I had the gamma knife done five years ago. I was totally pain free the same night and it stayed that way for six months. Then, I got numbness from the corner of my right eye to my chin. It has never gone away but it is NOT pain. It's numbness and pressure not unlike sinus pressure.
They tell me after 5 years the TN can come back but I'm hoping I'm an exception. The procedure itself only involves a small amount of pain when they attach the frame with screws, but after TN it's not much to take.
The percentage of patients who get the numbness is low so I still think it's the best way to go.
My Dr. says if the TN does return then my only option is an MVD because the nerve already has numbness. Well, I'll cross that bridge when I come to it.
By the way, you should be awake for the procedure. A friend had the GK when under sedation and she ended up with AD. Hope I've been some help.
Best Regards, metal1