A 55-year-old man with no significant past medical history presented with acute dysphasia, confusion, and dysarthria. Brain MRI revealed a small left insular cortical infarct. Extensive evaluation, including thrombophilia screening, carotid duplex, and CT angiography, was unrevealing. Agitated-saline transthoracic echocardiogram (TTE) demonstrated a large right-to-left shunt, and transesophageal echocardiographic (TEE) confirmed an aneurysmal interatrial septum with a paten foramen ovale (PFO, tunnel height 0.6 cm, length 0.8 cm) and immediate bubble crossover within three cardiac cycles, consistent with a high-grade shunt. The PFO multidisciplinary team considered the event likely PFO-related (ROPE score 7), and percutaneous closure was recommended.