Basilar Artery

Contents

Basilar Artery
CATEGORY 1PENDING

A single artery supplying part of the posterior circulation of the brain.

The confluence of the left and right vertebral arteries at the pontomedullary junction.

Ascends superiorly in a ventral midline groove of pons termed the basilar sulcus.
Divides at the junction of the midbrain and pons into the posterior cerebral arteries

Anterior Inferior Cerebellar Artery (AICA)
- branch of the proximal basilar artery, courses posteriorly lateral to pons, near pontomedullary junction
- Supplies anterolateral surface of inferior cerebellum
Labyrinthine artery (variant)
- accompanies facial and vestibulocochlear nerve into internal acoustic meatus, may arise from AICA
Pontine perforators
- 3 – 5 small branches located in the mid-basilar region
- Supplies the pons and adjacent structures
Superior Cerebellar Artery (SCA)
- Branch of the distal basilar near the junction of pons and midbrain, just before its terminal bifurcation, arises just inferior to oculomotor nerve
- Supplies from the superior surface of the cerebellum to the great horizontal fissure, superior vermis, dentate nucleus and most of the cerebellar white matter and parts of midbrain
Posterior Cerebral Artery (PCA)
- Terminal branch of the basilar artery
- See Posterior Cerebral Artery

Abducens nerve exits brainstem lateral to basilar origin
Oculomotor nerve exits the interpeduncular fossa of midbrain between the superior cerebellar artery and posterior cerebral artery
Trochlear nerve arises from the posterior midbrain, inferior to inferior colliculus, and passes anteriorly between SCA and PCA

Variable AICA origin: arising from the middle third of basilar artery or vertebrobasilar junction
Fenestration
Persistent carotid-vertebrobasilar anastomoses
- Persistent trigeminal artery
- Persistent otic artery
Unfused upper basilar
Common posterior cerebral and superior cerebellar artery trunk
Anterior spinal artery from basilar origin
Formed by unilateral vertebral artery

Updated on 13 August 2021