What are the clinical features of Wallenberg syndrome associated with a PICA infarction involving the medulla?

Wallenberg syndrome, or lateral medullary syndrome, presents with ataxia, ipsilateral facial numbness, Horner syndrome, dysphagia, and dysarthria. Key diagnostic features include vertigo, nystagmus, and contralateral loss of pain and temperature sensation. A clinical pearl is that hoarseness and hiccups can also occur due to involvement of the nucleus ambiguus. Common pitfalls include confusing it with cerebellar infarction, which lacks the sensory deficits seen in Wallenberg syndrome.