My fellow moderator, Phyl (posting under the screen name 'ppearl214') had a smallish AN successfully treated with radiation in 2006. She also had the Chiari malformation. I'm sure Phyl will be along soon to add whatever information she has. Meanwhile, consider yourself among friends, here. We'll support whatever treatment decisions you make and try to offer you as much help and information as we can to get you through this medical challenge.
Hi JB and welcome.
As Jim noted, yes... I have AN and CM1 as well. Anissa, here on this site, also has AN and CM1 as well as Denise noted above.
I did have radiation (Cyberknife) done on my AN just over 4 years ago (dr's now deem my AN journey as a "done deal") and we monitor the CM1 closely. My slippage has not progressed over time but I am asymptomatic with the migraines, extremity weakness, etc. There is a woman here (Raydean) who's daughter has CM1 (but not AN) and her daughter's CM1 journey has been most difficult. Raydean is a lovely woman and has shared much about her daughter's CM1 journey.
For the CM1 journey, it is imperative that you find a CM1 specialist. There are many neurosurgeons that say "oh, sure... I can handle your CM1 as well...". Don't be fooled. It is a very rare condition (much like AN's) and not any old surgeon can handle it. I know of CM1 specialists on the east coast and N. CA that do have a specialty in CM1 and not sure where you are located. Glad to share info if I can.
Suggestion is to also go to the forum homepage, do a "search" option for "chiari 1" and you will see many of the discussions over the years regarding AN's and CM1 combined. My inbox is always open and glad to help if I can.