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Posterior inferior cerebellar artery

The posterior inferior cerebellar artery (PICA), the largest branch of the vertebral artery, is one of the three main arterial blood supplies for the cerebellum, part of the brain. Occlusion of the posterior inferior cerebellar artery or one of its branches, or of the vertebral artery leads to lateral medullary syndrome also called Wallenberg syndrome.

Posterior inferior cerebellar artery
The three major arteries of the cerebellum: the SCA, AICA, and PICA (posterior inferior cerebellar artery)
Circle of Willis en.svg
Diagram of the arterial circulation at the base of the brain (PICA labeled at bottom right)
SourceVertebral artery
BranchesMedial branch
VeinInferior cerebellar veins
SuppliesCerebellum, choroid plexus of the fourth ventricle
LatinArteria cerebelli inferior posterior
Anatomical terminology



It winds backward around the upper part of the medulla oblongata, passing between the origins of the vagus nerve and the accessory nerve, over the inferior cerebellar peduncle to the undersurface of the cerebellum, where it divides into two branches.

The medial branch continues backward to the notch between the two hemispheres of the cerebellum; while the lateral supplies the under surface of the cerebellum, as far as its lateral border, where it anastomoses with the anterior inferior cerebellar and the superior cerebellar branches of the basilar artery.

Branches from this artery supply the choroid plexus of the fourth ventricle.

Clinical significanceEdit

A disrupted blood supply to this artery due to a blood clot or embolus will result in tissue damage and lead to lateral medullary syndrome, also known as posterior inferior cerebellar artery syndrome (PICA syndrome), or Wallenberg syndrome. Severe occlusion of this artery or to vertebral arteries could lead to Horner's Syndrome as well. Lateral medullary syndrome has many neurological symptoms.


This article incorporates text in the public domain from page 580 of the 20th edition of Gray's Anatomy (1918)

External linksEdit

  • Anatomy photo:28:09-0225 at the SUNY Downstate Medical Center
  • "Anatomy diagram: 13048.000-1". Roche Lexicon - illustrated navigator. Elsevier. Archived from the original on 2014-01-01.
The arteries of the base of the brain. Posterior inferior cerebellar artery labeled at bottom. The temporal pole of the cerebrum and a portion of the cerebellar hemisphere have been removed on the right side. Inferior aspect (viewed from below).