Essential tremor

Alternative names:

tremor - essential

Definition:

A neurologic disorder involving tremors (shaking) that are typically elicited with activity and purposeful movement, and do not have an identifiable cause.

Causes, incidence, and risk factors:

Essential tremor affects about 6 out of 100,000 people. It is the most common form of tremor. If an essential tremor occurs in more than one member within a family group it is termed a familial tremor. Tremors occur at any age but are most common in older people.

An essential tremor is a relatively benign condition affecting movement and/or voice quality but with no other effects. It involves a rhythmic, moderately rapid tremor of voluntary muscles. Purposeful movements may make the tremors worse. There may be difficulty holding or using a small object (such as eating or writing utensils). Emotional stress may also increase the tremors. Over time, the tremors may affect the hands, arms, head, voice box (larynx), eyelids, or other muscles. An essential tremor rarely involves the legs or feet. The cause is unknown. No structural or other lesions have been identified.