Clandestine,

Sounds a lot like what I am dealing with. I have been dealing witht he HA's going on 4 yrs now and have been to numerous neurologist etc....

told I have migraines triggered by head injury but aside from meds they seem not to know of any treatments or much as to my this happens.

My HA's are triggered by weather changes, stress plays a part I think and neck related problems.

I feel completely drained afterwards and get some relief from migraine rescue meds but they are $$$$.

Exercise increases my chance and I beleive it has something to do with blood flow\pressure issues,

I hope things improve for you and me but I am giving up hope at this point