I'm sorry to hear about your little one getting migraines. Yes, it sounds like a migraine. I used to get them when I was young, and it culminated in eighth grade when I was walking up the stairs in school and I was hit with such a strong migraine that I lost all the strength in my legs and lost my eyesight for a half hour. I threw up and when my vision returned, I could not bear the light. I had synesthesia.

After having an EEG and being examined by professionals, they determined that a) I needed glasses, b) stress may have had a major part to play in my migraines. It wasn't until years later that I realized that certain smells can actually trigger them!

Over the years, I have had them on occasion since then. I would definitely get an MRI and talk to the doctors about prevention. Many people that I know have had migraines that are triggered by food; but very bright light has also been known to do so. You may want to see about getting your little guy some sunglasses because the bright sun may be doing it.

I do know that there are medications out there for migraines, but I would not be too worried- I think they are only to be taken at the onset of a migraine.

ETA: MSG may very well be the culprit!