Meniere's DiseaseDR. GIRISH. S

DEFINITIONA disease of membranous inner ear characterized by

EPISODIC VERTIGO FLUCTUANT SNHL TINNITUS AURAL FULLNESS

Which has its pathologic correlate-

HYDROPIC DISTENSION OF THE ENDOLYMPHATIC SYSTEM

HISTORY

The existence of peripheral vestibular disorders was proposed by Meniere in 1861.

PROSPER MENIERE, as director of a large deaf-mute institution in Paris, saw patients develop both vertigo and deafness immediately after trauma to the ear.

He concluded that both symptoms have a common inner ear origin.

HISTORY MENIERE - Autopsy of a young girl who

developed sudden hearing loss and acute vertigo.

On autopsy, found her brain was normal but the inner ear was filled with blood.

It was commonly believed well into the 20th century that Meniere's disease was caused by hemorrhage.

MENIERE'S DISEASE Prior to 1940,

"Meniere's disease" was used as a generic term for any peripheral vertigo, especially if associated with hearing loss.

HISTORY

In 1926 PORTMAN, believing Meniere’s disease was secondary to Endolymphatic hypertension, performed the first drainage operation of the endolymphatic sac

HISTORY In 1938 Hallpike and Cairns described the

underlying pathology of Meniere’s disease as being endolymphatic hydrops, but the precise etiology still remains elusive.

HISTORY

In 1985 AAO-HNS

updated the term MD should be restrictive and include only those cases with complement of classic symptoms and findings of the disease persumed to result from idiopathic EL hydrops .

ANATOMY OF COCHLEA

Fluid spaces in the cochlea are Perilymphatic space – Scala Vestibuli & Scala

Tympani Endolymphatic space – Scala media

Contd… Perilymphatic space

surrounds the membranous labyrinth and opens to CSF by cochlear aqueduct

The endolymphatic space as well as continuing throughout the membranous labyrinth is joined to the endolymphatic sac by endolymphatic duct

INNER EAR FLUIDS AND THEIR CIRCULATION

ENDOLYMPH Located in the scala media Principally secreted by

STRIA VASCULARIS PLANUM SEMILUNATUM DARK VESTIBULAR CELLS PERILYMPH ACROSS THE MEMBRANOUS LABYRINTH

Low Na+ High K+ There are two views regarding its flow

Longitudinal Radial

LONGITUDINAL PATTERN (slow process) Endolymph from the cochlea reaches saccule,

utricle & ELD and gets absorbed through endolymphatic sac which lies in the subdural space

RADIAL (rapid process) Results from production of endolymph in the dark

vestibular cells and planum semi lunatum with local absorption .

PATHOGENESIS EL hydrops occurs through over production or inadequate

absorption. ENDOLYMPH VEST. AQ. END SAC

OBSTRUCTION

Normal

Hydrops

LONGITUDINAL FLOW.Fundamental problem is ENDOLYMPHATIC MALABSORPTIVE

DYSFUNCTION

HOW THE DYSFUNCTION OCCURS?

Various explanations

Hypoplasia of the vestibular aqueduct

Narrowing of the endolymphatic duct Perisaccular fibrosis Loss of epithelial integrity and

atrophy of the sac Positive immunofluorescent staining

for Igs of the sac wall

Vascular pathology – walls of EL sac in MD shows fewer and small blood vessels than normal

Accumulation of cellular and proteinaceous debri within the sac lumen INFECTIONS

Tightly adherent dura in the region of the endolymphatic sac local sac pressure and resistance to flow malabsorption

ENDOLYMPHATIC MALABSORPTIVE DYSFUNCTION

PATHOLOGIC FINDINGS

A. ENDOLYMPHATIC HYDROPS

B. CHANGES IN PARS SUPERIOR

C. CHANGES IN HAIR CELLS

ENDOLYMPHATIC HYDROPS Physical distortion of the membraneous labyrinth.

Most consistently

found in the PARS

INFERIOR (cochlea

and saccule).

ENDOLYMPHATIC HYDROPS It is typified by bowing

of Reissner’s membrane into the scala vestibuli and the distention of the saccule

Enlargement of EL space occur at the expense of perilymphatic space.

ENDOLYMPHATIC HYDROPS Degree of endolymphatic space expansion is

variable

Endolymphatic space bulged in the region of helicotrema in 50% of cases

Saccule bulges against foot plate in 60%

Saccule bulges into SCC (in 1/3 cases)

CHANGES IN THE PARS SUPERIORUTRICLE AND SEMICIRCULAR CANALS

Less frequent Utricular dilatation and

herniation into crus commune Ampullary distorsion and

displacement of cupulae from the ampullary wall

Hair cells, along with the innervating nerves are spared.

Only in most severe cases –decrease in hair cells.

CHANGES IN HAIR CELLS

EM - fusion of cilia, disruption of cuticular bodies & basalward displacement of some OHC with loss of contact with cuticular plate .

THEORIES REGARDING GENESIS OF SYMPTOMS

I. MEMBRANE RUPTURE THEORY

Ruptures in the membranous labyrinth pathophysiology of MD.

Found in nearly all parts of the inner ear

RUPTURE

Leakage of this neurotoxic endolymph into the

perilymph

Sustained depolarization

Inactivation of the hair cells and neurons of the 8th

nerve

• Subsequent healing return of normal inner ear

function and resolution of the symptoms of

Meniere’s attack

• C/c exposure progressive irreversible

deterioration of the auditory and vestibular

functions

PHASES OF ATTACK IRRITATIVE PHASE- Increased K+ around the basal

surface of hair cells activation of vestibular nuclei PARETIC PHASE- Prolonged activation blockade of

NT release peripheral hypofunction decreased activity of vestibular nucleus

RECOVERY PHASE- Restitution of chemical composition

II. High endolymphatic pressure

Causes cochlear damage and hearing loss in MD TONNDORF – suggested mechanical distorsion and

tension in the membrane of inner ear

III. Saccular hydrops

Severe cases extend into the SCC and alter function of crista ampullaris vertigo.

Presence of such distension can also explain the positional vertigo in patients with MD

IV. Mechanical factors

Tonndorf (1968) Hydrops can mechanically alter the travelling

waves

explain certain aspects of cochlear dysfunction.

PATHOGENESIS

Excess production of endolymph

Poor absorption ofendolymph

Endolymphatic hydrops

Distension of scala media, saccule and

endolymphatic duct with marked bulging

of Riessner’s membraneRupture of Riessner’s membrane

Capillary sludging/ low perfusion

Anoxia of stria vascularis

Transudation of fluid

STRESS

Sympathetic overactivity

Internal auditory artery spasm

Inadequate vascularity of sac

Damage to neuroepithelium

Obstruction to flow

Contd…..Mixture of endo & perilymph

Increase in K+ level in perilymph

ACUTE EFFECTS Aural fullness Vertigo Temporary SN loss

CHRONIC EFFECTS Residual hearing

loss Tinnitus

CONSTITUTIONAL SECONDARY FACTORS

Meniere’s diseaseVascular

MetabolicHypothyroidism’

InfectiousSyphilis, Mumps, Herpes infection,CSOM

Allergic50% associationInner ear acting as shock organ

Psychogenicpsychological vulnarability and obscession

NeurogenicCogan’s syndrome(Hearing loss vertigo

AutoimmuneCONTRALATERAL DELAYED HYDROPS- development of Abs to inner ear antigens

Genetic (chr 6)

TERMS The triad of hearing loss, tinnitus and vertigo constitute

MENIERE’S SYNDROME If cause is unknown it is defined as MENIERE’S DISEASE. However, if a disease entity that is known to cause

endolymphatic hydrops is associated with the syndrome, the diagnosis is one of SECONDARY ENDOLYMPHATIC HYDROPS

MENIERE’S DISEASE GENETIC ANATOMICAL TRAUMATIC VIRAL INFECTION ALLERGY AUTOIMMUNITY PSYCHOSOMATIC AND PERSONALITY FEATURES

GENETIC FACTORS

Familial tendency 14-20% AD transmission Sporadic and familial cases of MD HLA-C and

HLA-A on short arm of chromosome-6 Mutation predispose to MD

ANATOMICAL Small vestibular aqueduct

TRAUMATIC Physical or acoustic trauma Trauma

Biochemical dysfunction of cells in memb labyrinth or

Simply release debri into the endolymph obstruct ELD and sac

VIRAL INFECTION Neurotropic virus Higher antibody reactivity to Herpes simplex type

I Polypeptides Herpes simplex viral DNA in ELS tissue

ALLERGY

Proposed etiologic factors

Both food and inhalants allergy

AUTOIMMUNITY

The ELS contain Ig and lymphocytes capable of generating humoral or cellular immune response

Circulating immune complexes in the serum direct cause of damage

Antibodies Vs Type II collagen found in serum of MD patients

PSYCHOSOMATIC AND PERSONALITY FACTORS

A basic disorder of personality occur in MD Emotion acts as a precipitating factor Most have an elevated obsessionality score Psychic stress in childhood Overt neurosis

MORE COMMON

SECONDARY EL HYDROPS Developmental insults ABNL metabolic and endocrine status Syphilis C/c OM Viral infection Autoimmunity Otosclerosis Leukemia

Etiological factors in 20 ELH Developmental insults like Mondini Dysplasia Abnormal metabolic and endocrine status

Metabolic states – hypoglycemia, hyperglycemia and hyperlipoproteinemia

Endocrinological associations

Hypothyroidism Adrenal pituitary insufficiency symptoms in females during premenstrual period

SYPHILIS Known cause of ELH &

Meniere’s triad of symptoms

Syphilitic osteitis of the otic capsule

Syphilitic endolymphatic

duct obstruction

Progressive over accumulation of endolymph and

subsequent rupture

C/c Otitis Media Infectious products, toxins and associated

enzymes migrating through the RW membrane in to fluids of inner ear

Osteitis from mastoiditis can affect adjacent developing sac and blood supply in Trautman’s triangle

VIRAL INFECTION as a delayed sequelae during attacks of

subclinical viral labyrinthitis

OTOSCLEROSIS When envelops vestibular aqueduct malfunction of the

ELD and sac

Otosclerosis can invade the endosteum, altering chemical characteristics of perilymph and endolymph and thus affect radial and longitudinal flow of endolymph

SYMPTOMS

Characteristics of vertigoSYMPTOMS Sudden onset Preceded by aural

fullness Feeling of to and fro

or up and down movement- Ship wrecked in storm feeling

Episodic- lasting from 20 mins to 24 hrs

Associated vomiting, anxiety

Tullio phenomenon Tumarkin drop

attacks

SIGNS Nystagmus - depending

on phase Associated

Documentable hearing loss

Spontaneous complete recovery

Absence of loss of consciousness, neurological deficits, persistant imbalance after the episode

Vertigo in Meniere’s disease IRRITATIVE PHASE- activation of vestibular nuclei

Nystagmus on same side of lesion PARETIC PHASE- blockade of NT release decreased

activity of vestibular nucleus Nystagmus on opposite side (As neuronal activity in normal side is relatively more)

RECOVERY PHASE- Restitution of chemical composition-Recovery of peripheral vestibular function after remission

Acute attacks of MD – rarely seen

Horizontal nystagmus is the cardinal finding Irritative nystagmus – towards affected ear Paralytic nystagmus – towards the normal ear Hours after attack, auditory and vestibular

symptoms subsides and nystagmus reversed towards the affected ear – recovery nystagmus

TUMARKIN CRISIS DROP ATTACKS in later stages. Occur as a result of Acute Otolithic Dysfunction Pt simply drops to the ground without warning

& can sustain # / other serious injury. There is no associated vertigo / loss of

consciousness

Existence of an EL hydrops with contact of the

saccular wall up to the internal face of the

footplate. (internal sacculostapedopexy).

This also explains the TULLIO PHENOMENON

HENNEBERT’S SIGN

HEARING LOSS

Repeated pressure trauma

Direct damage due to poor vascularityDamage to vestibular and

cochlear neuroepithelial cells

Hearing loss(lower frequencies affected first)

Clinical features

SYMPTOMS Fluctuating hearing loss More during the episode of

vertigo DYPLAUCUSIS - distorted

appearance of music Intolerability to loud sound

SIGNS Tuning fork tests s/o SNHL

PTA – low freq HL

SDS - 55-85%

Recruitment test - positive

SISI test score- >70%

Tone decay test < 20dB

SP/ AP >30%

Caloric test decreased response on affected side

Oral glycerol test

SNHL Typically fluctuant and progressive Over time, the hearing loss flattens and becomes

less variable 5-10 YEARS

SNHL

A pattern of low frequency fluctuating loss and a coincident, non changing, high frequency loss is described, a

“PEAKED” OR “TENT LIKE” AUDIOGRAM This peak classically occurs at 2KHz .

TINNITUS Subjective tinnitus Low pitched and roaring May even persist during the periods of

remissions Continuous or intermittent

TINNITUS Non pulsatile Tinnitus often begins, gets louder, or

changes pitch as an attack approaches

Later tinnitus is constant and more distracting between attacks

Mechanism of tinnitus+K Ion intoxication of outer hair cells

Contraction of outer hair cells

Tectorial membrane irritates the steriocilia of the inner hair cells

Generation of abnormal spontaneous desynchronised impulses in inner hair cells (summating potential)

TINNITUS

AAO-HNS 1995

POSSIBLE MENIERE'S DISEASE Episodic vertigo of the Meniere's type

without documented hearing loss, or

SNHL , fluctuating or fixed, with dysequilibrium but without definitive episodes

Other causes excluded

AAO-HNS 1995

PROBABLE MENIERE'S DISEASE One definitive episode of vertigo

Audiometrically documented hearing loss on at least one occasion

Tinnitus or aural fullness in the treated ear

Other causes excluded 

AAO-HNS 1995 DEFINITE MENIERE'S DISEASE

Two or more definitive spontaneous episodes of vertigo 20 minutes or longer

Audiometrically documented hearing loss on at least one occasion

Tinnitus or aural fullness in the treated ear

Other cases excluded 

CERTAIN MENIERE'S DISEASE Definite Meniere's disease, plus

histopathologic confirmation

Stage PTA

1 <=25

2 26-40

3 41-70

4 >70

EXAMINATION & INVESTIGATIONS

Romberg test significant instability and worsening

when the eyes are closed.

Weber tuning fork test lateralizes away from the

affected ear.

Rinne test positive.

ABC reduced .

Physical Examination

MRI • Rule out abnormal anatomy or mass lesions. • Acoustic neuromas, other CPA lesions.• MS or Arnold-Chiari malformations

CT scans• Dehiscent superior semicircular canals • Widened cochlear and vestibular aqueducts

IMAGING STUDIES

OTHER TESTS PTA SPEECH AUDIOMETRY SPECIAL AUDIOMETRY TESTS ENG ECoG CALORIC TESTS GLYCEROL TEST

Low-frequency or mixed low and high-frequency

insufficiency may be observed.

Typically, the lower frequencies are affected

more severely. This is due to preferential sensitivity of

the apex to the hydrops.

PTA

SPEECH AUDIOMETRY Discrimination score is usually 55 – 85% between the

attacks.

But it is much impaired during and immediately

following an attack.

SPECIAL AUDIOMETRY TESTS

RECRUITMENT TEST POSITIVE

SISI SCORE better than 70% in 2/3rds of

patients.

TONE DECAY TEST normally there is decay

of less than 20dB.

LOUDNESS RECRUITMENT

1. This is abnormal growth in the perceived intensity of sound

2. ABLB

3. This test is really time consuming

Detects distortion of the neural membranes of the

inner ear.

Due to perilymph pressure fluctuations and can show

evidence of cochlear involvement.

Ratio of the SP and the nerve AP in response to

auditory stimuli.

ELECTRO COCHLEOGRAPHY

ELECTRO COCHLEOGRAPHY1. 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

Typically causes a reduced vestibular response in the

affected ear

The direction of the spontaneous nystagmus during or

after an attack of Meniere is not a reliable indicator of the

site of the lesion.

ELECTRONYSTAGMOGRAPHY (ENG)

VESTIBULAR TESTS

1. Caloric test

2. It is low frequency stimulation (0.003 Hz) of lateral canal

3. Caloric asymmetry will point to the diseased ear

4. 20% difference between the two ears ( JONGKEE’S FORMULA ) is significant

VEMP

Measures the relaxation of sternomastoid muscle in response to ipsilateral click stimulus

This test is due to the presence of vestibulo collic reflex

Normal responses are composed of biphasic (positive-negative) waves

VEMP reveals saccular dysfunction

DEHYDRATION TESTS

1. GLYCEROL

2. FRUSEMIDE

3. ISOSORBIDE

4. UREA

5. SORBITOL

Tests are positive if there is pure tone improvement of 10dB or more at two / more frequencies between 200-2000Hz

One of the most important & commonly used

diagnostic test

Glycerol is administered orally in doses of 1.5

mg/kg in the fasting state

GLYCEROL DEHYDRATION TEST

Test is only considered positive if there is an

increase in serum osmolality of 10 mos/kg.

PTA is performed 2-3 hours after administration

A rise in threshold of at least 10db in three

consecutive octave bands were considered

diagnostic of Meniere’s disease.

GLYCEROL DEHYDRATION TEST

MANAGEMENT NON INTERVENTIONAL TREATMENT

LIFE STYLE MODIFICATIONS MEDICAL MANAGEMENT REHABILITATION

INTERVENTIONAL TREATMENT NON DESTRUCTIVE SURGICAL PROCEDURES DESTRUCTIVE SURGICAL PROCEDURES

GENERAL MEASURES REASSUARANCE CESSATION OF SMOKING (nicotine vasospasm) LOW SALT DIET AVOID EXCESS INTAKE OF WATER AVOID OVER-INDULGENCE IN COFFEE,TEA,ALCOHOL AVOID ACTIVITIES REQUIRING GOOD BODY BALANCE AVOID STRESS

ACUTE ATTACKSevere vertigo n nausea, apprehensive, head movts -> giddiness REASSUARANCE BED REST VESTIBULAR SEDATIVES

Oral/ im / iv Prochlorperazine / Promethazine Diazepam / Atropine

VASODILATORS Inhalation of Carbogen Histamine drip

VASODILATORS INHALATION OF CARBOGEN

5% CO2 + 95% O2

cerebral vasodilator, improves labyrinthine circulation

HISTAMINE DRIP Histamine diphosphate, 2.75 mg dissolved in 500

ml of glucose, given as iv drip at a slow rate good vasodilator and helps to control acute

attacks.

CHRONIC PHASE VESTIBULAR SEDATIVES VASODILATORS DIURETICS PROPANTHALINE BROMIDE ELIMINATION OF ALLERGEN HORMONES

SURGICAL TREATMENTSUsed only when medical treatment fails

SURGICAL OPTIONS Aims to achieve one or both of the two possible goals.

1. ABOLISH OR ALTER FUNCTION OF THE LABYRINTH may cause vertigo until vestibular compensation

has re-established symmetric, resting neural activity in the central pathways.

also carry the risk of hearing loss.

SURGICAL OPTIONS2. MODIFICATION OF THE UNDERLYING PATHOPHYSIOLOGY.

harder to achieve since the underlying physiology is still not well understood

SURGICAL OPTIONS

1. NONABALTIVE PROCEDURES

2. PARTIALLY ABLATIVE PROCEDURES

3. LOCAL OVERPRESSURE THERAPY

4. ENDOLYMPHIC DECOMPRESSION

5. VESTIBULAR NEURECTOMY

6. LABYRINTHECTOMY

INTRATYMPANIC DELIVERY TECHNIQUES

Direct injection through the tympanic membrane.

Injection through an inserted ventilation tube. Injection through an indwelling catheter

inserted into the middle ear. Placing a sponge through the tympanic

membrane. Injection directly into the round window niche. Minipumps.

INTRATYMPANIC DRUG DELIVERY

Direct intratympanic injection can be done in the office and is probably the easiest method.

Prior to injection, the tympanic membrane should be anesthetized.

Topical Phenol Applied Injection Of The External Auditory Canal With Lidocaine Topical Emla™ Cream (Lidocaine 2.5%, Prilocaine 2.5%)

25-gauge needle superior port to allow air to exit the middle ear and an inferior port for injection.

The middle ear generally holds 0.5 to 0.8 mL of fluid.

A brief episode of vertigo typically follows the injection

Patient should lie in a slight Trendelenberg position with the treated ear up for 30 min

INTRATYMPANIC DRUG DELIVERY

NONABALTIVE PROCEDURESINTRATYMPANIC INJECTION OF CORTICOSTEROID Corticosteroids have an anti-inflammatory effect

on the labyrinth in conditions of likely immune origin.

Steroids have been shown to influence ion transport in the labyrinth.

More helpful in the early stages of MD

INTRATYMPANIC INJECTION OF CORTICOSTEROID

Dexamethasone is now a standard therapy Repeat injections are frequently required for

recurrent symptoms. Repeat dosing at 3 months is a reasonable starting

point. Concentrations used have varied from 2 to 24

mg/mL. The risk of hearing loss is low.

PARTIALLY ABLATIVE PROCEDURES INTRATYMANIC INJECTION OF GENTAMYCIN

Gentamicin has a high vestibulotoxicity relative to its cochleotoxicity; thus, it can be used to control vestibular symptoms while sparing hearing.

Current trend single injection regimen, with additional doses only if needed to control symptoms ("titration therapy").

PARTIALLY ABLATIVE PROCEDURES GENTAMICIN diffusion through the RW

Access maybe impaired by inflammation causing

increased membrane thickness, or obstruction with fat

or fibrous tissue.

When gentamicin reaches the endolymph, it is

selectively concentrated in hair cells and supporting

cells.

Aminoglycosides destroy hair cell function by a variety of mechanisms.

They block ion currents through the stereocilia, cause adhesion of stereocilia, and ultimately, cause the hair cells to degenerate or become extruded.

Gentamicin has a greater effect on type I than on type II hair cells.

PARTIALLY ABLATIVE PROCEDURES

TRANSTYMPANIC GENTAMYCIN

Gentamycin (4mg/ml)

buffered with NaHCO3 until

pH is 6.4

Through T tube 1ml

3 injections/ day

(7am-1pm-7pm)

Lies half hour supine

with ear facing up.

LOCAL OVERPRESSURE THERAPY

Application of external pressure to the middle ear to encourage endolymphatic flow into the EL sac.

Increased endolymph pressure facilitates absorption.

MENIETT DEVICE

MENIETT DEVICE The device is a handheld air pressure generator that

the patient self-administers three times daily. The pressure is delivered in complex pulses of up to

20 cm of water over a 5-min period. The device requires ventilation tube placement in

the tympanic membrane prior to starting therapy.

ENDOLYMPHIC DECOMPRESSION

Benefits include Release of external compression on the sac Neovascularization of the perisaccular

region, allowing passive diffusion of endolymph

Creation of an osmotic gradient out of the sac

INTERNAL SHUNTS FICK ’S SACCULOTOMY CODY TACK OPERATION COCHLEOSACCULOTOMY OF SCHUKNECHT

( LABYRINTHOTOMY ) OTIC PERIOTIC SHUNT OF HOUSE & PULEC

OLD TECHNIQUES

OLD TECHNIQUES

SACCULOTOMY WAS PROPOSED BY FICK in 1964 and consisted of using a needle to puncture the saccule through the stapes footplate.

CODY TACK OPERATION Leaving a sharp prosthesis in the footplate that ruptured the saccule each time it expanded.

OLD TECHNIQUES

The OTIC-PERIOTIC SHUNT is a tube placed through the round window membrane that perforates the basilar membrane.

COCHLEOSACCULOTOMY aims to create a fracture

dislocation of the osseous

spiral lamina

(permanent fistulization of the

endolymph-containing cochlear

duct)

VARIATIONS IN EL SAC SURGERY

Simple decompression Wide decompression including the sigmoid sinus Cannulation of the endolymphatic duct EL drainage to the subarachnoid space EL drainage to the mastoid Removal of the extraosseus portion of the sac

ENDOLYMPHATIC SAC SURGERY

Simple mastoidectomy Horizontal and posterior canals

should be skeletonized and the bone over the posterior fossa thinned .

Only a thin covering of bone should be left over the facial nerve and the sigmoid sinus to allow adequate exposure of the posterior fossa dura.

The bone over the posterior fossa should be completely removed using a diamond burr .

The EL sac lies on the dura medial to the vertical segment of the facial nerve and the retrofacial air cells.

The superior aspect of the EL sac should be identified, and often lies just below a line (Donaldson's line)

Decompression of the sac requires only that the bone of the posterior fossa plate be removed.

EL SHUNTING EXTERNAL SHUNTS ( mastoid / subarachnoid )

EL SHUNTING Performed by incising the exposed sac and placing

a stent to keep the incision open. PAPARELLA AND HANSON TECHNIQUE involves

opening the edge of the sac, lysing any intraluminal adhesions, and probing the duct to insure that it is patent.

A piece of SILASTIC is placed through the incision in the sac allowing long-term drainage.

DRAINAGE TO SUBARACHNOID SPACE

More elaborate since it requires making a second incision in the posterior wall of the EL sac into the posterior fossa and a specially designed shunt tube.

DRAINAGE TO SUBARACHNOID SPACE

After the initial, lateral incision is made in the sac, a small medial incision is made to allow a shunt to be placed into the basal cistern creating a passage into the subarachnoid space .

The resulting CSF leak is controlled by placing a fascia graft over the lateral incision in the sac.

Patients can usually return to work within a week.

Although the procedure is intended to be a hearing-sparing procedure with minimal morbidity, the risk of hearing loss may be as high as 5%.

A small risk of facial nerve damage associated with the procedure.

Vestibular nerve section has a complete vertigo control rate of about 85 to 95%

80 to 90% of patients maintain their preoperative hearing.

The procedure offers much greater vertigo control rates than EL shunt procedures.

More invasive. Technically challenging procedure.

VESTIBULAR NEURECTOMY

VESTIBULAR NEURECTOMY APPROACHES TO VESTIBULAR NERVE

RETROSIGMOID / SUBOCCIPETAL MIDDLE CRANIAL FOSSA RETROLABYRINTHINE TRANSMEATAL COCHLEOVESTIBULAR

NEURECTOMY

RETROSIGMOID APPROACH Advantage of a generous exposure and a direct

view of the seventh and eighth cranial nerves. Standard suboccipital craniotomy having the

sigmoid sinus as the anterior limit of exposure. The posterior fossa dura is opened, and the

cerebellum is retracted to expose the cerebellopontine angle and petrous ridge.

The vestibular, cochlear, and facial nerves are identified, and then the superior and inferior vestibular nerves can be sectioned.

Afterward the dura is reapproximated, and the bone flap is replaced and covered as the wound is closed.

RETROSIGMOID APPROACH

MIDDLE FOSSA APPROACH Advantage - require only minimal dural violation. A vertical incision is made above the auricle and the

temporalis muscle is freed from squamous portion of the temporal bone.

A small craniotomy is made in the squamous portion of the temporal bone.

The middle fossa dura is elevated and a Fisch or House-Urban retractor is used to maintain temporal lobe elevation.

The superior SCC and geniculate ganglion are identified on the floor of the middle fossa as landmarks.

IAC is unroofed using a diamond burr. The dissection is carried out to the lateral extent

of the canal to identify "Bill's bar," which divides the facial nerve from the superior vestibular nerve.

MIDDLE FOSSA APPROACH

The dura of the posterior aspect of the canal is incised and the superior vestibular nerve is identified.

As the superior vestibular nerve is retracted, the inferior vestibular nerve can be identified, taking care to avoid the internal auditory artery and cochlear nerve.

MIDDLE FOSSA APPROACH

Often it is difficult to definitively separate the inferior vestibular nerve from the cochlear nerve, which can lead to remaining vestibular symptoms after surgery or hearing loss.

Upon nerve sectioning, the internal auditory canal can be covered with fascia, the bone flap replaced, and the incision closed.

MIDDLE FOSSA APPROACH

LABYRINTHECTOMY most destructive procedure in the treatment of

Meniere's as it destroys both hearing and vestibular

function.

Ideal candidates are those who have no hearing and

have failed more conservative treatments

Higher rate of vertigo control than vestibular

neurectomy and improves quality of life in 98% of

patients.

APPROACHES

LEMPERT’S TRANSCANAL

TRANSMASTOID (better exposure / more

popular )

LABYRINTHECTOMY

LEMPERT’S TRANSCANAL LABYRINTHECTOMY

Posterior annulus curetted for exposure

Ampullary ends of SCC probed to ensure destruction of neuroepithelium.

TRANSCANAL APPROACH

A variation on this basic technique involves drilling out the promontory to connect the OW and RW.

Posterior ampullary nerve is sectioned

Vestibule filled with absorbable gelatin sponge/fat graft

The limitation is the poor access it yields to the posterior canal, located medial to the facial nerve; thus, complete ablation may not be achieved.

The limited exposure also makes the procedure more technically difficult than the transmastoid approach.

TRANSCANAL APPROACH

TRANSMASTOID APPROACH Advantage of allowing direct visualization of the vestibular

end organs as they are removed. Standard mastoidectomy Identification of the SCC. The canals can then be blue-lined and followed medially to

the vestibule while removing the neuroepithelium under direct vision.

Complete loss of hearing is an expected

outcome.

Can preserve hearing by packing the SCC with

bone wax & using a diamond burr to remove the

canal while preserving the vestibule.

LABYRINTHECTOMY

REHABILITATION

HEARING AIDS

VESTIBULAR REHABILITATION

For patients who responded to medical or

surgical treatment for vertigo but have

some remaining disequilibrium.

THANK YOU…!