Acute bilateral cerebellar infarction due to occlussion of a single posterior inferior cerebellar artery

A 54-year-old hypertensive man developed a Wallenberg's syndrome. Gadolinium-enhanced magnetic resonance imaging showed an acute infarction involving the dorsal and lateral aspect of the left medulla as well as the entire territory of the left posterior inferior cerebellar artery and that of the medial branch of the right posterior inferior cerebellar artery. Cerebral angiography revealed occlusion of the left posterior inferior cerebellar artery and absence of the right vertebral artery. The infarction followed a benign course and the patient was discharged almost asymptomatic. This is the second clinicoradiological report of acute bilateral cerebellar infarction related to the occlusion of a single posterior inferior cerebellar artery. Both reports suggest that when there is agenesis or hypoplasia of one posterior inferior cerebellar artery, the medial branch of the contralateral posterior inferior cerebellar artery provides vascular supply to both sides of the caudal vermis.