Artery of Percheron Stroke

Occlusion of the Artery of Percheron (AOP) is present in ~ 8% of the population and can cause bilateral paramedian thalami and midbrain stroke. The thalami have four main vascular territories: anterior, paramedian, posterior, and inferolateral.

• The paramedian territories are supplied by paramedian arteries from the posterior circulation.

There are four variants of paramedian thalamic blood supply:

• Variant I: Normal (Most Common). Perforating branches arise separately from the right and left posterior cerebral arteries (PCAs).
• Variant IIa: Both paramedian arteries originate from the left P1 segment.
• Variant IIb: The P1 segment of the PCA feeds the AOP, which then supplies the bilateral paramedian thalami and rostral midbrain.
• Variant III: The bilateral PCAs form an arcade variant, which bridges together to supply the bilateral paramedian thalami.

For further review, see: Artery of Percheron Infarction: A Short Review