Migraines in general are weird. It's rare[1], but I can occasionally tell when a severe migraine is about to occur because rooms feel too big. I walked into my bathroom a few days ago (which is about 2mx2m/6'x6'), and each wall seemed about 2 feet longer than it should, and the far corner looked about 3 feet too far away (it was more a feeling than a visual disturbance - it's hard to describe). I felt _small_, which is a really odd feeling when it comes on suddenly. About an hour later, I had a severe migraine.
I'm assuming it's a subtle form of Alice in Wonderland syndrome[2].
[1] I get regular migraines, but I can only remember this happening a few times, possibly because it's fairly subtle
Oh wow, I get that semi-regularly (couple times a year maybe) when I'm sitting with in front of my HTPC TV with my wireless keyboard. Everything feels far away, and I feel tiny and dissociated from my actions. Not subtle at all. Standing up snaps me out of it, but it feels kind of cool so usually I let it persist.
I don't think it's ever preceded any kind of headache, but I've never tried to correlate the timing with anything else. I'll have to pay more attention when it happens again.
I've never had a migraine but I've definitely had that feeling like the room was too big. I think it only happened once or twice as a kid from a fever or something.
I had that as a kid for a while; when it reached its peak, I ended up in hospital with meningitis. From that period, I distinctively remember feeling small and the room walls and ceiling receding somewhat, and also some weird stuff with colors - I could focus on the visual noise I saw (kind of like the noise you get in a digital camera in low-light condition), and focusing on that would trigger the feeling of the world expanding / me shrinking. All of this only happened at night.
I'm assuming it's a subtle form of Alice in Wonderland syndrome[2].
[1] I get regular migraines, but I can only remember this happening a few times, possibly because it's fairly subtle
[2] https://en.wikipedia.org/wiki/Alice_in_Wonderland_syndrome