oto vestibular and balance disorders

Question 1

What is the differential diagnosis of Ménière

disease.

Answer 1

Perilymphatic fistula, vestibular migraine, Cogan syndrome, autoimmune hearing loss, syphilis, mumps, Mondini mal-
formation

Question 2

What percentage of patients with Ménière disease

will develop bilateral involvement?

Answer 2

Approximately 30%

Question 3

What medical treatments are most commonly
used for symptomatic treatment of active Ménière
disease?

Answer 3

● Vestibular suppressants (e.g., benzodiazepines promethazine)
● Rest
● Potentially corticosteroids

Question 4

What are the two most commonly used surgical

approaches for vestibular neurectomy?

Answer 4

● Middle fossa or the retrosigmoid approach
● Retrolabyrinthine and transmeatal approaches have also
been used.

Question 5

How does the efficacy of endolymphatic shunt placement compare with endolymphatic sac decompression for treatment of Ménière disease?

Answer 5

No trials have clearly demonstrated superior results in one

treatment over the other.

Question 6

Review the clinical presentation of Ménière

disease.

Answer 6

Low-frequency sensorineural hearing loss (SNHL, fluctuating and progressive), roaring tinnitus, aural fullness, and episodic vertigo generally lasting for hours

Question 7

Describe Lermoyez syndrome.

Answer 7

Tinnitus and hearing loss that remit after an attack of vertigo

Question 8

Define possible, probable, definite and certain

Ménière disease.

Answer 8

● Possible: Episodic vertigo without documented hearing
loss or SNHL (fluctuating or fixed) with dysequilibrium
but without definitive vertigo episodes; other causes
excluded

● Probable: One definitive episode of vertigo, audiometri-
cally documented hearing loss on at least one occasion,

tinnitus or aural fullness in the treated ear; other causes
excluded
● Definite: Two or more definitive spontaneous episodes of
vertigo lasting 20 minutes or longer, audiometrically
documented hearing loss on at least one occasion,
tinnitus or aural fullness in the treated ear, other causes
excluded
● Certain: Definite Ménière disease plus histopathologic
confirmation

Question 9

Describe diet modifications for treatment of

Ménière disease.

Answer 9

● Avoidance of alcohol, caffeine, tobacco and monosodium
glutamate
● Adherence to a low-sodium diet (less than 1 to 2 g/day)

Question 10

How is electrocochleography used in the diagnosis

of Ménière disease?

Answer 10

If the ratio of the summating potential, generated by the
organ of Corti, and the action potential, generated by the
auditory nerve, is elevated, diagnosis is indicated. A value
of 0.5 or greater is considered suggestive of Ménière
disease.

Question 11

How is electrocochleography performed?

Answer 11

Neural responses to presented sounds are recorded
through an electrode in the middle ear (transtympanic
needle electrode), on the tympanic membrane, or on a gold
foil-wrapped earplug.

Question 12

What is the role of intratympanic injections of

gentamicin in the treatment of Ménière disease?

Answer 12

● Selectively vestibulotoxic ablative treatment for unilateral
Ménière disease, often pursued after failure of more
conservative measures such as low-salt diet, caffeine
avoidance, diuretic therapy, and intratympanic steroid
injection
● Carries a 5 to 20% chance of significant SNHL

Question 13

What is the role of intratympanic injections of corticosteroids in the treatment of Ménière dis-
ease?

Answer 13

These injections are onsidered a nonablative adjunct to
medical therapy that carries little risk of inducing hearing
loss. Subjects may experience a brief episode of vertigo
with injection if the steroid is not body temperature
and a low risk for persistent tympanic membrane
perforation.

Question 14

When is a patient considered a candidate for

endolymphatic sac surgery?

Answer 14

Frequent vertiginous spells despite conservative treatment
in patients who are not candidates for ablative procedures
(bilateral disease, good residual hearing, contralateral
vestibular hypofunction)

Question 15

What is the Donaldson line?

Answer 15

The Donaldson line is an imaginary line running parallel to
the plane of the lateral semicircular canal, extending
posteriorly and inferiorly through the center of the
posterior semicircular canal. The endolymphatic sac lies just
inferior to this line on the posterior fossa dura.

Question 16

What pure tone audiometric findings can be seen in patients with superior semicircular canal dehiscence?

Answer 16

Conductive hyperacusis is sometimes seen, with bone
conductive thresholds occasionally less than 0-dB hearing
loss. This can lead to an air-bone gap even when air
conductive thresholds are within the normal range.

Question 17

Describe the third window phenomenon.

Answer 17

The third window refers to a third opening in the inner ear,
in addition to the round and oval windows, that permits
pathological movement of perilymph within the labyrinth,
which may induce vertigo.

Question 18

Describe the clinical presentation of superior

semicircular canal dehiscence syndrome.

Answer 18

Aural fullness, autophony, hearing loss (generally with an
air-bone gap and often supranormal bone conduction), and
dizziness often associated with loud sounds, exertion or
straining

Question 19

How can one differentiate otosclerosis from superior semicircular canal dehiscence syndrome?

Answer 19

Patients with otosclerosis often have type AS tympanograms, diphasic or absent stapedial reflexes, and elevated to absent cervical vestibular evoked myogenic potentials.
Patients with superior semicircular canal dehiscence will usually have normal stapedial reflexes, type A tympano-
grams, and diminished vestibular evoked myogenic poten-
tial thresholds (often < 70 dB).

Question 20

How do you perform and interpret the Dix-

Hallpike test?

Answer 20

With the patient sitting, rotate the patient’s head by
approximately 45 degrees to the left or the right. The
patient then lies flat with the head slightly extended (~ 20
degrees). The eyes are then observed for ~ 45 seconds
looking for rotary nystagmus. If rotatory nystagmus occurs,
the test is positive. The direction of the fast phase reveals
the side that is affected.

Question 21

Describe the clinical manifestation of benign

paroxysmal positional vertigo?

Answer 21

Short-lived (less than 60 seconds), room-spinning vertigo

provoked by head turn

Question 22

Which semicircular canal is most commonly

involved in benign paroxysmal positional vertigo?

Answer 22

Posterior canal. Five percent involve the horizontal canal

and the superior canal is the least common.

Question 23

What anatomical structure is the source of

otoconia in benign paroxysmal positional vertigo?

Answer 23

The utricle

Question 24

What are risk factors for the development of

benign paroxysmal positional vertigo?

Answer 24

● Advanced age, head trauma, surgery, migraine
● Most patients do not have an identifiable cause (idio-
pathic).

Question 25

Describe the mechanism of singular neurectomy in the treatment of benign paroxysmal positional vertigo.

Answer 25

The singular nerve innervates the posterior semicircular canal, which is the most commonly affected canal in benign paroxysmal positional vertigo. Division of this nerve may lead to symptom relief in refractory disease.

Question 26

What conservative treatment options are available | for benign paroxysmal positional vertigo?

Answer 26

● Reassurance and education about the nature of the condition ● No effective pharmacologic therapy is available ● Canalith repositioning maneuvers involve taking a patient through a series of positions that are designed to return dislodged otoconia to the vestibule and are the most effective nonsurgical treatment.

Question 27

``` What test(s) should be ordered when vertebro- basilar insufficiency is suspected? ```

Answer 27

● MRI and magnetic resonance angiography (MRA) provide the best information regarding acute and chronic infarcts, as well as the location and severity of vascular occlusions in the head and neck. ● Patients who cannot undergo MRI should be evaluated with CT and CT angiography (CTA). ● Duplex ultrasound can also provide information regarding proximal vertebral arteries.

Question 28

What symptoms may accompany episodic vertigo | associated with vertebrobasilar insufficiency?

Answer 28

Diplopia, decrease in visual acuity, ataxia, dysarthria, | dysphagia, and other focal neurologic symptoms

Question 29

Describe the symptoms of Wallenberg syndrome.

Answer 29

● Loss of pain and temperature sensation on the ipsilateral face and contralateral body, dysphagia, dysarthria, ataxia, vertigo, Horner syndrome, diplopia ● Caused by a lateral medullary infarct supplied by the posterior inferior cerebellar artery

Question 30

What are typical initial symptoms of vestibular | neuronitis?

Answer 30

● Sudden onset of severe vertigo, nausea, and vomiting lasting days to weeks, often preceded by a viral upper respiratory tract infection ● Unlike labyrinthitis, hearing should remain stable.

Question 31

What are the mainstays of treatment for vestibular | neuronitis?

Answer 31

High-dose corticosteroids, vestibular suppressants in the | acute period, antiemetics, and bed rest as needed

Question 32

What are the diagnostic criteria for chronic | subjective dizziness?

Answer 32

● Subjective unsteadiness or nonvertiginous dizziness that is present for 3 + months and is present most days ● Hypersensitivity to one's own motion and to the move- ment of objects in the environment ● Visual dizziness marked by exacerbation of symptoms in settings with complex visual stimuli (grocery stores) or when performing precision visual tasks (reading or working on the computer)

Question 33

What are the treatment options for chronic | subjective dizziness?

Answer 33

First-line pharmacologic therapy includes selective seroto- nin reuptake inhibitors. For patients with concurrent migraine, selective serotonin norepinephrine reuptake inhibitors or tricyclic antidepressants may be used. Behavioral intervention and psychoeducation serve as comple- menting therapies.

Question 34

Describe the typical presentation of mal de débarquement syndrome.

Answer 34

The sensation of rocking or swaying back and forth without vertigo, difficulty concentrating, and fatigue. It most commonly occurs in middle-aged women after a week-long cruise. The mean duration of symptoms is 3.5 years.

Question 35

What is the mechanism of motion sickness?

Answer 35

Disagreement between vestibular cues and visual and | somatosensory input

Question 36

Excluding benign paroxysmal positional vertigo, what is the most common cause of vertigo in the general population?

Answer 36

Vestibular migraine, or migraine-associated vertigo, is estimated to have a prevalence of ~ 1% in the general population.

Question 37

What are the diagnostic criteria for vestibular | migraine?

Answer 37

Definite vestibular migraine ● Recurrent episodic vestibular symptoms of at least moderate severity ● Current or previous history of migraine ● Migrainous symptoms during ≥ 2 vertiginous attacks ● Other causes ruled out by appropriate investigations Probable vestibular migraine ● Recurrent episodic vestibular symptoms of at least moderate severity ● One of the following: ○ Current or previous history of migraine ○ Migrainous symptoms during ≥ 2 attacks of vertigo ○ Migraine precipitants before vertigo in more than 50% of attacks ○ Response to migraine medications in more than 50% of attacks ○ Other causes are ruled out by appropriate investiga- tions.

Question 38

Describe the relationship between vestibular mi- | graine and Ménière disease.

Answer 38

There is substantial overlap between groups. Approximately one-fourth of patients with Ménière disease also fulfill diagnostic criteria for vestibular migraine.

Question 39

Describe the clinical features of basilar migraine.

Answer 39

● Similar symptoms to vertebrobasilar insufficiency with headache ● Most patients experience dizziness but may also experi- ence ataxia, hearing loss, tinnitus, dysarthria, diplopia, and syncope. ● It most commonly involves young females.

Question 40

Describe the common neurotologic examination | findings in patients with multiple sclerosis.

Answer 40

Abnormalities of smooth pursuit (96%), saccadic eye movements (76%), optokinetic nystagmus (53%), and defective visual suppression of nystagmus (43%)

Question 41

What is the Charcot triad?

Answer 41

Nystagmus, scanning speech, and intention tremor; asso- | ciated symptoms of multiple sclerosis

Question 42

Define balance retraining therapy.

Answer 42

Specialized form of physical therapy focusing on the improvement of static and dynamic balance and gait, and promoting central vestibular compensation by taking advantage of the inherent plasticity of central balance pathways

Question 43

What are the two phases of vestibular recovery | after an acute vestibular insult?

Answer 43

● Static recovery (initial phase) occurs through a central adaptive process that rebalances tonic neural activity between vestibular nuclei ● Dynamic recovery (second phase) involves recalibrating brain and cerebellar reflex pathways in response to sensory conflicts occurring with head and eye move- ments.

Question 44

Describe the clinical findings during static compensation and dynamic compensation.

Answer 44

During static compensation, patients will often have marked spontaneous nystagmus and vertigo lasting from days to weeks. During dynamic compensation, patients may experience general imbalance and unsteadiness with quick head turn.

Question 45

With regard to vestibular rehabilitation, describe | the strategy of adaptation.

Answer 45

Exercises aimed at improving vestibule-ocular response (VOR) gain. Initially, the patient is asked to view a stationary object while moving the head back and forth. The same exercise can be repeated but with the object moving in the opposite direction of head turn. This will strengthen gaze stability through improvement of the VOR response.

Question 46

With regard to vestibular rehabilitation, describe | the strategy of habituation.

Answer 46

Patients may be exposed to repetitive visual, vestibular, or motor exercises that are designed to provoke episodes of imbalance. With repetitive exposure, there is an attenuation or modification of the response.

Question 47

With regard to vestibular rehabilitation, describe | the strategy of substitution.

Answer 47

``` Exercises designed to take advantage of alternate intact balance mechanisms (remaining vestibular function, visual input, somatosensory input) to compensate for specific balance system deficits ```

Question 48

Describe the ideal candidate for vestibular rehabilitation.

Answer 48

Patient with stable unilateral vestibular hypofunction who continues to feel general imbalance that is worsened by quick head movements

Question 49

What patients are not good candidates for | vestibular rehabilitation?

Answer 49

Central compensation requires consistent and predictable peripheral vestibular input; therefore, patients with un- stable vestibular deficits (e.g., active Ménière disease, acute viral labyrinthitis) should not enter vestibular rehabilitation until their condition has stabilized.

Question 50

Name several conditions that negatively influence | the outcome of vestibular rehabilitation.

Answer 50

Coexisting conditions that affect balance may result in less optimal outcomes than in patients with isolated stable vestibular hypofunction. Examples include central nervous system disorders (stroke, multiple sclerosis, Parkinson disease), sensory neuropathy (diabetes, peripheral vascular disease), motor dysfunction, and patients with vestibular migraine, to name a few.

Question 51

Which medications potentially retard progress | during vestibular rehabilitation?

Answer 51

Anticonvulsants and sedating medications may prolong vestibular rehabilitation. Additionally, vestibular suppressive medications hinder initial static compensation.

Question 52

To what does presbystasis refer?

Answer 52

Presbystasis refers to the general balance difficulties of elderly patients that is related to cumulative age-related decline in vestibular response, visual acuity, proprioception, and motor control.

Question 53

What diagnosis must be considered with hearing evaluation with low frequency conductive loss with stapedius reflexes present?

Answer 53

Superior Semicircular Canal Dehiscence