Prevalence, clinical features, and radiological pattern of artery of Percheron infarction. a challenging diagnosis

Purpose Occlusion of artery of Percheron (AOP), a rare variant of paramedian branches of posterior cerebral artery, results in a characteristic pattern of ischemic lesions in bilateral paramedian thalami with or without midbrain and anterior thalami involvement. Aim To evaluate the prevalence, the clinical, and the imaging features of AOP infarction in a single comprehensive stroke center experience. Methods We retrospectively search in our stroke center database, patients with ischemic lesions in the AOP distribution. We collected clinical features and time between hospital admission and diagnosis. Imaging findings were categorized fol- lowing a pre-selected classification. Results Of 2830 ischemic stroke admitted in our center, we identified 15 patients with AOP infarction (0.53%). Clinical manifestations were variable, but oculomotor disturbances, particularly vertical gaze palsy, were the most observed, followed by consciousness impairment, varying from drowsiness to coma. The most frequent imaging pattern was bilateral paramedian thalamic infarction with midbrain infarction, and the V-sign was recognized in 6 cases from this group. In 8 patients a fetal origin of the PCA was observed. The average time from first hospital admission to diagnosis was 28.09 h. Conclusions The prevalence of AOP infarction in our center was 0.53%. Diagnosis of AOP infarction can be challenging and should be suspected in case of sudden altered consciousness.