I cannot say I have this symptom but I have lots of twitching in my facial muscles so they are definitely effected. I also mentioned in another post that I read in a medical journal about a model who came in to the hospital/doctor complaining that she could not smile. She was diagnosed with a mild form of GBS, treated, and completely recovered. I have also known two people with bells palsey who temporarily had trouble with facial muscles. My situation, the model's situation, and the people I've known with bells palsey do not mean that you have what I or they have but it does show that non-sinister things can effect the facial nerves and muscles. People here complain of fatigue in muscle that twitch so I cannot think of a logical reason why the same thing cannot happen to any muscle being effected by what is labeled "bfs."I also think TMJ can cause facial muscle fatigue. My dad is a major stressor and complains he has trouble chewing certain things. He has complained about this for many years but no one but him notices a problem. He only mentions it every now and then so I'm guessing it is just fatigue from tensing his facial muscles too much. Maybe those with TMJ could shed more light on this issue.