What is the best treatment for dystonia?

My mom has been having increasing facial dystonia. No one seems to be able to diagnose it except to say that it’s a sign of her worsening dementia. I’m not a doctor, but it seems to be Meige syndrome. She rapidly blinks her eyes and clenches her teeth. Can’t open her eyes sometimes. This whole process happens every few seconds some days. Her doctor thinks it may be a side effect of taking antipsychotics, so we are taking her off Donepezil. I’d like to find someone that will calm her episodes down. Does anyone have experience with this? Is Valium a good option? None of the doctors she’s seen or the staff at her mc facility seem to know what’s going on with her.