Chapter 35 - Eval of Vestibular Disorders Flashcards
Nystagmus characteristics in BPPV
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
Vestibular migraine
recurrent, severe, nauseating HA or recurrent auras
Vertigo spells vary, seconds to days
<50 commonly
Increased risk of BPPV, Meniere’s
Meniere’s Triad
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
Normal caloric response
Cold water –> nystagmus beat away from irrigated ear
COWS (cold opposite, warm same)
Ear with weakest response is damaged ear
How to test each: horizontal SCC, Anterior SCC, Vertical SCC, Utricle, Saccule
H SCC: horizontal head impulse test, caloric, rotational chair
A/P SCC: Vertical head impulse test, Dix Hallpike
Utricle: oVEMP
Saccule: cVEMP
Alexander’s Law
Peripheral nystagmus is faster, more apparent when patient gazes in direction of fast phase
Right-beating nystagmus worsens on right gaze
Most effective Tx for multisensory imbalance
Trekking poles initially
Rolling walker with handbrakes as dz progresses
Association between sleep apnea and balance
worsens migraine
associated with recurrent brief dizziness and inner ear dz (Meniere’s)
Ask patients with HA and vertigo about sleep apnea!
How to detect peripheral vestibular losses
If <50%, caloric testing
If more, impulse testing will likely detect it
How to do Dix Hallpike
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
Physical Exam of dizzy patient
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)
Nystagmus phases
Slow: vestibular system
Fast: corrective, saccade
Direction named by fast component
Dix Hallpike best at diagnosing what? What’s a positive test?
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
Signs of horizontal/anterior BPPV on Dix Hallpike
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
Nystagmus with Dix Hallpike other than BPPV
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
BPPV Sx
<1 min vertigo associated with head movement
Usually no hearing changes
Resolves spontaneously weeks/months
BPPV treatment
Shortens course
Epley maneuver 90% success rate
Half-somersault
If no response to Tx –> formal vestibular testing
Half Somersault
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
Most common cause of dizziness in kids, young adult
Migraine
Vertigo with Migraine
Vertigo seconds to days, may be with aura, HA or inbetween HAs
Migraine associated with Meniere’s
Treatment of migraine-dizziness
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.
Do triptans work for migraine vertigo?
Typically NO
Vestibular neuritis and viral labyrinthitis
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
Viruses that can totally destroy auditory and vestibular function in one ear
Mumps, measles, herpes zoster
Treatment of viral inner ear infections
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
Head thrust
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
Vestibular studies
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
Lab studies for long (1 hour) vertigo
CBC, ESR, ANA
Consider r/o HIV, syphilis, DM, clotting dz, lipid abnl
Diseases causing identical Sx as Meniere’s Dz
Syphilis, HIV, Autoimmune disease
Risks for Meniere’s
sleep apnea, migraine are associated
Also associated: smoking, DM, vasculitis, MI, stroke
When you get false negative with caloric testing
If only vertical canals or saccule/utricle are affected
Or if both ears have identical impairments
Which canal is tested with calorics?
Horizontal
cVEMP
Electrodes over SCM (cervical = c)
Detect EMG waves when saccule stimulated by loud sounds
What do delayed response and lowered threshold mean on cVMP in terms of pathology
Delayed: retrocochlear lesion
Threshold: SCC dehiscence
oVEMP
test stimulation of utricle by placing electrodes below the eyes
Sx of S SCC dehiscence
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
