Managing anticoagulation and thromboembolic risk in cryptogenic stroke associated with patent foramen ovale.

Cryptogenic stroke (CS) in young adults may be associated with the presence of a patent foramen ovale (PFO). This case report presents a woman in her 40s admitted with sudden left hemiplegia. Imaging confirmed an ischaemic stroke in the right middle cerebral artery territory and occlusion of the right internal carotid artery. Further investigations identified a large PFO associated with an atrial septal aneurysm. An in-depth assessment revealed a distal deep vein thrombosis (DVT). Initial anticoagulation therapy was interrupted due to severe metrorrhagia, necessitating the placement of an inferior vena cava (IVC) filter. Subsequent extensive thrombosis of the IVC led to initiation of low molecular weight heparin followed by long-term direct oral anticoagulants. This case highlights the complexity of managing CS with PFO, emphasising the importance of thorough aetiological evaluation to distinguish pathogenic from incidental PFO, and the need for a personalised and multidisciplinary therapeutic strategy to balance thromboembolic and haemorrhagic risks effectively.