ABSTRACT NUMBER: ESOC2026A2180 ATYPICAL STROKE: ATHEROEMBOLISM FROM THE COMMON CAROTID ARTERY TO BRANCHES OF THE POSTERIOR CEREBRAL ARTERY

Abstract Background and aims The presence of an organized thrombus in the common carotid artery can generate microemboli to uncommon cerebral territories, especially in the presence of anatomical variants, causing atypical ischemic strokes. In this case, we present this rare clinical scenario. Methods Descriptive presentation of a clinical case. Results A 49-year-old man with multiple cardiovascular risk factors and significant atherosclerotic burden presented to the emergency department with confusion and visual disturbances, evolving over six hours. On examination, he showed: Rightward oculocephalic deviation Left inferior quadrantanopia Left-sided hemihypesthesia NIHSS score: 2 He also had markedly elevated blood pressure, raising initial suspicion of hypertensive encephalopathy or posterior fossa stroke. Cranial CT showed no acute lesions, and the patient was admitted to the Stroke Unit. Etiological studies with carotid neurosonology revealed an organized thrombus along the right common carotid artery, confirmed by CT angiography, which also showed a fetal origin of the right posterior cerebral artery (PCA). Brain MRI demonstrated ischemic lesions in the posterior thalamic and hippocampal regions, consistent with involvement of the posterior choroidal artery, suggesting thrombotic migration via the anatomical variant (fetal origin of the right PCA). Conclusions In patients with ischemic stroke in unusual territories, proximal carotid thrombus and vascular anatomical variants should be considered as potential embolic sources. Early recognition and targeted imaging are essential to guide treatment and prevent recurrence. Conflict of interest Daniel Antonio Ginarte Milanés: Nothing to disclose Figure 1 - belongs to Results