Right-to-left shunt due to patent foramen ovale is a well-established risk factor for ischemic stroke, especially in young
subjects and in patients with cryptogenic stroke. We report a detailed method for the diagnosis of a right-to-left shunt by
means of transcranial Doppler as established at a recent consensus conference, and review the literature on the indications
for the test.
Key words Stroke - Migraine - Foramen ovale, patent - Transcranial Doppler
Received: 25 June 2001 / Accepted in revised form: 6 November 2001