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Flashcards in Vertigo Deck (92):
1

A patient with Meniere's disease has been disabled for > 1 year and is on disability. What functional level is he/she

6

2

What % of patients with Meniere's disease do not respond adequately to salt restriction and diuretics

1 O%.

3

What is the treatment for otosyphilis

2.4 million U of benzathine penicillin IM q week for at least 3 weeks (up to I year) or I 0 million U of penicillin G IV qd for 10 days followed by 2.4 million U of I M benzathine penicillin q week for 2 weeks plus prednisone 40 - 60 mg qd for 2 - 4 weeks followed by a taper.

4

What % of patients with classic migraine experience vertigo

30 - 40%.

5

What is the rate of recurrence

30 - 50% eventually have a recurrence; 10 - 20% within I - 2 weeks of the maneuver.

6

What happens to the SP in the presence of hydrops

36% of patients will have a normal SP~ 32% will have a moderately enhanced negative SP; 27% will have a very enhanced negative SP; 5% will have no SP or action potential.

7

What % of patients with hearing loss secondary to otosyphilis improve with penicillin and steroid therapy

3I %.

8

A patient with Meniere's disease is able to work, drive, and travel but must exert a great deal of effort to do so and is "barely making it." What functional level is he/she

4 (out of 6).

9

After aminoglycoside treatments, when is the usual onset of dysequilibrium

4 days after treatment.

10

What is the success rate of the Epley maneuver after only 1 manipulation

50 -77%.

11

What % of patients will have improved tinnitus and hearing after endolymphatic sac surgery

50°/o experience improvement in tinnitus and 30 - 40% experience improvement in hearing.

12

What % of patients with vertigo secondary to otosyphilis improve with penicillin and steroid therapy

58 - 86%.

13

What % of patients have improvement of vertigo after endolymphatic sac surgery

70°/o experience complete relief, 20% experience decreased vertigo.

14

What is the success rate of singular neurectomy

79-94%.

15

What is the success rate after 2 manipulations

95 - 97%.

16

What are the most common manifestations of VBI

Abrupt, transient attacks of vertigo associated with bilaterally reduced caloric responses.

17

What is the treatment for this syndrome

Acetazolamide.

18

What 3 variables does it measure

Action potential (AP), summating potential (SP), and cochlear microphonic (CM).

19

What % of patients have bilateral Meniere's disease

After 2 years, 15% of patients; after I 0 years, 25 - 35%; and after 20 years, 40 - 60°/o.

20

Which aminoglycosides are primarily cochleotoxic

Amikacin, dihydrostreptomycin, kanamycin, and streptomycin at high doses.

21

What disorders are associated with down-beating nystagmus

Amold-Chiari, cerebellar degeneration, multiple sclerosis, brainstem infarction, lithium intoxication, magnesium and thiamine deficiency.

22

Where is the endolymphatic sac

Anterior to Trautmann's triangle within the dura, medial and inferior to the posterior semicircular canal.

23

Which way is the sigmoid sinus retracted in the retrosigmoid approach to vestibular nerve section

Anteriorly.

24

What is the treatment for vertigo secondary to VBI

Aspirin or ticlid if aspirin-sensitive.

25

What disorders are associated with bidirectional gaze-fixation nystagmus

Barbiturate, phenytoin, and alcohol intoxication.

26

What region of the inner ear is most susceptible to permanent loss of hair cells

Basal turn of the cochlea.

27

What are the most widely used agents for prophylaxis of migraine

Beta-blockers and calcium antagonists.

28

How do aminoglycosides exert their toxic effects on the hair cells of the inner ear

Bind to the plasma membrane and displace calcium and magnesium; once transported into the cell, bind with phosphatidylinositol, causing disruption of the plasma membrane and inhibition of inositol triphosphate, resulting in cell death.

29

Which of these is superior in complete elimination of vertigo

Both are equally effective.

30

What disorders are associated with up-beating nystagmus

Brainstem tumors, congenital abnormalities, multiple sclerosis, hemangiomas, vascular lesions, encephalitis, and brainstem abscess.

31

What are the deposits thought to consist of

Calcium carbonate crystals, possibly resulting from microfractures of the temporal bone near the round window niche (also near the ampulla of the posterior SCC).

32

Which theory is currently more favored

Canalolithiasis.

33

What features distinguish BPPV from vertigo due to CNS disease

CNS disease: no latent period, direction of nystagmus varies, nystagmus and vertigo are nonfatiguable.

34

What are the criteria for "possible" Meniere's disease

Cochlear or vestibular variants of Meniere's for which other causes have been excluded.

35

What are the 2 main theories of the pathophysiology of BPPV

Cupulolithiasis theory: deposits gravitate, attach to, and stimulate the cupula. Canalolithiasis theory: deposits float freely within the semicircular canals (SCC) under the influence of gravity.

36

What happens to the SP when the basilar membrane is displaced towards the scala media

Decreases or reverses polarity.

37

How does this theory account for the latency of onset of nystagmus

Delay is due to the adherence of deposits to the membranous wall of the labyrinth.

38

What happens to CM in the presence of hydrops

Diminishes; after-ringing may occur.

39

What clinical findings are diagnostic of central vestibular disorders

Disconjugate eye movements, skew deviation, vertical gaze palsy, inverted Bell's phenomenon, seesaw nystagmus, bidirectional nystagmus, periodic alternating nystagmus, and nystagmus that is greater with eyes open and fixed on a visual target than in darkness.

40

What is the mainstay of treatment for Meniere's disease

Diuretics and dietary salt restriction.

41

What increases the likelihood of headaches after the retrosigmoid approach

Drilling out of the medial portion of the lAC.

42

What are the surgical options for treatment of Meniere's

Endolymphatic shunt, destructive labyrinthectomy, and vestibular nerve section.

43

Which of these is the only surgical procedure considered in an only-hearing ear

Endolymphatic shunt.

44

Which of these is most commonly performed

Endolymphatic shunt.

45

What therapeutic maneuver is based on the canalolithiasis theory

Epley.

46

What are the most widely used agents for treatment of acute migraine

Ergotamine tartrate and sumatriptan.

47

What is the primary problem of IM penicillin therapy for otosyphilis

Fails to achieve treponemicidal levels in the CSF.

48

What syndrome is characterized by recurrent episodes of vertigo and ataxia in several members of a family

Familial ataxia syndrome.

49

What is the Jarisch-Herxheimer reaction

Fever and flu-like symptoms beginning within 4 hours of commencing treatment for secondary syphilis.

50

What is the success rate of vestibular nerve section

For the middle fossa approach, complete elimination of vertigo is achieved in >90%; for the posterior approaches, complete elimination of vertigo is achieved in >80%.

51

Which aminoglycosides are primarily vestibulotoxic

Gentamicin and streptomycin.

52

What is the glycerol test for Meniere's

Glycerol given orally increases the serum osmolality, causing a shift of water and electrolytes from the perilymph and CSF to the serum, and increases cochlear blood flow. In most patients with Meniere's, this will result in an improvement in hearing.

53

What are the landmarks for identification of the lAC during middle fossa approach to vestibular nerve section

Greater superficial petrosal nerve, malleus head, and superior SCC.

54

What is the incidence of total SNHL after endolymphatic sac surgery

I - 2%.

55

What are the clinical features of BPPV

I 0-20 second attacks of rotational vertigo, precipitated by head movements, with spontaneous resolution after several weeks to months in 80-90%.

56

According to AAO-HNS, what are the criteria for "definite" Meniere's disease

I) 2 or more episodes of spontaneous rotational vertigo lasting 20 minutes or longer. 2) Audiometrically documented hearing loss on at least one occasion. 3) Tinnitus or aural fullness in the affected ear. 4) Exclusion of other causes.

57

How is ECochG helpful prior to destructive surgery for Meniere's disease

In patients with unilateral disease, abnormalities in the asymptomatic ear (SP:AP >35°/o, distorted CM with after-ringing) predict development of hydrops in that ear.

58

What are the indications for surgical treatment of BPPV

Incapacitating symptoms > 1 year, confirmation of BPPV with Dix-Hallpike on at least 3 visits, failure of conservative treatment, normal head M Rl.

59

What happens to the SP when the pressure increases inside the scala media

Increases (basilar membrane is displaced towards the scala tympani).

60

What is the significance of a positive test

Indicates hydrops, which can be caused by Meniere's, late syphilis, Cogan's disease, otosclerosis, or acoustic neuroma.

61

What portion of the Vlllth nerve is sectioned in vestibular nerve section

Lateral portion (superior and inferior vestibular nerves) in the lAC.

62

What do the utricle and saccule detect

Linear acceleration.

63

What are the metabolic effects of prolonged thiazide diuretic therapy

Metabolic alkalosis with hypokalemia and hypochloremia, hyperglycemia.

64

What are the 4 primary approaches to vestibular nerve section

Middle fossa, retrosigmoid, transcochlear, and retrolabyrinthine.

65

Which of these is associated with the greatest risk of damage to VII

Middle fossa.

66

What are the contraindications to vestibular nerve section

Only hearing ear, signs of central vestibular dysfunction, poor medical health.

67

What are the criteria for "probable" Meniere's disease

Only I episode of vertigo plus the other criteria for "definite" disease.

68

What is the prognostic significance of a normal AP-SP prior to surgery

Outcomes are significantly better.

69

Which patients are least likely to benefit from vestibular rehabilitation programs

Patients with fluctuating nonstable vestibular lesions such as with Meniere's disease; patients in whom no provocative maneuvers or postural control abnormalities are found on examination.

70

In terms of functional level, which patients with Meniere's disease are candidates for chemical or surgical labyrinthectomy

Patients with functional levels of 4, 5, or 6.

71

What is the most common and most difficult to manage problem after any vestibular destructive surgery

Persistent dysequilibrium (20%).

72

What % of cases occur in the posterior SCC? Horizontal SCC

Posterior 80 - 95%; horizontal 5 - 20%.

73

Which way is the sigmoid sinus retracted in the retrolabyrinthine approach to vestibular nerve section

Posteriorly.

74

What does computerized dynamic platform posturography specifically measure

Postural stability and sway.

75

What medication extends the half-life and facilitates CSF penetration of penicillin

Probenecid.

76

What is the earliest indicator of hydrops on ECochG

Ratio of SP to AP >30%.

77

Why is posterior SCC ablation most often the procedure of choice

Relatively easier, less risk to hearing, excellent long term results (approaches 1 OO%).

78

Which of these approaches is at higher risk for a CSF leak

Retrolabyrinthine.

79

Which of these is most likely to result in postoperative headaches

Retrosigmoid.

80

Why is ticlid only warranted in patients unable to tolerate aspirin

Risk of life-threatening neutropenia.

81

Which part of the vestibular labyrinth detects angular acceleration

Semicircular canals.

82

Where are cupula found

Semicircular canals.

83

What therapeutic maneuver is based on the cupulolithiasis theory

Semont.

84

What are the surgical options for treatment of BPPV

Singular neurectomy, posterior SCC ablation.

85

What clinical finding is pathognomonic for a lesion at the craniocervical junction

Spontaneous downbeat nystagmus with the eyes open, in the primary position that increases with lateral gaze or head extension.

86

What are the disadvantages of singular neurectomy

Technically difficult, I 0% risk of SNHL, and nerve may be inaccessible under the basal turn of the cochlea in a small number of patients.

87

What are the criteria for "certain" Meniere's disease

The above criteria plus histopathologic confirmation.

88

What is the most important factor in the ototoxic effect of aminoglycosides

Total cumulative dose.

89

What are the 2 approaches to labyrinthectomy

Transmastoid and transcanal.

90

What is the most consistently reliable objective test for hydrops

Transtympanic electrocochleography ( ECochG ).

91

Balance is determined by what 3 systems

Vestibular, vestibulo-ocular (visual), and vestibulospinal (proprioceptive) systems.

92

What are the physical exam findings in patients with BPPV

With the Dix-Hallpike maneuver, rotatory nystagmus towards the undermost ear accompanied by vertigo, both with a latent period of 5-30 s and duration