A 45-year-old woman presents with episodic vertigo lasting 20–30 minutes, unilateral tinnitus, aural fullness, and fluctuating low-frequency sensorineural hearing loss. Glycerol dehydration test shows >15 dB improvement in thresholds. The pathophysiology involves:

• A Calcium carbonate debris accumulation in the posterior semicircular canal
• B Demyelination of the eighth nerve axons at the internal auditory meatus
• C Fibrosis of the endolymphatic sac secondary to chronic otitis media
• D Endolymphatic hydrops with raised endolymphatic pressure ✓

Explanation

The described clinical picture is Meniere's disease (endolymphatic hydrops). The glycerol test exploits osmotic reduction of endolymphatic pressure — improvement of ≥10 dB in PTA or ≥12% in word discrimination score is a positive result confirming hydrops. The accumulation of calcium debris describes BPPV; demyelination describes vestibular neuritis/acoustic neuritis; and endolymphatic sac fibrosis is a secondary cause of secondary endolymphatic hydrops.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.