I'm not familiar with the correct terminology (is there a test on this tomorrow??) for most any of the stuff anymore, but I get migraines similar to what you describe, but as an "aura" that comes on prior to the headache. I'd describe the "numb ... left arm" you describe as more of an "upper shoulder" kind of thing with mine. It might be 30 minutes worth, or a couple hours. It varies. Then the headache comes, and it'll be a whopper, all on one side. Then there's what I call a lupus headache, that tries to rival the migraine in intensity, but they almost always involve both sides of the brain. They might "ramp up" fast, or come on slow. It varies. Those are almost always preceded with an extra-special dosing of "brain fog" prior to their arrival. Then there's the tension headache that doesn't like to be ignored... Beyond that, I'm not much help. I go to the neurologist on the 8th of Feb, so I might get more info from him, since he'll be doing all sorts of neat tricks with needles and electrical "stimulation" on me oh boy...
Did the doc double-check your heart during the exam today?
"There but for the grace of God, go I."
"... His mercy endureth for ever."