Chapter 35 - Eval of Vestibular Disorders

Question 1

Nystagmus characteristics in BPPV

Answer 1

torsional, up-beating
Triggered by Dix-Hall with AFFECTED EAR DOWN
paroxysmal, build to peak then disappears over seconds
Latency of several seconds
Fatigue with repeated DH maneuvers

Question 2

Vestibular migraine

Answer 2

recurrent, severe, nauseating HA or recurrent auras
Vertigo spells vary, seconds to days
<50 commonly
Increased risk of BPPV, Meniere’s

Question 3

Meniere’s Triad

Answer 3

Fluctuating HL, worse during vertigo
Aural fullness/pressure
Vertigo hours in duration (30 min-several hr), severe, vomit
Fluctuating tinnitus, louder during vertigo, may roar
Relapsing remitting, chronically progressive, permanent hearing loss

Question 4

Normal caloric response

Answer 4

Cold water –> nystagmus beat away from irrigated ear
COWS (cold opposite, warm same)
Ear with weakest response is damaged ear

Question 5

How to test each: horizontal SCC, Anterior SCC, Vertical SCC, Utricle, Saccule

Answer 5

H SCC: horizontal head impulse test, caloric, rotational chair
A/P SCC: Vertical head impulse test, Dix Hallpike
Utricle: oVEMP
Saccule: cVEMP

Question 6

Alexander’s Law

Answer 6

Peripheral nystagmus is faster, more apparent when patient gazes in direction of fast phase
Right-beating nystagmus worsens on right gaze

Question 7

Most effective Tx for multisensory imbalance

Answer 7

Trekking poles initially

Rolling walker with handbrakes as dz progresses

Question 8

Association between sleep apnea and balance

Answer 8

worsens migraine
associated with recurrent brief dizziness and inner ear dz (Meniere’s)
Ask patients with HA and vertigo about sleep apnea!

Question 9

How to detect peripheral vestibular losses

Answer 9

If <50%, caloric testing

If more, impulse testing will likely detect it

Question 10

How to do Dix Hallpike

Answer 10

Turn head 45 deg to side, rapidly go supine, observe 15-30 sec. Support head.
If elderly, frail or neck problems, lower head onto table rather than letting it go over the edge

Question 11

Physical Exam of dizzy patient

Answer 11

Ear, hearing
CN
Cerebellar coordination, gait, balance
Carotid bruits
Sensory lesions or ROM restrictions of legs/feet
Dix Hallpike (BPPV), Head Impulse (for vestibular loss)

Question 12

Nystagmus phases

Answer 12

Slow: vestibular system
Fast: corrective, saccade
Direction named by fast component

Question 13

Dix Hallpike best at diagnosing what? What’s a positive test?

Answer 13

Posterior canal BPPV
rotatory/vert nystagmus, sensation of vertigo several seconds after head-hanging position
Nystagmus fades after <1 minute, reverses direction upon sitting, fatigues with repeated testing

Question 14

Signs of horizontal/anterior BPPV on Dix Hallpike

Answer 14

Hor: Violent, horizontal nystagmus, last up to 1 min, vomiting
Ant: fine, downbeating nystagmus, may persist a few minutes. More likely if recent posterior canal treatment

Question 15

Nystagmus with Dix Hallpike other than BPPV

Answer 15

Yes, other disorders can cause nystagmus with DH
But….
Nystagmus will not fade away while hanging head, will not fatigue with repeated testing, does not require quick movement to bring it out

Question 16

BPPV Sx

Answer 16

<1 min vertigo associated with head movement
Usually no hearing changes
Resolves spontaneously weeks/months

Question 17

BPPV treatment

Answer 17

Shortens course
Epley maneuver 90% success rate
Half-somersault
If no response to Tx –> formal vestibular testing

Question 18

Half Somersault

Answer 18

Kneel down, hands on floor
Head rapidly up towards celing
Head upside down on floor
Rotate head to face elbow same side as bad ear
Head up to back level, still facing side
Briskly raise head fully upright
Pause 30 seconds with each move
15 minutes between maneuvers

Question 19

Most common cause of dizziness in kids, young adult

Answer 19

Migraine

Question 20

Vertigo with Migraine

Answer 20

Vertigo seconds to days, may be with aura, HA or inbetween HAs
Migraine associated with Meniere’s

Question 21

Treatment of migraine-dizziness

Answer 21

If once every few weeks or less, use meclizine or promethazine
If more often, prophylaxis with TCA, BB, CCB, topamax, divalproex, acetazolamide. Try for 1 mo before a new one.

Question 22

Do triptans work for migraine vertigo?

Answer 22

Typically NO

Question 23

Vestibular neuritis and viral labyrinthitis

Answer 23

Both are unilateral vestibulopathy, preceded by viral illness
Sudden onset of vertigo within hours to days of virus
Rapid peak, gradual decline over days to weeks
If hearing also affected, called viral labryinthitis, otherwise, called vestibular neuronitis
Mild light-headedness with head movement may persist for months

Question 24

Viruses that can totally destroy auditory and vestibular function in one ear

Answer 24

Mumps, measles, herpes zoster

Question 25

Treatment of viral inner ear infections

Answer 25

steroids initiate within first few days
meclizine, diazepam, promethazine for vomiting but just for a week, to not interfere with compensation
May do vestibular rehab if still sx after a week

Question 26

Head thrust

Answer 26

Tell them to stare at your eyes
Rapidly turn head to good side, their eyes stay at yours
When head turned toward rapidly abnormal inner ear, eyes move with head and lose fixation, then refixation saccade if peripheral vestibular loss
Called Doll’s eye when testing on comatose patient

Question 27

Vestibular studies

Answer 27

VNG for vertigo other than BPPV
If asymmetric or localizing VNG or neuro test, then also do MRI with gad for IAC, posterior fossa
CT w/o contrast if suspected congenital T-bone issue

Question 28

Lab studies for long (1 hour) vertigo

Answer 28

CBC, ESR, ANA

Consider r/o HIV, syphilis, DM, clotting dz, lipid abnl

Question 29

Diseases causing identical Sx as Meniere’s Dz

Answer 29

Syphilis, HIV, Autoimmune disease

Question 30

Risks for Meniere’s

Answer 30

sleep apnea, migraine are associated

Also associated: smoking, DM, vasculitis, MI, stroke

Question 31

When you get false negative with caloric testing

Answer 31

If only vertical canals or saccule/utricle are affected

Or if both ears have identical impairments

Question 32

Which canal is tested with calorics?

Answer 32

Horizontal

Question 33

cVEMP

Answer 33

Electrodes over SCM (cervical = c)

Detect EMG waves when saccule stimulated by loud sounds

Question 34

What do delayed response and lowered threshold mean on cVMP in terms of pathology

Answer 34

Delayed: retrocochlear lesion
Threshold: SCC dehiscence

Question 35

oVEMP

Answer 35

test stimulation of utricle by placing electrodes below the eyes

Question 36

Sx of S SCC dehiscence

Answer 36

torsional vertigo, trigger by loud sounds, blowing nose, sneezing, straining
hear internal bodily sounds (pulse, chew) magnified in one ear
Brief tinnitus when eyes move side to side