Vessel
Posterior cerebral artery
Visual, medial temporal and deep posterior brain supply
High-yield
Occipital PCA infarction can cause an opposite homonymous field defect. Central vision may be spared when occipital-pole tissue remains perfused, but macular sparing is not guaranteed.
Overview
Each PCA usually arises at the basilar termination and turns around the midbrain toward the posterior hemisphere. In a fetal configuration, the ICA provides dominant flow through a large PCom. Perforating and choroidal branches supply deep structures; cortical branches reach occipital and inferomedial temporal regions. CN III usually emerges between PCA and SCA.
Reference facts
- Origin
- Usually the basilar bifurcation. Fetal-type configurations have dominant internal-carotid input through PCom, with a small or absent P1 connection.
- Course
- P1 reaches PCom; P2 curves around the midbrain; P3 occupies the quadrigeminal region; distal cortical branches include calcarine and parieto-occipital vessels. Segment terminology varies.
- Branches
- Thalamic and midbrain perforators, posterior choroidal arteries, and temporal, parieto-occipital and calcarine cortical branches.
- Supplies
- Occipital/visual cortex, inferomedial temporal regions, splenial callosal territory and parts of thalamus and midbrain, with individual overlap and variation.
Clinical correlation
Dominant posterior injury involving visual and connecting pathways can impair reading while leaving writing relatively preserved. A Percheron variant can connect one arterial origin to both paramedian thalami, so a single occlusion may cause bilateral injury with variable alertness, memory and gaze deficits.
Frequently asked questions
Where does the posterior cerebral artery originate?
Usually the basilar bifurcation. Fetal-type configurations have dominant internal-carotid input through PCom, with a small or absent P1 connection.
What does the posterior cerebral artery supply?
Occipital/visual cortex, inferomedial temporal regions, splenial callosal territory and parts of thalamus and midbrain, with individual overlap and variation.
What are the branches of the posterior cerebral artery?
Thalamic and midbrain perforators, posterior choroidal arteries, and temporal, parieto-occipital and calcarine cortical branches.
What is the course of the posterior cerebral artery?
P1 reaches PCom; P2 curves around the midbrain; P3 occupies the quadrigeminal region; distal cortical branches include calcarine and parieto-occipital vessels. Segment terminology varies.