Paradoxical brain embolism from thrombus associated with vena caval filter in a patient with cancer.

A 71-year-old man experienced sudden onset of hemiparesis and aphasia. He had a 4-month history of gallbladder cholangiocarcinoma, complicated with a postoperative deep-vein thrombosis (DVT) that necessitated a vena caval filter placement. Diffusion-weighted magnetic resonance imaging of the brain showed multiple hyperintense foci. Magnetic resonance spectroscopy was compatible with cerebral infarction. Abdominal computed tomography showed a thrombus in the inferior vena cava extending through the filters. A transcranial Doppler bubble study revealed the presence of a right-to-left shunt. Paradoxical cerebral embolism must be considered in patients with DVT who have new onset neurologic deficits even in the presence of a caval filter.