I'm not quite sure either. I do know before the tmj started I was starting to speak slower b/c the faster I spoke the more tired or fatigued my facial muscles would become and then my face would start to ache. I was also having problems pronouncing certain words and would search for alternatives just to avoid trying to say them. My guess would be it could be either since both are indicative of muscle control issues with the tongue and other facial muscles. I saw your other post - and while it may be that most of what you are experiencing is tmj related - it can be just as easy to blame every symptom on tmj just as well - so its not a bad a idea to see a neuro and rule out other possibilities - many tmj sufferers do end up seeing several various specialists over time since tmj symptoms can be so widespread and varied.