What is Meniere’s disease?

What is Meniere's Disease?

Meniere's disease is a chronic inner ear disorder characterized by recurrent episodes of spontaneous rotational vertigo lasting 20 minutes to 12 hours, fluctuating low-to-mid-frequency sensorineural hearing loss, tinnitus, and aural fullness, with endolymphatic hydrops (excessive endolymph fluid accumulation in the membranous labyrinth) as its key pathological hallmark. 1, 2

Core Clinical Features

The disease presents with a specific symptom complex that must meet strict diagnostic criteria:

• Vertigo attacks: Two or more spontaneous episodes of true rotational vertigo, each lasting 20 minutes to 12 hours (not seconds or days, which suggest other diagnoses) 2, 3
• Hearing loss: Audiometrically documented fluctuating sensorineural hearing loss affecting low-to-mid frequencies in the affected ear, documented before, during, or after at least one vertigo episode 2, 3
• Fluctuating aural symptoms: Tinnitus and aural fullness (pressure sensation) in the affected ear that vary in intensity with disease activity, often worsening before or during attacks 2, 3

Underlying Pathophysiology

• Endolymphatic hydrops is the histopathological hallmark, representing excessive buildup of endolymph fluid in the membranous labyrinth that causes distortion and damage to ganglion cells 1, 4
• The exact cause remains unknown but involves multifactorial contributors including genetic predisposition, autoimmune processes, infection, trauma, and vascular insufficiency 1, 5
• The disease likely results from deficiency in endolymph absorption, though the precise mechanism linking hydrops to clinical symptoms requires further study 4, 6

Disease Progression and Additional Features

• Hearing loss pattern: Initially fluctuates but may eventually involve all frequencies as the disease progresses, with complete restoration not currently possible 2
• Drop attacks (Tumarkin's otolithic crisis): Sudden falls without loss of consciousness or warning may occur in later stages 2, 3
• Bilateral involvement: Affects both ears in 10-25% of cases over time, which is critical for surgical decision-making 2, 5
• Chronic imbalance: Persistent unsteadiness between acute attacks may develop, representing ongoing vestibular dysfunction 3

Key Differential Diagnoses to Exclude

• Vestibular migraine: Vertigo episodes lasting minutes to days, often with headache history 2
• BPPV: Brief vertigo episodes (seconds) provoked by head position changes 2, 3
• Vestibular neuritis: Acute prolonged vertigo without hearing loss 2, 3
• Labyrinthitis: Sudden severe vertigo with prolonged symptoms (>24 hours) and hearing loss 2, 3
• Cerebellopontine angle tumors: Progressive unilateral hearing loss with imbalance 2

Epidemiology and Demographics

• Most common in adults with average onset in the fourth decade, typically between ages 20-60 years 6
• Affects both sexes and both ears with fairly equal frequency 6
• Racial (genetic) and environmental factors influence incidence variations across populations 6

Important Clinical Pitfalls

• Diagnosis is by exclusion requiring careful history and appropriate testing to rule out mimics 2, 6
• Placebo response is high: 60% of patients show improvement with placebo in clinical trials, making treatment efficacy difficult to assess 2
• Symptom timing is critical: Episodes lasting seconds suggest BPPV, while episodes lasting days suggest labyrinthitis or vestibular neuritis 3