A patient with Meniere's disease refractory to conservative treatment (low-sodium diet, diuretics, betahistine) is being considered for intratympanic gentamicin therapy. The primary mechanism of action of this treatment is:

• A Anti-inflammatory reduction of endolymphatic hydrops via glucocorticoid receptors in the dark cells
• B Reduction of endolymph secretion by the dark cells of the vestibular labyrinth via aminoglycoside toxicity
• C Chemical ablation of the type I hair cells of the saccule and utricle, reducing vestibular function and episodic vertigo ✓
• D Constriction of the endolymphatic sac vasculature, reducing endolymph production

Explanation

Intratympanic gentamicin (ITG) is a vestibulotoxic aminoglycoside used to chemically ablate the vestibular end organs (particularly type I hair cells of the saccule and utricle) in Meniere's disease. This reduces the abnormal vestibular signals that trigger episodic vertigo. Hearing loss is a dose-dependent risk. Intratympanic corticosteroids (dexamethasone) are used for hearing preservation and do not ablate the labyrinth.

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.