Paradoxical brain embolism in a young man: is it only a patent foramen ovale?

Paradoxical embolism is considered the major cause of cerebral ischemic events in young patients. The most common cause of paradoxical embolism, which has been widely described, is right-to-left shunting (RLS) at cardiac level through a patent foramen ovale (PFO). Rarely paradoxical embolism can also be caused by RLS at pulmonary level due to pulmonary arteriovenous fistula (PAVF). Herein, we present a case of a young man, who experienced transient ischemic attack (TIA) due to paradoxical embolism, in whom both abovementioned abnormalities coexisted. This coincidence is very rare (noted in only 1% of patients with cryptogenic stroke or TIA), but it highlights the importance of searching for extracardiac RLS in patients with cryptogenic stroke, even if a PFO has been detected.