From which artery do the Posterior Inferior Cerebellar Arteries (PICA) typically originate, and what is their clinical significance?

The Posterior Inferior Cerebellar Arteries (PICA) typically arise from the distal vertebral artery, approximately 1 to 2 cm below the origin of the basilar artery. Key diagnostic features include their role in supplying the cerebellum and medulla, making them crucial in conditions like lateral medullary syndrome (Wallenberg syndrome). Clinically, PICA infarcts can result in vertigo, ataxia, and sensory deficits. A common pitfall is mistaking PICA infarcts for other posterior circulation strokes, emphasizing the need for careful imaging interpretation.