"Essential tremor describes a chronic, progressive, predominantly bilateral upper limb, action tremor syndrome, present without parkinsonism, dystonia and ataxia. Essential tremor associated with other 'soft' neurological signs is known as essential tremor plus."
"Essential tremor is one of the most common movement disorders. Its prevalence increases with age, and is estimated to affect up to 5% of the population over the age of 65 years 1. However, the condition can also be seen in younger patients, including in the paediatric demographic, albeit rarely 1. There is thought to be either no gender predilection or a slight male predominance 1."
"The exact aetiopathogenesis of essential tremor is yet to be fully elucidated. The primary hypothesis is that there is dysfunction in the cerebello-thalamo-cortical circuit 2,4,5. There is also thought to be a strong genetic component to essential tremor, given a family history may be present in up to half of all patients, however, no genes have yet been implicated 1."
"enhanced physiologic tremor (e.g. due to hyperthyroidism)"