Anecdata: I have observed that my migraines come in cycles with the subjective experience of not having slept. I know I've slept, because I have long stretches

Anecdata: I have observed that my migraines come in cycles with the subjective experience of not having slept. I know I've slept, because I have long stretches of unconsciousness as confirmed by the clock on my nightstand. But I don't feel like I've slept. Then I'll have a migraine and a few nights of really great (subjectively) sleep before the cycle starts over again. It's like there's something building up in my brain that's blocking real REM sleep, and cleaning it out results in the subjective experience of a migraine.