The majority (90%) of strokes that occur annually in the United States are ischemic. PFO is not considered a primary cause of stroke. Cardioembolic events account for 19% and carotid disease accounts for 15% of ischemic strokes; the remainder is cryptogenic. Approximately 40% of cryptogenic ischemic strokes are attributed to PFO. PFO can be detected in 10% to 15% of the population by transthoracic echocardiogram. Autopsy studies show a prevalence of PFO of approximately 26%.1
A number of pathologic manifestations of PFO have been recently identified, including paradoxical systemic embolism. Neurologic decompression illness (eg, in divers, high-altitude pilots, and astronauts) and migraine headache with aura also have been associated with PFO but are not common findings.2-4 Most patients with PFO, however, remain asymptomatic because under normal physiologic conditions, PFO allows a small amount of left-to-right shunting without causing significant hemodynamic change.3 consequently, neurologic deficits associated with PFO—such as those seen in this case—are rare.
Differential diagnoses for this patient’s presentation that were ruled out include intracranial or extracranial thrombosis; carotid dissection; and coagulopathies, such as antiphospholipid antibodies.5
Management of PFO
There are currently 3 primary options for management of PFO6:
• Medical treatment with anticoagulation or antiplatelet therapy
• Surgical closure
• Percutaneous closure
A TEE shows via doppler the blood flow from the right atrium to the left atrium via a septal defect.
In a study that compared aspirin(Drug information on aspirin) with warfarin(Drug information on warfarin) in the prevention of recurrent cryptogenic ischemic stroke, there was no significant benefit shown in either group.7
Although there are currently no randomized clinical trials comparing these 3 treatment methods, closure of PFO appears to have clear benefits over medical therapy in select patients.5 Many studies report that transcatheter percutaneous PFO closure is safe and effective, with efficacy that ranges from 86% to 100%.7 The procedure is simple, requires only overnight observation, and has replaced surgical closure in all but rare instances.8