A 42-year-old woman presents to the ENT clinic with a 6-month history of episodic vertigo lasting 2–4 hours, accompanied by fluctuating low-frequency sensorineural hearing loss, tinnitus, and a sensation of fullness in the left ear. Between episodes, she is asymptomatic. Audiometry shows a characteristic U-shaped or rising audiogram with low-frequency hearing loss (250–1000 Hz). Caloric testing reveals reduced response on the left. MRI of the internal auditory canal is normal. What is the most likely diagnosis?

Explanation

## Diagnosis: Meniere Disease ### Classic Presentation **Key Point:** Meniere disease is characterized by the tetrad of episodic vertigo, fluctuating sensorineural hearing loss, tinnitus, and aural fullness—all unilateral and recurring. ### Diagnostic Criteria (Modified American Academy of Otolaryngology–Head and Neck Surgery) | Criterion | Finding in This Case | |-----------|----------------------| | **Episodic vertigo** | 2–4 hours duration, recurrent ✓ | | **Hearing loss** | Fluctuating, low-frequency SNHL ✓ | | **Tinnitus** | Present ✓ | | **Aural fullness** | Present ✓ | | **Unilateral symptoms** | Left ear only ✓ | | **Audiometry pattern** | U-shaped/rising (low-freq loss) ✓ | | **Caloric abnormality** | Reduced left response ✓ | | **MRI normal** | Rules out retrocochlear pathology ✓ | **High-Yield:** The **U-shaped or rising audiogram** (low-frequency SNHL) is pathognomonic for early Meniere disease and distinguishes it from noise-induced or age-related hearing loss (which show high-frequency loss). ### Pathophysiology **Clinical Pearl:** Meniere disease results from **endolymphatic hydrops**—abnormal accumulation of endolymph in the cochlea and vestibule. This causes: 1. Cochlear dysfunction → fluctuating low-frequency hearing loss 2. Vestibular dysfunction → episodic vertigo 3. Increased pressure in the membranous labyrinth → aural fullness and tinnitus ### Why MRI is Normal **Key Point:** MRI rules out retrocochlear causes (vestibular schwannoma, demyelination). Meniere disease is a **functional disorder of endolymphatic regulation**, not a structural lesion—hence normal imaging. ### Differential Features | Feature | Meniere | BPPV | Vestibular Schwannoma | Sudden SNHL | |---------|---------|------|----------------------|-------------| | **Vertigo duration** | Hours | Seconds–minutes | Chronic progressive | Single episode | | **Hearing loss** | Fluctuating, low-freq | None | Progressive, high-freq | Sudden onset | | **Tinnitus** | Yes | No | Often | Sometimes | | **Aural fullness** | Yes | No | No | No | | **Caloric test** | Reduced (affected side) | Normal | Reduced (affected side) | Normal | | **MRI** | Normal | Normal | Tumor visible | Normal | | **Audiogram pattern** | U-shaped | — | High-freq loss | Variable | **Mnemonic:** **FVTA** = Fluctuating hearing loss, Vertigo (episodic), Tinnitus, Aural fullness (Meniere tetrad). ### Management Overview 1. **Acute vertigo:** Vestibular suppressants (cinnarizine, betahistine), antiemetics 2. **Long-term:** Salt restriction, diuretics (hydrochlorothiazide), betahistine 3. **Refractory:** Intratympanic corticosteroids, gentamicin, or endolymphatic sac surgery [cite:Dhingra 8e Ch 5]