Hi Jason .....
Adding a welcome to this forum! Sorry you are having these issues at 5 years out.
Like Jan, I did not have the migraines you describe pre or post-op ..... at least not related to my AN. Many years ago I had migraines, but they had stopped long before the AN was diagnosed. I have had two retrosigmoid surgeries (one on each side ..... right side for trigeminal neuralgia 16 years ago, left side for AN removal 2 1/2 years ago ..... different doctors, different states). I also did not have the puffiness at either incision site after the initial swelling subsided.
However, my head is quite sunken in on both sides. When I push on those spots, it is quite sore, but does not bother me when I do not touch them (right side more sore than left). I am not a doctor either, so I would certainly advise you to have it checked (which you are doing with the MRI next week).
Please let us know what you find out.
Thoughts and prayers.
Clarice