Ménière's Disease: Differential Diagnosis & Surgical Management

(50-Mark RGUHS Long Essay)

INTRODUCTION

1. Episodic spontaneous vertigo (lasting 20 minutes to several hours)
2. Fluctuating sensorineural hearing loss (usually low-frequency)
3. Tinnitus (usually low-pitched, roaring)
4. Aural fullness/pressure

PART I: DIAGNOSTIC CRITERIA

PART II: DIFFERENTIAL DIAGNOSIS OF MÉNIÈRE'S DISEASE

🔷 FLOWCHART 1: APPROACH TO DIFFERENTIAL DIAGNOSIS

                    PATIENT PRESENTS WITH
                    EPISODIC VERTIGO + HEARING LOSS
                             |
              _______________↓_______________
             |                               |
     ASSOCIATED WITH                  NOT ASSOCIATED WITH
     HEARING CHANGE?                  HEARING CHANGE?
             |                               |
     _______YES_______                       ↓
    |                 |              Consider BPPV, Vestibular
 Fluctuating?     Fixed/stable?     Neuritis, Migraine-assoc.
    |                 |             Vertigo, Central causes
MÉNIÈRE'S         Acoustic
    DD             Neuroma/
                   SNHL
             |
   ___________↓______________
  |        |        |        |
AIED    Syphilis  Trauma  Migraine
                           Vestibulopathy

A. VESTIBULAR MIGRAINE (Migraine-Associated Vertigo)

• Most important differential; accounts for up to 30% of episodic vertigo cases
• Vertigo episodes can last minutes to hours (overlap with MD)
• Key differences from MD:
  • Headache, photophobia, phonophobia often present
  • No progressive SNHL or audiometric changes
  • Normal electrocochleography (ECoG)
  • Positive personal/family history of migraine
  • Episodes often triggered by hormonal changes, stress, dietary triggers
• Responds to migraine prophylaxis (beta-blockers, topiramate)

B. BENIGN PAROXYSMAL POSITIONAL VERTIGO (BPPV)

• Most common cause of recurrent vertigo overall
• Key differences:
  • Vertigo lasts < 1 minute (versus 20 min–hours in MD)
  • Provoked by head position change; not spontaneous
  • Positive Dix-Hallpike test with rotatory nystagmus (5–10 second latency, 10–30 second duration)
  • No hearing loss, tinnitus, or aural fullness
  • Canalith repositioning (Epley maneuver) effective in 74–91%
• Secondary to posterior semicircular canal debris (canalolithiasis)

C. VESTIBULAR NEURITIS (Vestibular Neuronitis)

• Single prolonged episode of severe vertigo lasting days; no recurrence in the MD pattern
• Caused by neurotropic virus (herpes simplex most common); Borrelia also implicated
• Key differences:
  • No hearing loss (pure vestibular, usually superior vestibular nerve)
  • No tinnitus or aural fullness
  • Positive Head Impulse Test (catch-up saccade)
  • Canal paresis on caloric testing
  • Does NOT recur episodically
• Treatment: supportive, vestibular rehabilitation; role of steroids controversial
• Pathology: Superior vestibular nerve more commonly involved due to longer, narrower bony canal

D. ACOUSTIC NEUROMA (VESTIBULAR SCHWANNOMA)

• Unilateral SNHL, tinnitus, imbalance (but vertigo usually NOT episodic/violent)
• Key differences:
  • Progressive unilateral SNHL with poor speech discrimination (disproportionate)
  • Absent acoustic reflex
  • Vertigo is chronic disequilibrium, not episodic
  • MRI with gadolinium — diagnostic gold standard (mass in internal auditory canal/CPA)
  • ABR: prolonged Wave V latency, interaural difference > 0.2 ms
• Must always be excluded before diagnosing MD

E. AUTOIMMUNE INNER EAR DISEASE (AIED)

• Bilateral rapidly progressive SNHL (weeks to months)
• Fluctuating hearing loss mimicking MD
• Key differences:
  • Bilateral involvement (MD starts unilateral)
  • Associated systemic autoimmune disease (SLE, RA, Cogan's syndrome)
  • Elevated inflammatory markers (ESR, CRP, ANA, Anti-68 kDa antibody)
  • Responds to steroids (both hearing and vestibular symptoms)
  • Electrocochleography may be normal
• K.J. Lee notes AIED in the differential for MD

F. SYPHILITIC (LUETIC) LABYRINTHITIS

• Tertiary syphilis: bilateral fluctuating SNHL, episodic vertigo mimicking MD
• Key differences:
  • Bilateral; involvement of both ears more common and earlier
  • Interstitial keratitis, saddle nose deformity, positive FTA-ABS (even VDRL may be negative)
  • Hennebert's sign (positive fistula test with intact TM) — pathognomonic of luetic disease
  • Responds to penicillin + steroids
• Always exclude with FTA-ABS serology

G. PERILYMPHATIC FISTULA (PLF)

• Abnormal communication between perilymph space and middle ear
• Key differences:
  • History of barotrauma, straining, head injury
  • Vertigo and SNHL provoked by Valsalva or loud noise (Tullio phenomenon)
  • Fistula test positive
  • Site: around stapes footplate and round window
  • Diagnosis by exploratory tympanotomy
• Initial treatment: bed rest, stool softeners; surgery: closure of fistula with fascia

H. DELAYED ENDOLYMPHATIC HYDROPS

• Profound SNHL in one ear (from prior infection/trauma) → years later symptoms of hydrops develop
• Can be ipsilateral (same ear as original loss) or contralateral
• Represents secondary hydrops rather than idiopathic
• Distinguish by history of prior unilateral deafness

I. SUPERIOR SEMICIRCULAR CANAL DEHISCENCE (SSCD)

• Tullio phenomenon (sound-induced vertigo) + autophony
• Conductive hearing loss with normal tympanometry
• CT temporal bones: dehiscence of superior canal
• Pressure- and sound-induced nystagmus

J. CENTRAL CAUSES (MUST NOT MISS)

🔷 SUMMARY TABLE: KEY DIFFERENTIATING FEATURES

PART III: SURGICAL MANAGEMENT OF MÉNIÈRE'S DISEASE

PRINCIPLES

"Only in persistent incapacitating vertigo which has failed medical management is surgical intervention considered." — K.J. Lee's Essential Otolaryngology

1. Control of vertigo (primary)
2. Preservation of hearing (if serviceable)
3. Prevention of disease progression

🔷 FLOWCHART 2: SURGICAL DECISION ALGORITHM FOR MÉNIÈRE'S DISEASE

         MÉNIÈRE'S DISEASE
         REFRACTORY TO MEDICAL Rx
                  |
       ___________↓____________
      |                        |
 SERVICEABLE              NON-SERVICEABLE
 HEARING                  HEARING (affected ear)
      |                        |
      ↓                        ↓
 Consider hearing-        LABYRINTHECTOMY
 preserving procedures    (Chemical or Surgical)
      |
 _____|_______________
|            |        |
↓            ↓        ↓
ELS         IT       VESTIBULAR
Surgery  Gentamicin  NEURECTOMY
(sac     (ablative   (hearing
decomp)  chemical    preserving,
         labyrinth)  definitive)
      |
   Bilateral
   disease?
      |
      ↓
   Avoid ablative
   procedures;
   prefer ELS or
   Meniett device

CLASSIFICATION OF SURGICAL PROCEDURES

SURGICAL PROCEDURES FOR MÉNIÈRE'S DISEASE
│
├── A. CONSERVATIVE (Hearing-Preserving, Non-Ablative)
│   ├── 1. Endolymphatic Sac Surgery
│   │   ├── a. Endolymphatic Sac Decompression (ESD)
│   │   └── b. Endolymphatic Sac Shunt (ESS)
│   │       ├── Mastoid shunt
│   │       └── Subarachnoid shunt
│   └── 2. Meniett Device / Pressure therapy (non-surgical)
│
├── B. SEMI-DESTRUCTIVE (Ablative, Hearing-Preserving possible)
│   └── 3. Intratympanic Gentamicin (Chemical Labyrinthectomy)
│
└── C. DESTRUCTIVE (Ablative)
    ├── 4. Labyrinthectomy
    │   ├── Transcanal / Transmastoid
    │   └── Chemical (IT Gentamicin high dose)
    └── 5. Vestibular Neurectomy
        ├── Middle Cranial Fossa approach
        ├── Retrosigmoid / Posterior fossa approach
        └── Translabyrinthine approach (sacrifices hearing)

1. ENDOLYMPHATIC SAC SURGERY (ELS)

Rationale

Anatomy of the Endolymphatic Sac

• Located in the posterior cranial fossa, between the layers of the dura, along the posterior face of the petrous pyramid
• Accessed via a cortical mastoidectomy with identification of the posterior fossa dural plate and sigmoid sinus
• The sac lies in the Trautmann's triangle — bounded by sigmoid sinus posteriorly, bony labyrinth anteriorly, and superior petrosal sinus superiorly

Procedure: Endolymphatic Sac Decompression

1. Postauricular incision; cortical mastoidectomy
2. Skeletonize the sigmoid sinus and posterior fossa dural plate
3. Remove bone over the posterior fossa dura in the retrofacial air cell area (Trautmann's triangle)
4. Identify the endolymphatic sac — appears as a white, thickened area of dura between the sigmoid sinus and the posterior semicircular canal
5. Wide bony decompression of the dura overlying the sac (Graham-Kemink technique — wide bony decompression of the posterior fossa dura)
6. The sac is left intact (decompression) OR
7. The sac is opened and a silastic tube is inserted into the mastoid cavity (mastoid shunt)

• Vertigo control: 60–75% success; drops to ~50% at 5 years
• Hearing preservation: good (only 1–3% risk of SNHL)
• Controversial: randomized studies comparing ESD with mastoidectomy alone (Thomsen, 1981; Bretlau, 1984) showed no significant difference — "the Placebo effect in surgery for Ménière's disease"
• Blinded randomized studies failed to show significant differences in hearing maintenance or vertigo control between ELS and mastoidectomy alone

Subarachnoid Shunt

• More aggressive: endolymphatic duct is opened and a tube drains into the subarachnoid space (CSF)
• Higher risk of CSF leak and meningitis; largely abandoned

2. INTRATYMPANIC GENTAMICIN (CHEMICAL LABYRINTHECTOMY)

Rationale

Mechanism

• Aminoglycoside enters via round window membrane → taken up by type I vestibular hair cells → irreversible hair cell destruction → vestibular deafferentation → central compensation occurs → vertigo controlled

Protocol (K.J. Lee)

• 3/4 cc gentamicin 40 mg/mL + 1/4 cc bicarbonate 0.6M
• Injected into the middle ear (through tympanic membrane or myringotomy)
• 2–6 treatments

Results

• Vertigo control: 85–90% success rate
• Risk of SNHL: up to 20% with multiple doses
• Restrict to unilateral disease — bilateral use risks bilateral vestibular failure (oscillopsia, ataxia, chronic disequilibrium)
• Increasingly preferred over ELS due to office-based administration

Selected IT Steroid Protocols (Dexamethasone — Hearing-Preserving)

• Dexamethasone IT: used when hearing preservation is paramount
• First described by Itoh and Sakata (1987): 4–5 weekly injections of 2 mg dexamethasone
• Results: vertigo relief in 80%, tinnitus reduction in 74%
• Randomized controlled trial (Garduño-Anaya): significant improvement in vertigo; no significant change in PTA or THI
• Dexamethasone preferred over methylprednisolone for middle ear tolerance despite lower perilymph concentrations

3. LABYRINTHECTOMY

Indications

• Non-serviceable hearing in the affected ear (speech discrimination < 50% or PTA > 50 dB)
• Unilateral disease
• Failed other interventions
• Patient preference for definitive control

Types

• Steps:
  1. EUA + myringotomy, removal of tympanic membrane (flap)
  2. Removal of stapes and incudostapedial joint
  3. Opening the oval window widely
  4. Using picks and suction to remove all membranous labyrinthine contents (utricle, saccule, semicircular canal ampullae)
  5. Pack with absorbable material
• Simple, office/outpatient procedure

• Cortical mastoidectomy → identify all three semicircular canals
• Open all canals → remove membranous contents → ablate the utricle and saccule
• More complete than transcanal approach

• Vertigo control: 85% success
• Hearing: completely destroyed in the operated ear
• Enables central compensation over 6–12 weeks

4. VESTIBULAR NEURECTOMY

Rationale

Indications

• Unilateral Ménière's disease
• Serviceable hearing bilaterally
• Failed conservative treatment
• Patient willing to accept risks of intracranial surgery

Approaches

• Craniotomy above the ear; access the internal auditory canal (IAC) from above
• Divide the superior vestibular nerve (and inferior vestibular nerve if needed) within the IAC
• Preserves hearing (cochlear nerve spared)
• Requires temporal lobe retraction; risk of temporal lobe injury

• Posterior fossa craniotomy behind the sigmoid sinus
• Access the cerebellopontine angle (CPA)
• Section the vestibular nerve at its entry into the brainstem
• Good hearing preservation; surgeon must identify and spare the cochlear nerve
• More commonly used; familiar anatomy for neurotological surgeons

• Through mastoidectomy → labyrinthectomy → IAC access
• Sacrifices hearing completely — used only when hearing already lost
• Better exposure of CPA and cranial nerves

Results of Vestibular Neurectomy

• Vertigo control: 90% success (best of all procedures)
• Risk of SNHL: ~10%
• Risk of facial nerve injury: < 1% (experienced hands)
• Other risks: CSF leak, meningitis, headache

🔷 FLOWCHART 3: HEARING STATUS-BASED SURGICAL ALGORITHM

        MÉNIÈRE'S DISEASE
        Failed Medical Rx (≥3 months)
                 |
    _____________↓______________
   |                            |
UNILATERAL                  BILATERAL
   |                            |
   ↓                            ↓
Assess hearing              Avoid ablative Rx
in affected ear             IT steroids preferred
   |                        Meniett device
   ↓
___________
|         |
Serviceable  Non-serviceable
hearing      hearing
(PTA<50dB,   (PTA>50dB,
SDS>50%)     SDS<50%)
   |              |
   ↓              ↓
   Prefer:        Prefer:
   • ELS surgery  • Chemical labyrinthectomy
   • IT gentamicin  (IT Gentamicin, high dose)
     (low dose)   • Surgical labyrinthectomy
   • Vestibular     (transcanal/transmastoid)
     neurectomy
     (definitive)

5. COMPARISON TABLE OF SURGICAL PROCEDURES

AAO-HNS OUTCOME CLASSIFICATION (1996 Guidelines)

PART IV: RECENT ADVANCES (As Relevant to RGUHS)

1. Intratympanic Therapy Refinements

• Dexamethasone vs Methylprednisolone IT: methylprednisolone achieves higher perilymph/endolymph concentrations but not proven clinically superior; dexamethasone preferred for better middle ear tolerance
• Low-dose IT Gentamicin titration: single monthly injections to titrate vestibular ablation while monitoring hearing — reduces SNHL risk
• Sustained-release drug delivery systems (e.g., hydrogel-based IT devices) under investigation

2. Endolymphatic Hydrops Imaging

• MRI with gadolinium (IV or IT): can now directly visualize endolymphatic hydrops on 3T or 7T MRI — cochlear and vestibular hydrops quantified; being used as research and diagnostic tool
• Changing diagnostic paradigm toward objective confirmation

3. Meniett Device

• Low-pressure micropressure pulse generator via tympanostomy tube
• Used at home; improves vertigo control in some patients (particularly when ELS is not suitable)

4. Cochlear Implantation in Ménière's Disease

• Patients with bilateral MD and bilateral SNHL may benefit from CI
• Labyrinthectomy + simultaneous CI in selected patients

5. Vestibular Implant (Experimental)

• Prosthetic semicircular canal stimulation under development (analogous to cochlear implant)
• May provide tonic vestibular input after bilateral labyrinthectomy

6. Biomarkers & Genetics

• Autoimmune markers (anti-68 kDa heat shock protein), genetic susceptibility loci (chromosome 6p)
• Aquaporin-2 channels implicated in endolymph regulation — potential therapeutic target

SUMMARY FLOWCHART: COMPLETE MANAGEMENT OVERVIEW

SUSPECTED MÉNIÈRE'S DISEASE
          |
    CONFIRM DIAGNOSIS
    (AAO-HNS Criteria)
          |
    EXCLUDE DDx:
    BPPV, Vestibular Neuritis, Migraine,
    Acoustic Neuroma, AIED, Syphilis, PLF
    (MRI, Audiogram, ECoG, Caloric test, ABR, FTA-ABS)
          |
    MEDICAL MANAGEMENT (FIRST LINE)
    ─────────────────────────────
    • Low sodium diet < 2g/day
    • Diuretics (acetazolamide/hydrochlorothiazide)
    • Betahistine 16mg TID
    • Vestibular suppressants (acute attacks)
    • Vestibular rehabilitation
          |
    FAILED AFTER 3-6 MONTHS?
          |
         YES
          |
    ─────────────────────────────────
    MINIMALLY INVASIVE / OFFICE-BASED
    ─────────────────────────────────
    • IT Steroids (hearing-preserving)
    • IT Gentamicin (semi-ablative)
    • Meniett pressure therapy
          |
    STILL REFRACTORY?
          |
         YES
          |
    ─────────────────────────
    SURGICAL OPTIONS
    ─────────────────────────
         |
    ─────┬───────────────────────
    |    Serviceable Hearing?    |
    YES                         NO
    |                           |
    ELS Surgery             Labyrinthectomy
    Vestibular              (Chemical or Surgical)
    Neurectomy
    (MCF / Retrosigmoid)

CONCLUSION

• Cummings Otolaryngology Head and Neck Surgery (6th ed.) — Chapters 157, 158, 167
• K.J. Lee's Essential Otolaryngology (11th ed.) — Chapter on Surgery for Vertigo
• Graham MD, Kemink JL: Surgical management of Ménière's disease with endolymphatic sac decompression by wide bony decompression of the posterior fossa dura — Laryngoscope 94, 1984
• Furstenberg regimen (sodium restriction + diuretics) — classic medical management
• Itoh & Sakata (1987): First IT steroid protocol
• Garduño-Anaya et al.: Randomized controlled trial of IT dexamethasone
• AAO-HNS Committee on Hearing and Equilibrium, 1995 (revised 2015 Barany Society criteria)
• Bradley & Daroff's Neurology in Clinical Practice — Ménière Disease chapter