title: Decrease in shunt volume in patients with cryptogenic stroke and patent foramen ovale.
abstract: BACKGROUND
  In patients with patent foramen ovale (PFO) there is evidence supporting the hypothesis of a change in right-to-left shunt (RLS) over time. Proven, this could have implications for the care of patients with PFO and a history of stroke. The following study addressed this hypothesis in a cohort of patients with stroke and PFO.
  
  
  METHODS
  The RLS volume assessed during hospitalisation for stroke (index event/T0) was compared with the RLS volume on follow-up (T1) (median time between T0 and T1 was 10 months). In 102 patients with a history of stroke and PFO the RLS volume was re-assessed on follow-up using contrast-enhanced transcranial Doppler/duplex (ce-TCD) ultrasound. A change in RLS volume was defined as a difference of ≥20 microembolic signals (MES) or no evidence of RLS during ce-TCD ultrasound on follow-up.
  
  
  RESULTS
  There was evidence of a marked reduction in RLS volume in 31/102 patients; in 14/31 patients a PFO was no longer detectable. An index event classified as cryptogenic stroke (P < 0.001; OD = 39.2, 95% confidence interval 6.0 to 258.2) and the time interval to the follow-up visit (P = 0.03) were independently associated with a change in RLS volume over time.
  
  
  CONCLUSIONS
  RLS volume across a PFO decreases over time, especially in patients with cryptogenic stroke. These may determine the development of new strategies for the management in the secondary stroke prevention.
authors.affiliation: Department of Neurology, Justus Liebig University, Giessen, Germany. Christian.Tanislav@neuro.med.uni-giessen.de
authors.forename: Christian
authors.initials: C
authors.lastname: Tanislav
authors.forename: Manfred
authors.initials: M
authors.lastname: Kaps
authors.forename: Marek
authors.initials: M
authors.lastname: Jauss
authors.forename: Erwin
authors.initials: E
authors.lastname: Stolz
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Pabst
authors.forename: Max
authors.initials: M
authors.lastname: Nedelmann
authors.forename: Mathias
authors.initials: M
authors.lastname: Grebe
authors.forename: Frank
authors.initials: F
authors.lastname: Reichenberger
authors.forename: Jens
authors.initials: J
authors.lastname: Allendoerfer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D054092:Foramen Ovale, Patent / Q000473:pathology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D055502:Secondary Prevention; D020521:Stroke / Q000473:pathology*