Unmasking Paradoxical Embolism: Cerebellar Stroke Linked to Coexisting Arteria Lusoria and Patent Foramen Ovale

Abstract

Background: The aberrant right subclavian artery (ARSA), or Arteria Lusoria, is a rare congenital anomaly of the aortic arch, often asymptomatic but capable of diverse presentations. Similarly, a patent foramen ovale (PFO) is a common cardiac anomaly, but its association with atrial septal aneurysm (ASA) significantly increases the risk of paradoxical embolism and stroke. The co-occurrence of ARSA with PFO and ASA, particularly with ARSA plaque formation, represents a uniquely complex and under-recognized risk profile for cerebrovascular events. Case Presentation: We present a 64-year-old male with a history of hypertension, hyperlipidemia, and cholelithiasis who presented with acute cerebellar stroke. Investigations revealed ARSA and a patent foramen oval (PFO) with atrial septal aneurysm (ASA). Discussion: This case strikingly illustrates a rare triad of anatomical variants (ARSA with plaque, PFO, and ASA) that together likely contributed to a paradoxical embolism leading to cerebellar stroke. It highlights the critical interplay between congenital anomalies and acquired risk factors, emphasizing how such a combination can create a prothrombotic environment and facilitate embolic transit. The diagnostic utility of multimodal imaging was paramount in uncovering these concurrent findings, guiding subsequent management. Conclusions: This case underscores the importance of considering uncommon anatomical variations during stroke workup, especially when dealing with atypical presentations or increased risk factors. This approach can improve diagnostic accuracy and contribute to optimal patient care.