1. Dr T Balasubramanian MS DLO
Meniere’s Disease
Dr T Balasubramanian MS DLO

2. Definition
Meniere’s disease is defined as a symptom complex associated with:
Roaring tinnitus
Sensorineural hearing loss (Low frequency)
Vertigo (episodic)
Fullness of the ear
These symptoms are associated with dilated membranous labyrinth filled with endolymph

3. History
1747 – Antonio Scarpa described anatomy of membranous labyrinth
1861 – Prosper Meniere described the classic features of Meniere’s disease & attributed it to labyrinthine causes
1871 – Knappin theorized that dilated membranous labyrinth to be the cause of this disorder
1927 – Guild described endolymphatic ciruclation
1938 – Hallpike and Portmann described pathology of Meniere’s disease by studying temporal bones.

4. Where do we stand?
150 years have passed since this syndrome was described
Amount of literature accumulated has virtually doubled
Only consensus reached so far is that its cause is multifactorial
Not all individuals with histological features of Meniere’s disease manifested the classic clinical features (? Unknown factors protecting the individuals)
Surgical destruction of sac ameliorates symptoms. (? What role does sac play exactly in endolymphatic circulation)

5. Physiology of inner ear fluids
Inner ear contains two types of fluids (perilyimph and endolymph separated by membranous labyrinth.
Perilymph is similar in composition to CSF (Containing high Na and low K ions)
Endolymph similar in composition to intracellular fluid (Containing low Na and high K concentration). It is secreted by stria vascularis

6. Anatomy of Sac 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

7. Functions of sac Secretory function Absorptive function
Immune / defense function

8. Secretions from the sac
Aquaporins
Glycoproteins like Saccain
Endolymph
Glycoproteins act as a driving force for longitudinal flow

9. Endolymphatic fluid circulation
Longitudinal flow
Radial flow
Dynamic flow

10. Longitudinal flow Was first proposed by Guild
Striavascularis is the principal source
This is a slow process
Elimination occurs at the endolymphatic sac level

11. Dynamic flow First proposed by Lawrence
This is a combination of both longitudinal and radial flow patterns

12. Radial flow This is active process (energy consuming)
Production occurs from dark vestibular cells & planum semilunatum
Absorption occurs at the striavestibularis

13. Endolymphatic sinus
This is a small membranous bulb located where the endolymphatic duct enters the vestibule
This is where the volume of circulating endolymph is monitored
Monitoring the volume of endolymph is not possible by sac because it will be interfered by CSF pressure and pressure exerted by lateral sinus

14. How endolymphatic sinus monitors endolymph volume
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.

15. Salt’s findings on endolymphatic flow
Composition of endolymph is maintained by stria vascularis by controlling the influx of water
Normally endolymph is a biological puddle with very little radial / longitudinal flow
Only under exceptional circumstances like increased endolymphatic fluid volumes does radial / longitudinal movement towards sac occurs
Under normal circumstances radial flow alone is sufficient to maintain endolymph fluid balance and the longitudinal flow due to saccmechanics is not necessary
The longitudinal flow is restricted by the isthmus portion of the duct which acts like the constriction seen in the hour glass

16. Mechanism of Meniere’s disease

17. Lake pond hypothesis

18. Drainage theory
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.

19. Drainage theory (contd)
Small amounts of excess endolymph can be cleared by radial flow
Larger volumes need longitudinal flow for their clearance
Endolymphatic sinus temporarily accommodates excess endolymph till the sac is ready for it
Endolymphatic valve of Bast isolates pars superior and prevents endolymph from draining out of the utricle

20. Causes Genetic causes Infection Otosclerosis
Trauma (physical / acoustic)
Syphilis
Miscellaneous – Allergy, tumors, leukemia and autoimmune disorders

21. Types of Meniere's disease
Classical Meniere’s disease
Vestibular Meniere’s disease – vestibular symptoms and aural pressure
Cochlear Meniere’s disease – cochlear symptoms and aural pressure
Lermoyez syndrome – Reverse Meniere’s
Tumarkin’s crisis – Utricular Meniere’s

22. Lermoyez syndrome
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.

23. Tumarkin’s drop attacks
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

24. Incidence 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

25. Pathophysiology
Endolymphatic hydrops causes distortion of membranous labyrinth
Pressure building up in the scala media may cause mirco ruptures of membranous labyrinth
This would account for the episodic nature of the attacks
Healing of these ruptures causes resolution of the disorder

26. Clinical manifestations
Episodic vertigo rotatory in nature
Ipsilateral hearing loss
Aural fullness
Roaring tinnitus
Diplacusis

27. Stages Stage I – Patient has solely cochlear symptoms
Stages II – IV – Patients have progressively more cochlear and vestibular symptoms
Stage V – End stage Meniere’s disease (dead ear)

28. Direction of nystagmus
Irritative nystagmus during the first 20 mins of attack
Paralytic nystagmus follows
Later recovery nystagmus starts

29. Diagnostic criteria 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

30. Groningen criteria of diagnosis
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

31. Hearing loss Sensori neural in nature Fluctuating and progressive
Affects low frequencies
Mild low frequency conductive hearing loss (rare)
Profound sensori neural hearing loss (End stage)

32. Tinnitus 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

33. Loudness recruitment
This is abnormal growth in the perceived intensity of sound
This is usually positive in patients with Meniere’s disease
ABLB is the test used to look for the presence of recruitment
This test is really time consuming

34. Electro cochleography
Increased summating potential / action potential ratio. 1:3 is normal
Widened summating potential / action potential complex. A widening of greater than 2 ms is significant
Small distorted cochlear microphonics

35. Vestibular tests Not mandatory for diagnosis of Meniere’s disease
Caloric test is still performed
It is low frequency stimulation (0.003 Hz) of lateral canal
Caloric asymmetry will point to the diseased ear
20% difference between the two ears (Jongkee’s formula) is significant

36. VEMP Vestibular evoked myogenic potential
Measures the relaxation of sternomastoid muscle in response to ipsilateral click stimulus
Brief high intensity ipsilateral clicks produce large short latency inhibitory potentials (VEMP) in the toncially contracted Ipsilateral sternomastoid muscle
This test is due to the presence of vestibulo collic reflex
Afferent arises from sound responsive cells in the saccule, conducted via the inferior vestibular nerve.
Efferent is via vestibulo spinal tract
Normal responses are composed of biphasic (positive-negative) waves
VEMP reveals saccular dysfunction

37. Dehydration tests Glycerol Frusemide Isosorbide
Tests are positive if there is pure tone improvement of 10dB or more at two / more frequencies between Hz

38. Glycerol test First introduced by Klockhoff and Lindblom – 1966
Glycerol is administered in doses of 1.5 mg/kg body wt in empty stomach
Serum osmolality should increase at least by 10 mos/kg
Side effects include Headache, Nausea, vomiting, drowsiness
PTA is performed 2-3 hours after administration
False positivity is rare
Positivity depends on the phase of the disease

39. Medical Management Dietary management Physiotherapy
Psychological support
Pharmacological intervention

40. Treatment of acute exacerbation
Intravenous fluids – dehydration
Vestibular suppressants – May delay recovery / rehabilitation process
Corticosteroids – May help if tinnitus and deafness are debilitating

41. Low salt diet Frustenberg diet
2 grams / 24 hours (restricted salt intake)
Life style modification

42. Role of diuretics
Diuretics play a vital role in alleviating acute symptoms
This has been in use since 1930’s
Thiazide group of drugs are commonly used
Frusemide may be used to alleviate acute symptoms
Clear scientific evidence is lacking regarding the usefulness of diuretics (cochrane review)

43. Betahistine
Cochlear vascular insufficiency has been proposed as one of the mechanism of Meniere's disease
Betahistine is supposed to cause vasodilatation of cochlear blood vessels
Betahistine has weak H1 agonistic property and considerable H3 antagonist properties
It reduces the frequency & intensity of vertigo. Has minimal effect on tinnitus
Doesn’t help much with hearing loss (Cochrane review)

44. Intratympanic steroids
Immune modulating effects
Improves fluid dynamics of inner ear due to mineralocorticoid effects
Vertigo was controlled on an immediate basis
Methylprednisolone has the best effect as it penetrates the round window better
Silverstein microwick can be used for intratympanic drug administration

45. Miscellaneous drugs Isordil ϒ – globulin Urea Glycerol Lithium
Anticholinergics – Glycopyrrolate 1-2 mg /day
Antidopaminergics – Droperidol 2.5 – 10 mg orally / day
Leuprolide acetate – Blocks normal sex hormone production
Innovar – A combination of droperidol and fentanyl can be used to suppress vestibular symptoms (can replace endolymphatic sac surgery)
Hyperbaric oxygen therapy

46. Other treatment modalities (ancillary)
Stress reduction
Patient education
Hearing aids – can be used to suppress troublesome tinnitus
Tinnitus retraining

47. Vibrator therapy Meniett Device Low pressure pulse generator
Vibrations are transmitted via external auditory canal
Vibrations alter inner ear fluid dynamics by their effects on the oval and round windows
Exact mechanism of action is not known
It is totally non invasive
This device is portable

48. Vibrator therapy steps
Diagnosis should be confirmed
Ventilation tube should be inserted
Patient should be trained for self administration of the treatment
Usually administered thrice a day about 5 mins each time
Treatment lasts for 5 weeks

49. Indications for vibrator therapy
Classic unilateral Meniere’s disease
Intense vestibular / cochlear symptoms
Failed medical therapy
Over 65 years of age
Imbalance / aural fullness / tinnitus after gentamycin treatment

50. Contraindications for vibrator therapy
Perilymph fistula
Acoustic neuroma / brain tumor
Retrocochlear damage
Low pressure hydrocephalus

51. Role of aminoglycosides
Vestibulotoxic effects are put to therapeutic use.
Sensation of vertigo reduced while hearing is preserved
Streptomycin / gentamycin are predominantly Vestibulotoxic
Intratympanic administration is preferred

52. Intratympanic gentamycin
Fixed dose protocol is used
40 mg/ml gentamycin is buffered with soda bicarb (pH6.4) final concentration 26.7mg/ml.
T tube grommet inserted into the postero inferior quadrant of ear drum. A mcirocatheter is inserted through the grommet
1ml of gentamycin solution is injected into the middle ear cavity via the microcatheter
Three injections are given per day in outpatient setting
Injections are given for 4 days
After injection patient should lie supine with the infiltrated ear up for 30 mins
Vertigo usually develops between 2-4 days after cessation of treatment

53. Surgical management Sac enhancement procedure
Sac decompression procedure
Labyrinthine ablative procedures

54. Shunt procedure
External shunts – Drains the sac into mastoid cavity / subarachnoid space
Internal shunts – Drains excessive endolymph into the perilymphatic space (cochleosacculotomy / labyrinthotomy)

55. Sac identification

56. Cochleosacculotomy / Labyrinthotomy
Helpful in treating debilitated patients
Involves disruption of osseous spiral lamina
Angular pick introduced via round window towards oval window. It will accommodate 3 mm long pick
After perforation the pick is withdrawn and the round window is sealed by fat

57. Ablative procedures Labyrinthectomy
Translabyrinthine vestibular neurectomy
Retrolabyrinthine vestibular neurinectomy
Retrosigmoid vestibular neurinectomy
Middle cranial fossa vestibular neurinectomy