Which artery is infarcted in Wallenberg syndrome?

Wallenberg syndrome, also known as lateral medullary syndrome, is caused by an infarction in the territory supplied by the posterior inferior cerebellar artery (PICA). This artery supplies blood to the inferior part of the cerebellum and the lateral medulla oblongata.

The clinical manifestations of Wallenberg syndrome include ataxia, dysphagia, dysarthria, and sensory deficits, among others, which correspond to the areas affected by the loss of blood supply due to the occlusion of PICA. Being the primary artery involved, it is crucial to recognize its role in this neurological condition, as understanding the vascular supply helps in diagnosing the syndrome effectively and guiding treatment.

The involvement of other arteries mentioned in the options does not directly lead to Wallenberg syndrome. The anterior cerebral artery primarily supplies the medial portions of the frontal lobes and the superior medial parietal lobes, while the vertebral artery supplies parts of the brainstem and cerebellum but not specifically the areas affected in Wallenberg syndrome. The pulmonary artery is unrelated, as it supplies the lungs and has no role in cerebral infarction.