Lateral Medullary Syndrome Due to a Hypoplastic Vertebral Artery

Vertebral artery hypoplasia is an uncommon congenital anatomical variation. Currently, no standard criteria exist for evaluating vertebral arteries as being hypoplastic based on vessel luminal diameter or volume flow. There is debate on the clinical significance of these variants and their relevance as an independent risk factor for posterior circulation strokes. We report a case of a 59-year-old male presenting with lateral medullary syndrome in the setting of a left hypoplastic vertebral artery with absence of atherosclerotic or thrombotic involvement.