ITS JUST LIKE the tortoise and the hare. A TIA is the hare and the migraine is the tortoise. TIA is a happens fast and is over fast a migraine is a slow process.,, I have had a type of vertiginous migraine for years. I have a severe case and At its worst i exhibit stroke like symptoms. the first time scared the crap outta me and i went to the ER.when i asked the doctor why this occurs he said migraines affect the flow of blood to brain very similiar in some ways to a TIA. the blood flow to the brain is compromised. in some cases i was told patients with severe migraines are diagnosed with TIA when in fact it's just the normal symptoms of a bad migraine.(its even hard for doctors to distiguinsh the two) please note that migraine suffers have silent migraines..meaning even though you don't feel the pain of a headache the blood flow is still compromised and you can exhibit the stroke like symptoms. basically a headache sufferer almost always has a headache even if they aren't feeling it. generally TIAs are a quick abrupt onset that doesnt usually last more than 5-30 minutes then just as quick the symptoms are gone. ...a migraine is usually a much slower onset that lasts longer than 30 minutes. hope that helps.....