When should you suspect that palatal tremor could be a functional neurologic disorder?  

The late Dr. Hallett and others have suggested that essential palatal tremor or myoclonus is largely functional, based upon the appropriate history of variability and entrainment, plus, in some cases, electrophysiologic data as well. As a general rule, functional disorders should be diagnosed b...

Essential palatal myoclonus (also called essential palatal tremor) is idiopathic, often considered functional (psychogenic) in many cases, and typically involves rhythmic contractions of the tensor veli palatini muscle, whereas non-essential (symptomatic) palatal myoclonus is secondary to identifiab...