Intratympanic gentamicin injection for Meniere's disease primarily works by:

• A Reducing endolymph production by damaging the stria vascularis
• B Selective ototoxicity to type I vestibular hair cells of the cristae, reducing vertigo without destroying hearing ✓
• C Obliterating the endolymphatic duct surgically
• D Increasing endolymph resorption by the endolymphatic sac

Explanation

Intratympanic gentamicin performs a 'chemical labyrinthectomy' by selectively destroying type I vestibular hair cells (more sensitive to aminoglycosides than type II cells) in the semicircular canal cristae and macular neuroepithelium, abolishing the abnormal vestibular signals causing vertigo. The cochlea is relatively less affected at low doses, making this a vertigo-ablation procedure that attempts to spare residual hearing. Repeated injections increase cochleotoxicity risk. It is used for intractable Meniere's disease when medical management fails.

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.