That's a new one on me. The only preaura I've heard of relates to epilepsy (and I asume that would have been checked out/eliminated). Your description does make me wonder though, about the cause/effect (and I'm just thinking aloud here); is the preaura caused by the episode coming on, or is the episode the result
of the preaura? It almost sounds like a chemical imbalance (like
depression) causing the aura, which in turn leads to the migraine. But I gotta figure you've been through all the migraine prophylactics and antidepressants....
Is your doctor a migraine
specialist? There are directories -- I think I sent you one. When mine were at their worst, I would have made the trip out of state to see one/more (turned out there was one in my area) but I don't recall if you've been down that road either...
Looking for migraine doctors?
Another thought just occurred to me... Have you had these preauras from the get-go, or are they something that's developed/evolved after a while?