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:
Tremor - essential
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:
If an essential tremor occurs in more than one member of a family, it is called a familial tremor.
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:
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:
Blood tests and imaging studies (such as a CT scan of the head, brain MRI, and x-rays) are usually normal.
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Reviewer Info: Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital; and Linda Vorvick, MD, Seattle Site Coordinator, Lecturer, Pathophysiology, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.; ADAM Health Illustrated Encyclopedia, 05/28/2008 |