Chpt 4: Vestibular System

Front 1

Dsecribe the shape of type I vs type II hair cells.

Back 1

Type I: chalice-shaped
Type II: boutonniere-shaped

Front 2

What happens to resting discharge rate of hair cells when the kinocilium is deflected away from the stereocilia?

Back 2

Increased

Front 3

In the lateral SCC, does ampullopetal endolymphatic flow cause displacement of the kinocilium toward or away from the stereocilia.

Back 3

Away, toward the utricle, resulting in INCREASE in discharge rate.

Front 4

In the superior and posterior SCCs, what is the result of ampullopetal endolymphatic flow?

Back 4

Ampullopetal flow causes a DECREASE in the basal firing rate.

Front 5

Describe first, second, and third-degree nystamus.

Back 5

First degree: nystagmus beats in the direction of the gaze.
Second degree: nystamus is present on straight gaze and in direction of the fast component of nystagmus
Third degree: nystagmus present in all three directions of gaze.

Front 6

Which phase of nystagmus is the direction of flow of the endolymph?

Back 6

slow phase

Front 7

Which phase of nystagmus determines its direction?

Back 7

fast phase

Front 8

Can labyrinthine spontaneous nystagmus be supressed by fixation?

Back 8

YES

Front 9

Nystagmus beats in the direction of less or greater vestibular function?

Back 9

greater function

Front 10

What are the characteristics of positional vertigo of the benign paroxysmal type?

Back 10

1) rotary nystagmus
2) clockwise nystagmus with left ear down
3) latency of 5-15sec
4) fatiguability
5) upright position may lead to nystagmus in the opposite direction
6) repeat tests without rest results in no nystagmus

Front 11

For the fistula test, which direction will the nystagmus be if positive presssure is used to stimulate the ear?

Back 11

nystagmus toward the stimulated ear

Front 12

If the right ear is instilled with cold liquid, which way will the nystagmus be?

Back 12

toward the left ear

Front 13

In an ENG, what is considered to be the most accurate predictor of the etiology of disease?

Back 13

velocity of the slow phase

Front 14

What does it mean if one ear is hypoactive compared with the other?

Back 14

Stimulation of that ear with calorics (both cold and warm)does not result in as long a duration of nystagmus as stimulation of the other ear

Front 15

What is directional preponderance?

Back 15

Induced nystagmus in one direction lasts longer than induced nystagmus in the other direction

Front 16

If caloric-induced nystagmus cannot be suppressed by ocular fixation, what kind of lesions is suggested?

Back 16

central

Front 17

What are the parameters measured in harmonic acceleration testing?

Back 17

1) the gain
2) the phase
3) symmetry

Front 18

Define gain in the setting of rotational testing.

Back 18

the ratio of the peak amplitude of the chair speed compared to eye speed

Front 19

Define phase in the setting of rotational testing.

Back 19

relationship of the peak response of the slow component eye movement compared to the peak velocity of the chair

Front 20

Abnormal phase leads at low frequencies suggests what kind of disorder?

Back 20

peripheral vestibular disorder

Front 21

Abnormal phase leads for all frequencies are indicative of what kind of lesions?

Back 21

central lesions

Front 22

What does dynamic posturography assess?

Back 22

balance capabilities in challenging visual and support surface environments

Front 23

What is the role for posturography?

Back 23

in rehabilitative management of patients

Front 24

What percent of CPA tumors do acoustic neuromas comprise?

Back 24

80%

Front 25

What is the first modality affected by pressure on CN V?

Back 25

altered corneal sensation

Front 26

Define internuclear opthalmoplegia.

Back 26

disturbance of the lateral movements of the eyes characterized by the paralysis of the internal recturs on one side and weakness of the external rectus on the other

Front 27

Where is the pathology in INO?

Back 27

in the medial longitudinal fasciculus

Front 28

What should be considered in cases of bilateral INO?

Back 28

multiple sclerosis

Front 29

What are the four symptoms of Meniere's disease?

Back 29

1) fluctuating SNHL
2) fluctuating tinnitus
3) fluctuating fullness
4) episodic vertigo

Front 30

How long do vertigo attacks usually last with Meniere's disease?

Back 30

30 minutes - 2 hours

Front 31

What percentage of patient have involvement of only one ear in MD?

Back 31

85%

Front 32

In the natural history of MD, what is the rate of natural remission?

Back 32

60%

Front 33

What is Lermoyez Syndrome?

Back 33

increasing tinnitus, hearing loss, and aural fullness that is relieved after an episodic attack of vertigo

Front 34

What are the medical therapies for MD?

Back 34

1) vestibular suppresants
2) vasodilators
3) diuretics

Front 35

What are surgical therapies for MD?

Back 35

1) gentamicin of streptomycin application to the inner ear
2) vestibular nerve section
3) labyrinthectomy
4) endolymphatic sac surgery

Front 36

What is the glycerol test?

Back 36

Give glycerol in oral dose of 1.2ml/kg with equal amount of phsiologic saline. Within 1 hours, patients may sense an improvement in MD symptoms. Maxiumum effects occur within 2-3 hours.

Front 37

What is Charcot triad - found in patients with MS?

Back 37

1) nystagmus
2) scanning speech
3) intention tremor

Front 38

What does oscillopsia suggest?

Back 38

bilateral absent vestibular function

Front 39

When can otosclerosis be associated with vertigo?

Back 39

1) fixed footplate can change fluid dynamics of the inner ear
2) post-stapedectomy perilymphatic fistula
3) otosclerotic focus around the labyrinth with elevated blood fat and glucose
4) otosclerotic focus may grow through the vestibular nerve

Front 40

What are common manifestations of syphilis?

Back 40

1) significant hearing loss
2) bilateral absent caloric function
3) interstitial keratitis
4) positive Hennebert's sign - postivie fistula test without any demonstrable fistula
5) Tullio's phenonomenon

Front 41

What is the treatment for syphilis?

Back 41

10 million units of pcn daily for 10 days, steroids

Front 42

What are the findings with a labyrinthine concussion?

Back 42

1) high frequency hearing loss
2) mild unsteadiness, particularly with change of head position
3) ENG shows spontaneous or positional nystagmus and a reduced vestibular response

Front 43

What is the cause of labyrinthine apoplexy?

Back 43

thrombosis of the internal auditory artery

Front 44

What are the symptoms of labyrinthine apoplexy?

Back 44

acute vertigo with nausea and vomiting
hearing loss and tinnitus may also occur

Front 45

What are the findings in Wallenberg Syndrome?

Back 45

1) vertigo, nausea, vomiting, nystagmus
2) ataxia, falling toward the side affected
3) loss of pain and temperature sensations on the ipsilateral face and contralateral body
4) dysphagia with ipsilateral palate and VC paralysis
5) ipsilateral Horner's syndrome

Front 46

What is the etiology of Wallenberg syndrome?

Back 46

infarction of the medulla supplied by the posterior inferior cerebellar artery

Front 47

What are clinical signs of vertebrobasilar insufficiency?

Back 47

drop attacks without loss of consciousness and precipitated by neck motion

Front 48

What is the pathophysiology of cervical vertigo?

Back 48

cervical spondylosis causes irritation of the vertebral sympathetic plexus leading to contraction of the vertebral and basilar arteries.

Front 49

Differential diagnosis of the dizzy patient.

Back 49

acoustic neuroma
prebystasis
cogan's syndrome
BPPV
INO
intracranial tumor
Meniere's Disease
metabolic vertigo
Multiple Sclerosis
Oscillopsia
Otitis media
Otosclerosis
Ototoxic drugs
perilymph fistula
posttraumatic vertigo
syphilis
temporal bone fracture
vascular insufficiency
vestibular neuronitis
vertinous epilepsy
vertigo due to whiplash
vertigo with migraine

Front 50

Vertigo is the presenting symptoms in what percentage of MS patients?

Back 50

7-10%