The blood supply to the lateral wall of the scala vestibuli and the stria vascularis is primarily derived from which vessel, and why is this clinically relevant in aminoglycoside ototoxicity?

• A Posterior inferior cerebellar artery (PICA) — its occlusion causes lateral medullary syndrome with hearing loss
• B Anterior inferior cerebellar artery (AICA) directly — branching to the stria vascularis
• C Superficial temporal artery via stylomastoid foramen collaterals
• D Labyrinthine artery (internal auditory artery, branch of AICA) — the end-arterial nature means any ischaemia or drug accumulation causes irreversible cochlear damage ✓

Explanation

The stria vascularis of the cochlea is supplied by the labyrinthine artery (cochlear branch of the internal auditory artery, itself a branch of the AICA). Critically, this is an end-artery with no collateral blood supply. Aminoglycosides preferentially accumulate in the stria vascularis and outer hair cells of the basal cochlea (high-frequency region) and are not cleared efficiently due to the end-arterial supply. This end-organ accumulation leads to irreversible oxidative damage to outer hair cells, causing high-frequency SNHL that may progress even after drug cessation.

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.