Paradoxical embolism to the basilar apex associated with May-Thurner syndrome

Embolic occlusion of intracranial vessels can be caused by material arising proximally, most commonly from the heart, the aorta, or the carotid or vertebral arteries, and rarely from systemic veins. May-Thurner syndrome is an uncommon condition in which there is impaired venous return because of compression of the left common iliac vein by the overlying right common iliac artery, resulting in iliofemoral deep venous thrombosis.

To describe a young patient with presumed paradoxical embolism to the basilar apex associated with a patent foramen ovale and May-Thurner syndrome.

Single case report.

A 16-year-old girl with a history of bulimia and oral contraceptive use had a "top of the basilar" syndrome. She was found to have a patent foramen ovale on transthoracic and transesophageal echocardiography. Magnetic resonance venography of the lower extremities revealed May-Thurner syndrome. Antiphospholipid antibodies (antiphosphatidylserine, anticardiolipin, and antiphosphatidyl-ethanolamine), factor V Leiden mutation by polymerase chain reaction, and homocyst(e)ine levels were normal. Anticoagulation with intravenous unfractionated heparin sodium followed by warfarin sodium was used, resulting in resolution of her neurologic deficits.

Deep venous thrombosis is notorious for its variable clinical manifestations and the potential dire consequences of a missed diagnosis. Physicians caring for patients with presumed paradoxical embolism should assess for May-Thurner syndrome.