Detection of paradoxical cerebral embolism using transcranial doppler in a patient with infarct of undetermined cause

A 35-year-old man presented with acute aphasia and a left parietal infarction demonstrated by magnetic resonance imaging. He did not have an obvious etiology for stroke except for a patent foramen ovale detected by contrast echocardiography. A simultaneous transcranial Doppler ultrasound examination detected microbubbles in the middle cerebral artery. A deep venous thrombus was also detected. It is presumed that a paradoxical embolization occurred through a patent foramen ovale with target organ involvement demonstrated by the transcranial Doppler study. Transcranial Doppler may be used to detect paradoxical embolism in patients with acute stroke of undetermined cause.