title: Lesion patterns in patients with cryptogenic stroke with and without right-to-left-shunt.
abstract: OBJECTIVE
  Despite numerous studies, the role of patent foramen ovale (PFO) as a risk factor for stroke due to paradoxical embolism is still controversial. On the assumption that specific lesion patterns, in particular multiple acute ischaemic lesions on diffusion-weighted magnetic resonance imaging, indicate a cardioembolic origin, we compared the MRI findings in stroke patients with right-to-left shunt (RLS) and those without.
  
  
  METHODS
  The records of 486 patients with diagnosis of cerebral ischaemia were reviewed. For detection of RLS, contrast-enhanced transcranial Doppler (c-TCD) was carried out in all patients. An MRI scan of the brain was performed in all patients. Affected vascular territories were divided into anterior cerebral artery, middle cerebral artery, vertebrobasilar artery system including posterior cerebral artery, brain stem and cerebellar stroke, and strokes occurring in more than one territory.
  
  
  RESULTS
  We did not find a specific difference in neuroradiological lesion patterns in patients with RLS compared with patients without RLS. In particular, 23 of 165 patients (13.9%) with RLS showed multiple ischaemic lesions on MRI in comparison with 45 of 321 patients (14.0%) without RLS (P = 0.98). These findings also applied for the subgroup of cryptogenic strokes with and without RLS.
  
  
  CONCLUSIONS
  We found no association between an ischaemic lesion pattern that is considered as being typical for stroke due to cardiac embolism and the existence of PFO. Therefore, our findings do not provide any support for the common theory of paradoxical embolism as a major cause of stroke in PFO carriers.
authors.affiliation: Department of Neurology, Technische Universitaet Muenchen, Klinikum Rechts der Isar, Muenchen, Germany. regina.feurer@gmx.de
authors.forename: R
authors.initials: R
authors.lastname: Feurer
authors.forename: S
authors.initials: S
authors.lastname: Sadikovic
authors.forename: L
authors.initials: L
authors.lastname: Esposito
authors.forename: J
authors.initials: J
authors.lastname: Schwarze
authors.forename: A
authors.initials: A
authors.lastname: Bockelbrink
authors.forename: B
authors.initials: B
authors.lastname: Hemmer
authors.forename: D
authors.initials: D
authors.lastname: Sander
authors.forename: H
authors.initials: H
authors.lastname: Poppert
mesh_terms: D000368:Aged; D001921:Brain / Q000098:blood supply* / Q000503:physiopathology*; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000209:etiology*; D016009:Chi-Square Distribution; D019320:Embolism, Paradoxical / Q000150:complications* / Q000000981:diagnostic imaging; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications* / Q000000981:diagnostic imaging; D006801:Humans; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D012189:Retrospective Studies; D012307:Risk Factors; D014463:Ultrasonography