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Definition

Benign essential tremor (ET) is a movement disorder most commonly characterized by shaking in the hands. It occurs in as much as 10% of people over the age of 60. It may also cause shaking of the head, voice, arms, and trunk, and less often, of the legs and feet. Two types of tremor are common with ET:

  • Postural tremor—shaking in certain positions only, such as with arms outstretched
  • Kinetic or action tremor—shaking that gets worse during activities, such as eating or shaving

In some cases, ET can be socially isolating. It may interfere with normal daily activities, such as writing or speaking. If so, contact your doctor for an evaluation.

Causes

The cause of ET is unknown. However, it does run in families. When inherited, it is often called familial tremor. Children of parents with ET have a 50% chance of inheriting the condition.

In cases where there is no family history of tremor, other factors, such as toxins, may play a role, though this is far from clear. It is thought that essential tremor arises from abnormalities of specific circuits in the brain. This is an area that researchers are studying.

The Nervous System

Nervous system posterior 3D
Benign essential tremor occur when faulty nerve cells (or circuits) in the brain send abnormal signals to muscles.
© 2009 Nucleus Medical Art, Inc.

Risk Factors

Family history of tremors is the only known risk factor for ET. Although the condition may occur at any age, it is more likely to occur in people older than 40 years old.

Symptoms

ET is generally not serious, but its severity may vary and worsen over time. Symptoms may include:

  • Tremor that occurs when standing or moving the limbs, but not usually at rest
  • Uncontrollable, rhythmic, up-and-down movement
  • Shaking in hands, arms, head, voice, trunk, legs, or feet on both sides
  • Shaking only in certain positions or during activity
  • Trouble with fine motor skills, such as drawing, sewing, or playing an instrument
  • Shaking that gets worse from caffeine, stress, fatigue, or heat
  • Hearing loss]]> (Some cases are associated with hearing loss.)
  • Problems with social, functional, or occupational abilities (More severe cases interfere with these abilities.)

To be considered as having ET, tremors must not be related to other health conditions.

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Diagnosis

Your doctor will ask about your symptoms and your medical and family history. He will also do a physical exam, paying particular attention to the central nervous system. At this time, there are no special tests to diagnose ET. But, you may have blood, urine, or other tests (eg, MRI]]> ) to rule out other causes, like:

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Treatment

Most people with ET do not require treatment. Mild tremors may be relieved or even eliminated by simple measures, including:

  • Staying well-rested
  • Avoiding caffeine
  • Avoiding stimulants often found in over-the-counter medications, like cold remedies
  • Avoiding temperature extremes

Talk to your doctor about any medications that may be contributing to your symptoms. If your symptoms are troubling, the following treatment options may be helpful:

Medication

Surgery

In rare cases where tremors are very disabling and medications don’t help, surgery may be an option. Two approaches are possible.

  • Deep brain stimulation (DBS)—transmits painless electrical pulses to the brain, interrupting faulty signals.
  • Thalamotomy—destroys a tiny part of the brain generating the tremors (less commonly performed than DBS)

Prevention

There is no known way to prevent ET.