Dear Anastasia,
I had no idea that english was your second language, you speak it so well! I have heard stories of other people who had clear MRI's, but clearly had TN Type 1. In some cases, the doctor will still recommend an MVD, and they will often find a vein when they actually get into the brain and look around. It is truly up to your neurosurgeon to make that call, after weighing all other alternatives.
Hope this helps,
Lily