Posterior inferior cerebellar artery

The posterior inferior cerebellar artery (PICA) is one of the three main arteries that supply blood to the cerebellum, the other two being the anterior inferior cerebellar artery (AICA) and the superior cerebellar artery (SCA). The PICA is the largest branch of the vertebral artery and is crucial for providing oxygenated blood to the cerebellum and parts of the medulla oblongata.

Anatomy

The PICA typically arises from the vertebral artery just before it merges with the opposite vertebral artery to form the basilar artery. It courses around the medulla oblongata and then ascends to supply the inferior part of the cerebellum. The artery is divided into several segments, including the anterior medullary, lateral medullary, and tonsillomedullary segments, each named for the regions they supply.

Function

The primary function of the PICA is to supply blood to the posterior and inferior regions of the cerebellum, which are involved in coordinating voluntary movements, balance, and posture. Additionally, it supplies parts of the medulla oblongata, which is responsible for autonomic functions such as breathing, heart rate, and blood pressure regulation.

Clinical Significance

Occlusion or blockage of the PICA can lead to a type of stroke known as a lateral medullary syndrome (also known as Wallenberg syndrome). This condition is characterized by a range of symptoms including difficulty swallowing, hoarseness, dizziness, nausea, and loss of pain and temperature sensation on one side of the body. Prompt medical attention is required to manage and treat this condition.

See Also

• Cerebellum
• Vertebral artery
• Basilar artery
• Lateral medullary syndrome
• Anterior inferior cerebellar artery
• Superior cerebellar artery