[A case of spectacular shrinking deficit caused by paradoxical cerebral embolism secondary to pulmonary arteriovenous fistula].

We report a case of spectacular shrinking deficit caused by paradoxical cerebral embolism through pulmonary arteriovenous fistula (AVF). A 79-year-old female suddenly developed right hemiplegia, paresthesia, and speech disturbance symptoms that were improved within 20 min, indicating a diagnosis of spectacular shrinking deficit. Brain magnetic resonance imaging revealed acute cerebral infarcts in the left parietal cortex of the left middle cerebral arterial territory. A contrast-enhanced chest computed tomography scan revealed a pulmonary AVF in the middle lobe of the right lung. The patient had deep venous thrombosis in her left lower leg. She had no clinical signs of telangiectasia, did not exhibit recurrent epistaxis, and had no family history of hereditary hemorrhagic telangiectasia (HHT). Therefore, she was diagnosed with paradoxical cerebral embolism secondary to the pulmonary AVF without HHT. Pulmonary AVF should be considered in patients with cerebral embolism, even when presenting with spectacular shrinking deficit.