Hi Catlover,
I am a little confused. If it was 8mm, and it grew 4mm, wouldn't that make it 12mm, or 1.2 cm?
Anyway, 1.2 or 1.6 cm is still small, or just barely medium. You can probably watch and wait another 6 months, which is tempting, since you seem to have no symptoms at the moment. If you do have treatment, you could also consider radiation. The Gammaknife machine was invented in Sweden, so I think there is probably one there.
If you do have surgery, you will not die, they will open the correct side of your head, and you won't have a stroke. The first few days you will not feel too good, and you might have some facial, balance, or hearing issue afterwards. By most accounts on this forum, SSD is not that difficult to deal with. With an AN your size, you would not be expected to have any long term side effects, but you might have some temporary issues for 1-6 months. All in all, not a bad outlook.
It does help to find a good experienced place to get treatment, and a doctor who has treated ANs before. There have been some discussions about various locations in Europe, if travelling is an option for you.
Hopefully you can watch and wait again, and we will hear from you in another 6 months. If not, you can do some research on this forum and elsewhere, and find a good treatment option that works well for you.
Wishing you the best,
Steve