Paradoxical Emboli as a Cause of Stroke

Cerebrovascular embolic strokes are responsible for significant morbidity. 40% of strokes have no inciting cause and are thought to be the result of paradoxical emboli (PDE) passing into the arterial system by way of intra-cardiac or pulmonary vascular defects. We present two cases of PDE resulting in acute ischemic events. A 63-year-old female presented for evaluation of left upper extremity numbness. Imaging was significant for an acute right middle cerebral artery infarct and evidence of a large saddle pulmonary embolism. The patient's stroke was postulated to have been secondary to a patent foramen ovale (PFO). An 87-year-old male presented for evaluation of chest pain. The patient underwent three-vessel CABG and experienced an acute left hemispheric stroke post-operatively. Transthoracic echocardiogram demonstrated a biatrial thrombus transversing a PFO and was postulated to have been the cause. The prompt diagnosis of PDE is paramount to preventing the morbidity associated with repeat ischemic events.