A clinical study of artery of Percheron infarction.

Artery of Percheron (AOP) infarction, a rare cause of acute altered mental status (AMS), is characterized by bilateral paramedian thalamic infarction. The aim of this study was to review the clinical manifestation, radiological patterns, treatment, and prognosis of patients with AOP infarction. This retrospective case series included patients with AOP infarction from 2009 to 2020 from a medical center in Taiwan. We defined AOP infarction as acute bilateral paramedian thalamic infarction from magnetic resonance imaging, and patients were further categorized by their additional AOP territorial involvements. We determined outcomes with the modified Rankin Scale at discharge. Among the 10 included patients, AMS was the most common presentation (90%). We identified two patients with bilateral vertebral artery (VA), five with unilateral posterior cerebral artery (PCA), and one with bilateral PCA occlusion. Atherosclerosis was the most common presumed etiology (60%). Two and eight patients had favorable and unfavorable prognoses, respectively. PCA occlusion, rather than VA and BA occlusion, was common in angiography. Residual symptoms often resulted in significant disability at discharge. Basilar tip syndrome may share indistinguishable thalamic infarct patterns with AOP infarction but could be differentiated by angiography and other infarcted territories.