The spectrum of involuntary movements seen in essential tremor (ET) is limited. Jaw tremor is one such movement. The prevalence and clinical correlates of jaw tremor have not been studied in detail.

The symptom, which sees the hands, jaw and legs shake uncontrollably ... noradrenaline acts as an amplifier, which increases tremor intensity in the brain’s movement area.

At the age of 52 years, a man had begun to exhibit jaw tremor, decreased vocal volume, reduced facial expression and muscle pain, all of which suggested a diagnosis of Parkinson disease (PD).