Ménière's disease

Recurrent attacks of spinning vertigo with fluctuating low-frequency hearing loss and aural fullness. SHA is often surprisingly bland between attacks — the chair earns its keep by quantifying cumulative damage over years.

Clinical picture

The Bárány-Society criteria require two or more spontaneous episodes of vertigo each lasting 20 minutes to 12 hours, audiometrically documented low-to-mid-frequency hearing loss on the affected side, fluctuating aural symptoms, and exclusion of alternative diagnoses Lopez-Escamez JA 2015.

Pathophysiology

Endolymphatic hydrops — pathological distension of the endolymphatic compartment — is the consistent histopathological finding, although the causal mechanism is debated. Repeated episodes lead to gradual hair-cell loss; by the “burnt-out” stage unilateral vestibular function is severely reduced.

RCT pattern

Between attacks SHA is often normal or only mildly asymmetric; the caloric weakness usually appears first because the caloric stimulus probes the most vulnerable, lowest-frequency range. Late in the disease the RCT shows a fixed unilateral pattern — reduced gain, elevated phase lead, persistent directional preponderance — that is hard to tell apart from a slowly compensating neuritis.

Diagnosis & differential

• Audiogram showing the characteristic fluctuating low-frequency loss.
• Bilateral hydrops on delayed-gadolinium MRI when available.
• VEMP changes (reduced cVEMP amplitude, raised oVEMP threshold) support but do not confirm the diagnosis.
• RCT mostly excludes a bilateral process and tracks cumulative damage.