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

Background/ Contrast transcranial doppler has been used for detection of right-to-left shunts, such as the patent foramen ovale (PFO). All consecutive patients with cryptogenic brain infarction admitted to the Walter Mackenzie Hospital, Canada, during 2003-2004, enrolled in a prospective study. Cryptogenic stroke was determined using a standard battery of diagnostic investigations. Transcranial color coded duplex sonography (TCCDS) with saline contrast was performed with an HP Sono 5500, USA device and a 4MHz linear probe. The middle cerebral artery was insonated at a 50-55 mm depth through a transtemporal window. Microbubble signals were recorded during normal respiration and Valsalva maneuver. 114 patients (70 females, 44 males) with cryptogenic stroke had contrast TCCDS done. PFO was detected in 41 patients (30 females, 11 males; 35.9%). In the overall study group, females were more preponderant to have PFO, however the difference was not significant (P=0.053). The frequency of PFO was not significantly different between age groups =<45 years and >45 years (P = 0.96). PFO detected by TCCD is an age independent factor in cryptogenic stroke, and its detection is more feasible with Valsalva maneuver.