Abstract 180: Acute Encephalopathy : A Presentation To Be Aware of During Stroke Alerts

Acute encephalopathy has been described as a poor predictor of ischemic stroke with a final diagnosis of stroke in 8 ‐9 % of stroke alerts. The Artery of Percheron (AOP) is an anatomic variant of the paramedian arteries that arises from the P1 segment of the posterior cerebral artery (PCA) and supplies bilateral medial thalami and part of the rostral midbrain. Its occlusion causes ischemia in the bilateral paramedian thalami with variable midbrain involvement. The frequency of strokes due to AOP occlusion ranges from 0.1‐2% of all ischemic strokes. While stroke is classically characterized by a focal and unilateral deficit, posterior circulation strokes (basilar, or thalamic) can present with encephalopathy or even bilateral deficits representing a challenge when patients are in a window for thrombolytic therapy.