HI Peggy!
I had FSR, not GK, so things might be slightly different. I don't know. For what it's worth here are my thoughts on this. Others will probably give you a better answer and more GK related.
IT all depends on how much it is pressing on the brain stem. In general terms, swelling is not always present after treatment. I had it, others didn't. In my case, it had some effects, like an increase in existing symptoms, louder tinnitus and some extra hearing loss, and some short sharp pains behind the ear. However, this lasted for a limited time, and eventually the symptoms returned to 'normal', ie. pre treatment levels. All, except the hearing, still down and not likely to improve. I didn't have any problems with balance, as my balanc was already compromised years ago and the brain compensated for it. Havening swelling didn't make any difference to that, at least not to any significant level. I didn't notice.
When the tumour shrank back it seemed, the nerves relaxed a little again, so that gave me some other slight problem, all temporary and not significant. Basically, all the possible symptoms are light in general.
Of course there are two points one must say at this stage: 1) it all depends on the size and how much the AN is pressing on the brain stem to start with, and 2) we all react differently, so maybe none of the above will be your case, or all of them, or worse. Best thing to do is to talk to your radiosurgeon and ask him those questions, they will be able tot ell you what the possibilities are of problems due to swelling.
Hope this helps... Good luck tomorrow!
Ciao, Lorenzo