg sharpened Romberg, single leg stance

Question 14

What are dynamic balance examination tests?

Answer 14

DGI, FGA, TUG, dual task TUG, 10 meter walk, five times sit to stand

Question 15

What is BPPV?

Answer 15

Single most common cause of dizziness encountered in clinic.
50% of people over age of 65 have it
Most common cause in people under 50 is TBI, and over 50 is vestibular degeneration

Question 16

What is patient presentation for BPPV?

Answer 16

Brief episodes of vertigo associated with changes in head position relative to gravity: lying down, getting up, rolling over, bending over, looking up
Imbalance in more than 50% of patients, trouble walking in 48%, nausea in 35%

Question 17

What is technique for dix-hallpike test?

Answer 17

45 degree cervical rotation, sit to supine with 20 degree cervical extension, look for nystagmus and symptoms of vertigo

Question 18

What does a typical nystagmus look like?

Answer 18

Latency: 1-5 seconds
Direction: typically mixed up beating, torsional nystagmus
Duration: generally less than 2 min
Fatigues

All we need to know is direction to tell us what canal is involved and duration which will tell us what type of BPPB it is

Question 19

What are exercises to give patients to help with BPPV?

Answer 19

Brandt-Daroff
5 reps 2/day
Hold each position for 30 sec

Question 20

What is an example of unilateral vestibular hypofunction?

Answer 20

Vestibular neuritis: acute, unilateral, may have viral etiology, prolonged severe rotational vertigo with spontaneous nystagmus, imbalance, nausea, hearing is usually spared

Question 21

What are evaluation results in acute UVL?

Answer 21

Spontaneous and gaze= evoked nystagmus in light and dark, HSN
VOR abnormal both slow and thrust
Romberg often positive
Sharpened Romberg unable
Single leg stance unable
CTSIB foam, EC unable
Gait: wide based, slow cadence, decreased rotation
Turn head while walking unable

Question 22

What are evaluation results in compensated UVL?

Answer 22

Spontaneous in dark, may have HSN
VOR abnormal with rapid thrust toward side of lesion
Romberg negative
Sharpened Romberg- normal with eyes open, unable with EC
SLS- normal
CATSIB on foam, EC- normal
Gait is normal
Turn head- normal, slow cadence

Question 23

What are vestibular rehab goals for unilateral lesion?

Answer 23

Improve patient’s functional balance especially during ambulation
Improve patient’s ability to see clearly during head movement
Improve the overall general physical condition and activity level
Reduce patient’s social isolation
Decrease patient’s disequilibrium and dizziness with movement

Question 24

What are guidelines for developing vestibular exercises?

Answer 24

Best stimulus is to induce adaptation is one producing an error signal.
Adaptation takes time
Adaptation of vestibulo-ocular system is context specific
Adaptation is affected by voluntary motor control
Patient’s should work at the limit of their ability

Question 25

What is functional carry over of gaze stability? Does is work?

Answer 25

Carry over: turning head during conversation, ride in a car and identify street signs, safely cross a busy street
70% show increase in dynamic visual acuity, 70-75% show decrease fall risk

Question 26

What are habituation exercises?

Answer 26

Repeated exposure to a provocative stimulus will result in reduction in pathological response.
Use motion sensitivity as basis for developing program.
Up to 4 movements are chosen, done 2-3 times a day, head movements encouraged
Should produce mild to moderate symptoms
Rest between movements for symptoms to stop
May take up to 4 weeks for symptoms to decrease

Question 27

What should program include for static postural stability?

Answer 27

Decrease somatosensory and visual inputs.
Program should include: various standing positions with feet apart and together, head turns with standing and ambulation, eyes open and close, on firm and foam surfaces, walking backwards, turning, on ramps and curbs, bouncing on swiss ball or trampoline

Question 28

What are ideas for dynamic stability?

Answer 28

Walking outdoors on sidewalks, in grass, in grocery store with head turns, in the mall with and against flow of traffic