You can have any symptoms of a migraine with or without any other symptoms. So yes, you can have visual disturbances without having a headache. I had a friend who's sole symptom of migraine was going completely blind in one eye. (Please note the visual disturbances could be caused by something else.) I've had the coldness without any other symptom.

This is just an observation - I've noticed that if I get a migraine, other people who suffer from them are very apt to have them as well. Weather (barometric changes, I think) can sometimes trigger mine. That could explain some of the migraine "outbreaks."

Penny S, I can eat anything I want when I'm not in the "zone." I'm not sure the foods have anything to do with my headaches, because I don't have any way of telling which ones I would have gotten anyway.