Essential tremor Health Article

Definition

Essential tremor is a type of involuntary shaking movement in which no cause can be identified. Involuntary means you shake without trying to do so.

See also:

• Drug-induced tremor
• Familial tremor
• Tremor

Alternative Names

Tremor - essential

Causes, incidence, and risk factors

Essential tremor is the most common type of tremor. In general, tremors occur when there is a problem with the nerves supplying certain muscles. The specific cause for essential tremor is unknown. However, some research suggests that the cerebellum, the part of the brain that controls muscles movements, does not work correctly in patients with essential tremor.

Essential tremors can occur at any age but are most common in people older than 65. There are several different types of essential tremor, including:

• Essential tremor with head tremor
• Young-onset essential tremor (essential tremors that start at an earlier-than-usual age)

If an essential tremor occurs in more than one member of a family, it is called a familial tremor.

Symptoms

The tremors are usually most obvious in the hands, but may affect the arms, head, eyelids, or other muscles. The tremors rarely affect the legs or feet. People with essential tremors may have trouble holding or using small objects such as silverware or a pen.

The shaking usually involves small, rapid movements -- more than 5 times a second.

The tremors may:

• Occur when you move (action-related tremor), and may be less noticeable with rest
• Come and go, but generally get worse as you age
• Get worse with stress, caffeine, and certain medications
• Not affect both sides of the body the same way

Signs and tests

Your doctor can make the diagnosis by performing a physical exam and asking questions about your medical and personal history.

A physical exam will show shaking with movement. There are usually no problems with coordination or mental function.

Further tests may be needed to rule out other reasons for the tremors. Other causes of tremors may include:

• Alcohol withdrawal
• Cigarette smoking
• Hyperthyroidism
• Pheochromocytoma
• Too much caffeine
• Use of certain medications
• Wilson's disease

Blood tests and imaging studies (such as a CT scan of the head, brain MRI, and x-rays) are usually normal.