I am now at just over 13 months post-op for retrosig removal of AN, ~3cm.
I have had continuous headaches on the surgery side after the initial steroid therapy taper down. These headaches were initially described to me as inflammation of the meninges, and my surgeons said they were part of the healing process. I have them around the clock, but they are completely relieved by a medication called Indomethacin (Indocin). I take 50mg of this every 8 hours. If I am late or miss a dose, it is 9/10 headache pain after it really sets in. I have been nauseous and in tears it's been so bad at times.
I saw the headache specialist yesterday after waiting for over 9 months to get in to see him. He diagnosed me with Hemicrania Continua. I suppose this is latin for "one-sided headache that never ends". It's clear to me after meeting with him that this is the new normal, and is no longer part of the healing process. At least it is completely relieved by Indocin, though I will be taking this LONG TERM, and it can wreck your kidneys. The docs have also described some other nerve blocking injections that I think I will try. It sounds like some here have had success with that.
It's quite depressing to have this diagnosis as a primary headache condition (Hemicrania Continua in rare cases goes into remission, but is usually not curable). I have had a rare tumor (AN) and now a rare outcome from the surgical removal of it (a neverending headache).
I just wanted to share with all of you who have a continuous bad headache on just one side, that you might try the indomethacin. It has made functioning possible for me. (It's a NSAID often used for severe arthritis long term).