title: Embolic lesion pattern in stroke patients with patent foramen ovale compared with patients lacking an embolic source.
abstract: OBJECTIVE
  Multiple acute ischemic lesions on diffusion-weighted magnetic resonance imaging (DWI-MRI) are thought to be of embolic origin. However, in several patients with multiple ischemic lesions on DWI-MRI, no embolic source was detected, despite a thorough clinical work-up. Stroke etiology in such cases is then classified as cryptogenic. In other patients, a potential embolic source is limited to a patent foramen ovale (PFO) that may act as an embolic source of unsure relevance. We therefore examined the prevalence of the multiple-lesion pattern in patients with cryptogenic stroke compared with patients with PFO.
  
  
  METHODS
  We screened 650 stroke patients by DWI-MRI. For the subsequent evaluation, we excluded patients with a cardiac embolic source other than PFO, symptomatic carotid artery disease, and other apparent stroke causes, such as dissection or vasculitis, and patients whose diagnostic work-up was incomplete. For the remaining 106 patients, we found DWI lesions in 73, who were subjected to further evaluation.
  
  
  RESULTS
  There were no differences in the occurrence of the multiple-lesion pattern in patients with cryptogenic stroke compared with patients with PFO, either for the entire group or for the subgroup of young stroke patients who were <50 years old. Patients with PFO showed a significantly higher incidence of multiple lesions in the posterior circulation.
  
  
  CONCLUSIONS
  The multiple-lesion pattern on DWI-MRI is not uncommon, even when extensive testing does not reveal any embolic source. Therefore, it is not possible to discriminate between cryptogenic stroke and stroke from an assumed paradoxical embolism.
authors.affiliation: Department of Neurology, University of Giessen, Am Steg 14, D-35385 Giessen, Germany. marek.jauss@neuro.med.uni-giessen.de
authors.forename: Marek
authors.initials: M
authors.lastname: Jauss
authors.forename: Tiemo
authors.initials: T
authors.lastname: Wessels
authors.forename: Susan
authors.initials: S
authors.lastname: Trittmacher
authors.forename: Jens
authors.initials: J
authors.lastname: Allendörfer
authors.forename: Manfred
authors.initials: M
authors.lastname: Kaps
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000150:complications / Q000175:diagnosis; D016022:Case-Control Studies; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006344:Heart Septal Defects, Atrial / Q000150:complications* / Q000175:diagnosis; D006801:Humans; D020766:Intracranial Embolism / Q000150:complications* / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*