title: Is stroke a paradoxical embolism in patients with patent foramen ovale?
abstract: OBJECTIVE
  Purpose was to assess the stroke mechanism in patients with patent foramen ovale (PFO).
  
  
  METHODS
  We reviewed the medical records of 111 stroke patients with PFO and sinus rhythm (PFO-S group), 25 with PFO and atrial fibrillation (AF) (PFO-AF group) and 67 with AF but not PFO (AF group), who had received contrast transesophageal echocardiography. The clinical and neuroradiological findings were then compared among the three groups. Deep vein thrombosis was investigated in 93 patients with PFO. We determined the number of patients with definite paradoxical embolism who met three criteria: deep vein thrombosis, neuroradiological features indicating embolic stroke, and the absence of other sources of emboli. We also evaluated those with probable paradoxical embolism who met two of the three criteria.
  
  
  RESULTS
  The PFO-S group more frequently exhibited hypercholesterolemia (p<0.0001) and lesions limited to the posterior circulation (p<0.0004), and less frequently exhibited large or cortical lesions in the anterior circulation (p=0.0008, p<0.0001, respectively), than the PFO-AF and AF groups. In the PFO-S and PFO-AF groups, other sources of emboli such as a cardiac source of emboli, cerebral artery stenosis > or =50%, or complicated atheroma in the aortic arch were identified in 72 cases (52.9%). In the 93 patients with examination for deep vein thrombosis, the definite and probable criteria of paradoxical embolism were fulfilled only in three (3.2%) and 33 cases (35.5%), respectively.
  
  
  CONCLUSIONS
  In stroke patients with PFO, not only paradoxical brain embolism through the PFO but also other causes of stroke may contribute to the development of stroke.
authors.affiliation: Cerebrovascular Division, Department of Medicine, National Cardiovascular Center, Osaka, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yasaka
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Otsubo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Oe
authors.forename: Kazuo
authors.initials: K
authors.lastname: Minematsu
mesh_terms: D017668:Age of Onset; D000368:Aged; D020771:Anterior Cerebral Artery; D002339:Carotid Arteries / Q000000981:diagnostic imaging; D002533:Cerebral Angiography; D017548:Echocardiography, Transesophageal; D004562:Electrocardiography; D019320:Embolism, Paradoxical / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006344:Heart Septal Defects, Atrial / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D020243:Infarction, Anterior Cerebral Artery / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D020762:Infarction, Posterior Cerebral Artery / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D007564:Japan / Q000453:epidemiology; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D020769:Posterior Cerebral Artery; D012189:Retrospective Studies; D012307:Risk Factors