Wallenberg's syndrome with extradural-extracranial origin of the posterior inferior cerebellar artery.

We report a case of lateral medullary syndrome (LMS) with extradural origin of the posterior inferior cerebellar artery (PICA). A 45-year-old construction worker presented with acute signs and symptoms of typical LMS. Prolonged work-related neck extension was reported just prior to the onset of symptoms. Cerebral angiography revealed a patent vertebrobasilar tree with an extradural origin of an otherwise normal appearing PICA ipsilaterally. Workup did not show evidence for cardioembolic or atheroembolic source. The presence of an extradural origin of PICA may be considered a predisposing factor for non-traumatic LMS associated with head and neck movement.