Vertigo Flashcards
A patient with Meniere’s disease has been disabled for > 1 year and is on disability. What functional level is he/she
6
What % of patients with Meniere’s disease do not respond adequately to salt restriction and diuretics
1 O%.
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.
What % of patients with classic migraine experience vertigo
30 - 40%.
What is the rate of recurrence
30 - 50% eventually have a recurrence; 10 - 20% within I - 2 weeks of the maneuver.
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.
What % of patients with hearing loss secondary to otosyphilis improve with penicillin and steroid therapy
3I %.
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).
After aminoglycoside treatments, when is the usual onset of dysequilibrium
4 days after treatment.
What is the success rate of the Epley maneuver after only 1 manipulation
50 -77%.
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.
What % of patients with vertigo secondary to otosyphilis improve with penicillin and steroid therapy
58 - 86%.
What % of patients have improvement of vertigo after endolymphatic sac surgery
70°/o experience complete relief, 20% experience decreased vertigo.
What is the success rate of singular neurectomy
79-94%.
What is the success rate after 2 manipulations
95 - 97%.
What are the most common manifestations of VBI
Abrupt, transient attacks of vertigo associated with bilaterally reduced caloric responses.
What is the treatment for this syndrome
Acetazolamide.
What 3 variables does it measure
Action potential (AP), summating potential (SP), and cochlear microphonic (CM).
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.
Which aminoglycosides are primarily cochleotoxic
Amikacin, dihydrostreptomycin, kanamycin, and streptomycin at high doses.
What disorders are associated with down-beating nystagmus
Amold-Chiari, cerebellar degeneration, multiple sclerosis, brainstem infarction, lithium intoxication, magnesium and thiamine deficiency.
Where is the endolymphatic sac
Anterior to Trautmann’s triangle within the dura, medial and inferior to the posterior semicircular canal.
Which way is the sigmoid sinus retracted in the retrosigmoid approach to vestibular nerve section
Anteriorly.
What is the treatment for vertigo secondary to VBI
Aspirin or ticlid if aspirin-sensitive.
What disorders are associated with bidirectional gaze-fixation nystagmus
Barbiturate, phenytoin, and alcohol intoxication.
What region of the inner ear is most susceptible to permanent loss of hair cells
Basal turn of the cochlea.
What are the most widely used agents for prophylaxis of migraine
Beta-blockers and calcium antagonists.
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.
Which of these is superior in complete elimination of vertigo
Both are equally effective.
What disorders are associated with up-beating nystagmus
Brainstem tumors, congenital abnormalities, multiple sclerosis, hemangiomas, vascular lesions, encephalitis, and brainstem abscess.
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).
Which theory is currently more favored
Canalolithiasis.
What features distinguish BPPV from vertigo due to CNS disease
CNS disease: no latent period, direction of nystagmus varies, nystagmus and vertigo are nonfatiguable.
What are the criteria for “possible” Meniere’s disease
Cochlear or vestibular variants of Meniere’s for which other causes have been excluded.
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.
What happens to the SP when the basilar membrane is displaced towards the scala media
Decreases or reverses polarity.