2. Meniere’s disease is defined as a symptom complex associated with:
1. Roaring tinnitus
2. Sensorineural hearing loss (Low frequency)
3. Vertigo (episodic)
4. Fullness of the ear
5. These symptoms are associated with dilated membranous
labyrinth filled with endolymph
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3. 1. 1747 – Antonio Scarpa described anatomy of membranous
labyrinth
2. 1861 – Prosper Meniere described the classic features of
Meniere’s disease & attributed it to labyrinthine causes
3. 1871 – Knappin theorized that dilated membranous labyrinth to
be the cause of this disorder
4. 1927 – Guild described endolymphatic ciruclation
5. 1938 – Hallpike and Portmann described pathology of Meniere’s
disease by studying temporal bones.
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4. 1. 150 years have passed since this syndrome was described
2. Amount of literature accumulated has virtually doubled
3. Only consensus reached so far is that its cause is multifactorial
4. Not all individuals with histological features of Meniere’s disease
manifested the classic clinical features (? Unknown factors
protecting the individuals)
5. Surgical destruction of sac ameliorates symptoms. (? What role
does sac play exactly in endolymphatic circulation)
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5. 1. Inner ear contains two types of fluids (perilyimph and endolymph
separated by membranous labyrinth.
2. Perilymph is similar in composition to CSF (Containing high Na and low K
ions)
3. Endolymph similar in composition to intracellular fluid (Containing low Na
and high K concentration). It is secreted by stria vascularis
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6. Duct begins at ductus reuniens
Duct is a single lumen tube
about 2 mm long
The duct narrows at the isthmus
which lies at the level of
vestibular aqueduct
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7. 1. Secretory function
2. Absorptive function
3. Immune / defense function
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8. 1. Aquaporins
2. Glycoproteins like Saccain
3. Endolymph
4. Glycoproteins act as a driving force
for longitudinal flow
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10. 1. Was first proposed by Guild
2. Striavascularis is the principal source
3. This is a slow process
4. Elimination occurs at the endolymphatic
sac level
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11. 1. First proposed by Lawrence
2. This is a combination of both
longitudinal and radial flow patterns
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12. 1. This is active process (energy consuming)
2. Production occurs from dark vestibular cells &
planum semilunatum
3. Absorption occurs at the striavestibularis
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13. 1. This is a small membranous bulb located where the
endolymphatic duct enters the vestibule
2. This is where the volume of circulating endolymph is monitored
3. Monitoring the volume of endolymph is not possible by sac
because it will be interfered by CSF pressure and pressure
exerted by lateral sinus
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15. 1. Composition of endolymph is maintained by stria vascularis by controlling
the influx of water
2. Normally endolymph is a biological puddle with very little radial /
longitudinal flow
3. Only under exceptional circumstances like increased endolymphatic fluid
volumes does radial / longitudinal movement towards sac occurs
4. Under normal circumstances radial flow alone is sufficient to maintain
endolymph fluid balance and the longitudinal flow due to saccmechanics is
not necessary
5. The longitudinal flow is restricted by the isthmus portion of the duct which
acts like the constriction seen in the hour glass
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19. 1. Small amounts of excess endolymph can be cleared by radial flow
2. Larger volumes need longitudinal flow for their clearance
3. Endolymphatic sinus temporarily accommodates excess endolymph till
the sac is ready for it
4. Endolymphatic valve of Bast isolates pars superior and prevents
endolymph from draining out of the utricle
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22. This is a variant of Meniere’s disease. It is characterized by sudden sensori
neural hearing loss which improves during or immediately after the attack of
vertigo.
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23. This variant is characterized by abrupt falling attacks of brief duration
without loss of consciousness. This is caused due to an enlarging utricle
due to excess endolymphatic volume. Utricular crisis is used to indicate
this condition.
In the later disease stages the valve of Bast remaining patent may cause
sudden drainage of endolymph from the utricle due to longitudinal flow
resulting in these drop attacks
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24. Roughly 1 in 1000 individuals are affected
Constitutes 10% of all patients attending vertigo clinic
Female preponderance
Rare in children under the age of 10
Commonly begins between 4th and 5th decades of life
Bilateral Meniere’s syndrome is seen in 5% of these patients
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25. 1. Endolymphatic hydrops causes distortion of membranous labyrinth
2. Pressure building up in the scala media may cause mirco ruptures of
membranous labyrinth
3. This would account for the episodic nature of the attacks
4. Healing of these ruptures causes resolution of the disorder
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27. 1. Stage I – Patient has solely cochlear symptoms
2. Stages II – IV – Patients have progressively more cochlear and
vestibular symptoms
3. Stage V – End stage Meniere’s disease (dead ear)
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28. 1. Irritative nystagmus during the first 20 mins of attack
2. Paralytic nystagmus follows
3. Later recovery nystagmus starts
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29. Possible Meniere’s disease:
Episodic vertigo of Meniere’s type without documented hearing loss
Fluctuating hearing loss with disequilibrium but without definite episodes
Probable Meniere’s disease:
One definitive episode of vertigo
Audiometrically documented hearing loss at least during one attack
Definitive Meniere’s disease
Two or more definitive episodes of spontaneous vertigo one atleast lasting for
20 mins.
Audiometrically documented hearing loss at least on one occasion
Tinnitus and aural fullness in the treated ear
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30. Sensori neural hearing loss combined with:
Tinnitus now / in the past
Vertigo attacks (at least two present now or in the past)
Exclusion of other pathology following Groningen protocol
Hearing loss:
Sensori neural in nature
No demonstrable conductive element
Hearing loss of 20 dB or more at one of the usually measured
audiometric thresholds
Vertigo:
Paroxysmal rotatory dizziness, accompanied by nausea / vomiting
At least two episodes should be reported during a course of illness.
One of the attack should last at least for 5 mins
In between attacks there may be periods of unsteadiness
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31. 1. Sensori neural in nature
2. Fluctuating and progressive
3. Affects low frequencies
4. Mild low frequency conductive hearing loss (rare)
5. Profound sensori neural hearing loss (End stage)
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32. Roaring in nature
Could be continuous / intermittent
Non pulsatile in nature
Frequency of tinnitus corresponds to the region of cochlea which has suffered
the maximum damage
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33. 1. This is abnormal growth in the perceived intensity of sound
2. This is usually positive in patients with Meniere’s disease
3. ABLB is the test used to look for the presence of recruitment
4. This test is really time consuming
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34. 1. Increased summating potential / action potential ratio. 1:3 is normal
2. Widened summating potential / action potential complex. A widening of
greater than 2 ms is significant
3. Small distorted cochlear microphonics
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35. 1. Not mandatory for diagnosis of Meniere’s disease
2. Caloric test is still performed
3. It is low frequency stimulation (0.003 Hz) of lateral canal
4. Caloric asymmetry will point to the diseased ear
5. 20% difference between the two ears (Jongkee’s formula) is significant
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36. 1. Vestibular evoked myogenic potential
2. Measures the relaxation of sternomastoid muscle in response to ipsilateral click
stimulus
3. Brief high intensity ipsilateral clicks produce large short latency inhibitory
potentials (VEMP) in the toncially contracted Ipsilateral sternomastoid muscle
4. This test is due to the presence of vestibulo collic reflex
5. Afferent arises from sound responsive cells in the saccule, conducted via the
inferior vestibular nerve.
6. Efferent is via vestibulo spinal tract
7. Normal responses are composed of biphasic (positive-negative) waves
8. VEMP reveals saccular dysfunction
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37. 1. Glycerol
2. Frusemide
3. Isosorbide
4. Tests are positive if there is pure tone improvement of 10dB or more
at two / more frequencies between 200-2000Hz
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38. 1. First introduced by Klockhoff and Lindblom – 1966
2. Glycerol is administered in doses of 1.5 mg/kg body wt in empty stomach
3. Serum osmolality should increase at least by 10 mos/kg
4. Side effects include Headache, Nausea, vomiting, drowsiness
5. PTA is performed 2-3 hours after administration
6. False positivity is rare
7. Positivity depends on the phase of the disease
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40. 1. Intravenous fluids – dehydration
2. Vestibular suppressants – May delay recovery / rehabilitation process
3. Corticosteroids – May help if tinnitus and deafness are debilitating
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41. 1. Frustenberg diet
2. 2 grams / 24 hours (restricted salt intake)
3. Life style modification
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42. 1. Diuretics play a vital role in alleviating acute symptoms
2. This has been in use since 1930’s
3. Thiazide group of drugs are commonly used
4. Frusemide may be used to alleviate acute symptoms
5. Clear scientific evidence is lacking regarding the usefulness of diuretics
(cochrane review)
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43. 1. Cochlear vascular insufficiency has been proposed as one of the
mechanism of Meniere's disease
2. Betahistine is supposed to cause vasodilatation of cochlear blood
vessels
3. Betahistine has weak H1 agonistic property and considerable H3
antagonist properties
4. It reduces the frequency & intensity of vertigo. Has minimal effect on
tinnitus
5. Doesn’t help much with hearing loss (Cochrane review)
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44. 1. Immune modulating effects
2. Improves fluid dynamics of inner ear due to mineralocorticoid effects
3. Vertigo was controlled on an immediate basis
4. Methylprednisolone has the best effect as it penetrates the round window
better
5. Silverstein microwick can be used for intratympanic drug administration
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45. 1. Isordil
2. ϒ – globulin
3. Urea
4. Glycerol
5. Lithium
6. Anticholinergics – Glycopyrrolate 1-2 mg /day
7. Antidopaminergics – Droperidol 2.5 – 10 mg orally / day
8. Leuprolide acetate – Blocks normal sex hormone production
9. Innovar – A combination of droperidol and fentanyl can be used to
suppress vestibular symptoms (can replace endolymphatic sac surgery)
10. Hyperbaric oxygen therapy
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46. 1. Stress reduction
2. Patient education
3. Hearing aids – can be used to suppress troublesome tinnitus
4. Tinnitus retraining
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47. 1. Meniett Device
2. Low pressure pulse generator
3. Vibrations are transmitted via external
auditory canal
4. Vibrations alter inner ear fluid dynamics by
their effects on the oval and round
windows
5. Exact mechanism of action is not known
6. It is totally non invasive
7. This device is portable
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48. 1. Diagnosis should be confirmed
2. Ventilation tube should be inserted
3. Patient should be trained for self administration of the treatment
4. Usually administered thrice a day about 5 mins each time
5. Treatment lasts for 5 weeks
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49. 1. Classic unilateral Meniere’s disease
2. Intense vestibular / cochlear symptoms
3. Failed medical therapy
4. Over 65 years of age
5. Imbalance / aural fullness / tinnitus after gentamycin treatment
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51. 1. Vestibulotoxic effects are put to therapeutic use.
2. Sensation of vertigo reduced while hearing is preserved
3. Streptomycin / gentamycin are predominantly Vestibulotoxic
4. Intratympanic administration is preferred
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52. 1. Fixed dose protocol is used
2. 40 mg/ml gentamycin is buffered with soda bicarb (pH6.4) final concentration
26.7mg/ml.
3. T tube grommet inserted into the postero inferior quadrant of ear drum. A
mcirocatheter is inserted through the grommet
4. 1ml of gentamycin solution is injected into the middle ear cavity via the
microcatheter
5. Three injections are given per day in outpatient setting
6. Injections are given for 4 days
7. After injection patient should lie supine with the infiltrated ear up for 30 mins
8. Vertigo usually develops between 2-4 days after cessation of treatment
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54. 1. External shunts – Drains the sac into mastoid cavity / subarachnoid space
2. Internal shunts – Drains excessive endolymph into the perilymphatic space
(cochleosacculotomy / labyrinthotomy)
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56. 1. Helpful in treating debilitated patients
2. Involves disruption of osseous spiral lamina
3. Angular pick introduced via round window towards oval window. It will
accommodate 3 mm long pick
4. After perforation the pick is withdrawn and the round window is sealed by
fat
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Schematic of how the endolymphatic sinus detects and regulates endolymph volume status. When endolymph volume is normal (left), pressure elevations in the vestibule (black arrow) produce only small endolymph movements into the sac before the sinus membrane occludes the duct. In contrast, when the endolymphatic sinus is dilated (right), pressure elevations in the vestibule result in a larger volume being forced into the sac before the duct is occluded. The increase in volume delivered to the sac with dilation of the endolymphatic sinus will act to counteract the volume increase, acting to stabilize endolymph volume within a specific range.
The excess volume tends to accumulate in the apical end of the cochlea, where the membranes are more lax than elsewhere, even though the endolymph pressure would be similar elsewhere in the cochlea.