tried different painkillers and muscle relaxers, none worked.
my doctor had one theory. It usually happened after physical activity, particular strain to the neck. my MRIs are really weird and show lots of lymph like nodes. he thinks its possible that the circulation doesn't work properly and doesn't return from my head area as it should, could be why the problem trips off. Birthmarks are deformed nerves afterall, wrong messages being sent.
i'm just glad it hasn't happened in a while.
It could just be a coincidence, but i have had no problems since my gallbladder was removed (had gallstones probably about the same time the problem started) and there are lymph glands in the neck area I THINK that are affected by that region.
But, i also try my best to avoid situations that i know might trigger it off.