title: Cryptogenic stroke and patent foramen ovale: clinical clues to paradoxical embolism.
abstract: BACKGROUND
  Patent foramen ovale (PFO) is an independent risk factor for cerebral infarction. Since ~25% of the population have a PFO, the simple association of PFO with stroke is not enough to establish the diagnosis of paradoxical embolism. We evaluated possible clinical clues to the diagnosis of paradoxical embolism.
  
  
  METHODS
  Among patients with cryptogenic ischemic stroke (CS) who were investigated for a right-to-left shunt (RLS), we compared clinical, coagulation and biochemical parameters in patients with PFO versus without PFO.
  
  
  RESULTS
  Among 1689 new patients referred for TIA/non-disabling stroke between 2001 and 2007, 175 with cryptogenic stroke (CS) were investigated for RLS by transcranial Doppler (TCD) bubble studies; 89 (5.5%) with positive TCD had a PFO confirmed by TEE. In multivariate logistic regression, a history of DVT or pulmonary embolism (OR, 4.39; 95% CI, 1.23-15.69; p=0.023), prolonged travel (OR, 8.77; 95% CI, 1.775-43.3; p=0.008) , migraine (OR, 2.30: 95% CI, 1.07-4.92; p=0.031), a Valsalva maneuver preceding the onset of focal neurological symptoms (OR, 3.33; 95% CI, 1.15-9.64; p=0.026) and waking up with stroke/TIA (OR, 4.53, 95% CI, 1.26-16.2; p=0.018) were independently associated with PFO-associated cerebrovascular events. Patients with PFO had higher plasma total homocysteine levels than patients without PFO (8.9+/-3 versus 7.9+/-2.6 micromol/L respectively; p=0.021).
  
  
  CONCLUSIONS
  A history of DVT or pulmonary embolism, migraine, recent prolonged travel, sleep apnea, waking up with TIA or stroke or a Valsalva maneuver preceding the event are clinical clues to the diagnosis of paradoxical embolism among patients with CS.
authors.affiliation: Eskisehir Osmangazi University, Department of Neurology, Eskisehir, Turkey. ozcan_99@yahoo.com
authors.forename: A Ozcan
authors.initials: AO
authors.lastname: Ozdemir
authors.forename: Arturo
authors.initials: A
authors.lastname: Tamayo
authors.forename: Claudio
authors.initials: C
authors.lastname: Munoz
authors.forename: Bryan
authors.initials: B
authors.lastname: Dias
authors.forename: J David
authors.initials: JD
authors.lastname: Spence
mesh_terms: D000328:Adult; D001780:Blood Coagulation Tests / Q000379:methods; D019320:Embolism, Paradoxical / Q000150:complications* / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications*; D006710:Homocysteine / Q000097:blood; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000150:complications*; D017585:Ultrasonography, Doppler, Transcranial; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D006710:Homocysteine; D014805:Vitamin B 12