Hi Neal,
I had a lot of migranes and dull headaches before surgery. My doctor did tell me that the people with headaches prior to surgery have a higher incidence of headaches after. Mine got worse. My headaches are on the opposite side of my surgery.
I've read a lot about the therories and surgical techniques suspected. I have my operating room report and all the precautions were taken. The most experienced of surgeons seem to have a percentage of post-op headaches from what I've picked up from this site and from my own experience. I've also noticed from this site, that different surgical approaches give different variations of headaches. Some of these variations seem harder to treat than others. (Totally non-scientific observation by me.) Research, like you said, suggests R/S has a higher percentage. All in all, it is a bit of a crap shoot even when you work the odds. Even non-AN people can get these type of chronic headaches from trauma, high fever or out of the blue.
In answer to your questions. Regarding the smaller tumors? I read the same. Never heard an explaination as to why. Burn out was brought up by one of our posters. Her neurologist said sometimes the nerve just stops firing pain signals.
The upside is that I have the same hearing (75%) as before my surgery and no facial weakness. Life is good even though a little different. With headache treatment, fairly close to normal with a little work.
Best wishes with your decision and your up-coming surgery. Thanks for your well wishes.
Janet