Prevalence of Patent Foramen Ovale Detected by Transcranial Color Coded Duplex Sonography in Cryptogenic Stroke Patients

Background/Objectives:Contrasttranscranialdopplerhasbeenusedfordetectionofright-to-left shunts,suchasthepatentforamenovale(PFO). MaterialsandMethods:Allconsecutivepatientswithcryptogenicbraininfarctionadmittedtothe WalterMackenzieHospital,Canada,during2003-2004,enrolledina prospectivestudy.Cryptogenic strokewasdeterminedusinga standardbatteryofdiagnosticinvestigations.Transcranialcolorcoded duplexsonography(TCCDS)withsalinecontrastwasperformedwithanHPSono5500,USAdevice anda 4MHzlinearprobe.Themiddlecerebralarterywasinsonatedata 50-55mmdepththrougha transtemporal window. Microbubble signals were recorded during normal respiration and Valsalva maneuver. Results:114patients(70females,44males)withcryptogenicstrokehadcontrastTCCDSdone.PFO wasdetectedin41patients(30females,11males;35.9%).Intheoverallstudygroup,femaleswere more preponderant to have PFO, however the difference was not significant (P=0.053). The frequency ofPFOwasnot significantlydifferentbetweenage groups =<45yearsand>45years (P = 0.96). Conclusion: PFO detected by TCCD is an age independent factor in cryptogenic stroke, and its detectionismorefeasiblewithValsalvamaneuver.