Artery of Percheron Strokes: Three Cases in Three Months.

The artery of Percheron (AOP) is a rare variant of thalamic vasculature and is a single dominant thalamoperforating artery supplying bilateral paramedian thalamic territories. Occlusion of the AOP results in a characteristic pattern of bilateral paramedian thalamic infarcts and is estimated to represent between 0.1%-0.3% of all ischemic strokes and 4% to 35% of all thalamic strokes. Four distinct ischemic patterns of AOP infarcts have been identified: bilateral paramedian thalamic region with midbrain (43%), bilateral paramedian thalamic without midbrain (38%), bilateral paramedian thalamic with anterior thalamus and midbrain involvement (14%), and bilateral paramedian thalamic with anterior thalamus without midbrain involvement (5%). Despite our knowledge of the characteristic radiologic features of an AOP stroke, the true incidence of AOP strokes is challenging to estimate due to non-specific clinical symptoms and subtle findings on computed tomography (CT) and/or magnetic resonance imaging (MRI). Here, we present a case series of three patients seen within a 3-month span at one community hospital seen by one single neurologist with confirmed AOP stroke by radiologic imaging. The frequency of these cases suggests that the incidence of AOP infarctions may be higher than previously estimated and instead are underreported due to broad differential on clinical and imaging presentation.