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.

Course

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.

Diseases

Infarction of this artery due to thrombosis or a stroke leads to posterior inferior cerebellar artery syndrome (PICA syndrome), also known as lateral medullary syndrome, or Wallenberg syndrome. Severe occlusion of this or vertebral arteries could lead to Horner's Syndrome as well.

References

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

External links

• DDB 10449
• Anatomy photo:28:09-0225 at the SUNY Downstate Medical Center
• Anatomy diagram: 13048.000-1 at Roche Lexicon - illustrated navigator, Elsevier

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).