Vessel
Basilar artery
The central trunk of vertebrobasilar circulation
High-yield
Recognize the route vertebral arteries → basilar trunk → PCAs. AICA generally branches more caudally and SCA near the basilar termination, while pontine branches arise along the trunk.
Overview
The vertebral arteries usually unite near the pontomedullary junction to form the basilar artery. It ascends in the cistern in front of the pons and divides rostrally into the posterior cerebral arteries. Along the way, numerous pontine and cerebellar branches distribute flow; their origins do not form one invariant sequence.
Reference facts
- Origin
- Normally the union of the two vertebral arteries near the junction of medulla and pons.
- Course
- Runs upward in the prepontine cistern, usually along the ventral pontine groove, toward the interpeduncular region.
- Branches
- Pontine perforating/circumferential branches, AICAs and SCAs, ending in PCAs. The labyrinthine artery usually arises through AICA but can branch directly.
- Supplies
- Through its branches, much of the pons and portions of cerebellum and inner ear. Terminal PCA pathways reach midbrain, thalamus and posterior cerebral territories.
Clinical correlation
Basilar occlusion can produce a wide range of brainstem and posterior-circulation deficits. Extensive ventral pontine injury may cause locked-in syndrome, with severe limb and speech-motor paralysis despite retained awareness. Residual blinking or vertical eye movements vary with lesion extent.
Frequently asked questions
Where does the basilar artery originate?
The basilar artery arises from the normally the union of the two vertebral arteries near the junction of medulla and pons.
What does the basilar artery supply?
Through its branches, much of the pons and portions of cerebellum and inner ear. Terminal PCA pathways reach midbrain, thalamus and posterior cerebral territories.
What are the branches of the basilar artery?
Pontine perforating/circumferential branches, AICAs and SCAs, ending in PCAs. The labyrinthine artery usually arises through AICA but can branch directly.
What is the course of the basilar artery?
Runs upward in the prepontine cistern, usually along the ventral pontine groove, toward the interpeduncular region.