Prevalence and characteristics of right-to-left shunt in migraine with aura: a survey on 120 Italian patients.

Many lines of research have suggested a relationship between migraine with aura (MA) and patent foramen ovale. Right-to-left shunt (RLS) of blood might explain both the occurrence of MA attacks, as well as the increased risk of ischaemic stroke in these patients. We evaluated the prevalence and the characteristics of RLS in a series of 120 MA patients, who were studied with contrast-enhanced Transcranial Doppler examination. We found RLS in 61 of them. A latent RLS was found in 28%, a permanent RLS in 72%, a shower-curtain pattern was detected in 52% of the studied patients.