Cardiologist hypophysised may have a pfo as have a lot of migraine aura. i have had 4 previous echos but no pfo seen.i have not had bubble test as cardiologist said no to cardio investigation but being refered to neurologist or migraine specialist?

Possible or probable: It's common to miss a PFO on a routine echo. A 2D echo with bubble study, or even more specifically for Migraine with aura or warning of stroke/TIA, a digital TCD with bubble study gives a much more definitive answer as to the presence or absence of a PFO. If concerned about a TIA, hypercoagulable studies should also be performed to assure no propensity for clotting. Agree with Neurological workup