Labyrinthine artery

The labyrinthine artery (a.k.a. the internal auditory artery), is a small end-artery that most commonly arises from the anterior inferior cerebellar artery (AICA). Less commonly, it originates directly from the basilar artery.

Course of the labyrinthine artery

After its origin, the labyrinthine artery courses through the cerebellopontine angle toward the internal auditory meatus and accompanies the facial (CN VII) and vestibulocochlear (CN VIII) nerves through the internal acoustic canal.

Intrameatal branching and vascular territory

Upon entering the internal acoustic canal, the labyrinthine artery divides into terminal branches; the anterior vestibular and the common cochlear arteries.

• Anterior Vestibular Artery: Perfuses the utricle, superior and lateral semicircular canals, and the superior vestibular nerve.

• Common Cochlear Artery: Further bifurcates into the:

  • Proper Cochlear Artery: Supplies the spiral modiolar vascular network and the cochlea responsible for auditory transduction.

  • Vestibulocochlear Artery: Perfuses the saccule, posterior semicircular canal, and the basal turn of the cochlea.

Clinical correlate

• The labyrinthine artery functions as a terminal end-artery with essentially absent collateral circulation, rendering the cochleovestibular apparatus exceptionally vulnerable to ischemia or vasospasm.

• Because the labyrinthine artery arises from the AICA in roughly three-quarters of individuals, AICA occlusion (in lateral pontine syndrome) classically compromises the labyrinthine artery, contributing to sudden-onset ipsilateral sensorineural hearing loss, tinnitus, and acute peripheral vertigo alongside brainstem signs.