Lateral Medullary Ischemic Infarct Caused by Posterior Inferior Cerebellar Artery Aneurysm.

Posterior inferior cerebellar artery (PICA) aneurysms are rare. The most common complication of intracranial aneurysms is rupture causing subarachnoid hemorrhage. Ischemic infarct, although more common in giant thrombosed aneurysms, is a very rare manifestation of small intracranial aneurysms. Here we describe a patient who presented with lateral medullary acute infarction associated with an ipsilateral, small (4 × 3.5 mm), unruptured and non-thrombosed PICA aneurysm.