Paradoxical brain embolism in an acute stroke.

Paradoxical embolism to the cerebral circulation is often difficult to diagnose clinically. We report a case that illustrates the usefulness of transesophageal echocardiography in the detection of paradoxical embolism. An 84-year-old woman presented with bilateral hemispheric strokes. Despite the presence of atrial fibrillation, clinical suspicion of paradoxical embolism led to further investigation. An underlying lower limb deep venous thrombosis was found, lung scintigraphy showed pulmonary embolism, and a right-to-left shunt was detected using contrast-transcranial Doppler ultrasound even without the Valsalva maneuver. Transesophageal echocardiography confirmed a mobile 4-cm serpiginous thrombus wedged into a patent foramen ovale, extending from the right into the left atria. Multiple imaging modalities were used, allowing rapid diagnosis of paradoxical embolism, with an underlying DVT as the mechanism of stroke. Of all the investigations, visualization with TEE proved crucial in confirming the diagnosis.