Benign essential tremor (ET) is a movement disorder most commonly characterized by shaking in the hands. 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. People with ET appear to have faulty brain circuits, but it is not yet known whether a brain abnormality is causing this movement problem.
Risk Factors
A risk factor is something that increases your chances of getting a disease or condition. 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 of ET may include:
-
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
To be considered as having ET, tremors must be related to other health conditions.
Diagnosis
Your doctor will ask about your symptoms and your medical and family history, and perform a physical exam, paying particular attention to your neurologic system. At this time, there are no special tests used to diagnose ET. But you may have blood, urine, or other tests to rule out other causes of tremulousness, such as:
-
Parkinson's disease
-
Elevated thyroid hormone
-
Low blood sugar
-
Stroke
-
Medications
Treatment
Most people with ET do not require treatment. Mild tremors may be relieved or even eliminated by simple measures, including:
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
-
Beta-blocker (propanolol), heart medication
-
Anti-seizure medications (primidone)
-
Sedatives (benzodiazepines)
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: transmits painless electrical pulses to the brain, interrupting faulty signals
-
Thalamotomy: destroys a tiny part of the brain generating the tremors
Prevention
There is no known way to prevent ET.
RESOURCES:
International Essential Tremor Foundation (IETF)
http://essentialtremor.org
WE MOVE (Worldwide Education and Awareness for Movement Disorders)
http://www.wemove.org
CANADIAN RESOURCES:
BC Health Guide
http://www.bchealthguide.org
Parkinson Society Canada
http://www.parkinson.ca
References:
Essential tremor. American Academy of Family Physicians website. Available at: http://familydoctor.org/807.xml?printxml. Accessed August 4, 2005.
Essential tremor. Mayo Clinic website. Available at: http://www.mayoclinic.com/invoke.cfm?id=DS00367. Accessed August 4, 2005.
Introductory packet. International Essential Tremor Foundation website. Available at: http://essentialtremor.org/. Accessed August 4, 2005.
Jacques D, Young R, Essential tremor. International Radiosurgery Support Association website. Available at: http://www.irsa.org/essential_tremor.html. Accessed August 4, 2005.
What is essential tremor? Who gets ET? International Essential Tremor Foundation website. Available at: http://essentialtremor.org/about_us/about_essential_tremor.php. Accessed August 4, 2005.
