Essential Tremor
Essential tremor (ET) is a disorder of the nervous system that causes shaking. The hands are most commonly affected, but ET can also cause the head, voice and torso to tremble. It can affect people of any age but is most common in those older than 65.
ET can remain mild, or it can get progressively worse over time and might spread to other parts of the body. An estimated 10 million Americans have ET.
Symptoms
ET commonly occurs when a person is moving, especially when the hands are extended; it might cause problems with such tasks as writing, drawing, applying makeup or using silverware. The hands might shake; the voice might quiver; and the head might move up and down or side to side.
ET is most likely to be noticed in the hands and forearms. There are often small movements taking place four to 12 times per second.
Symptoms might get worse during times of stress or fatigue.
The trembling might be more noticeable on one side of the body than on the other, and symptoms might improve when the patient drinks a small amount of alcohol.
Causes
ET is hereditary in more than half of cases; a person is most likely to have essential tremor if a parent or another close family member has it. However, not everyone with a close relative who has ET develops it.
The exact cause of ET is not known. Although it is thought that abnormal brain function might contribute to ET, this has not been confirmed, and no specific gene for ET has been identified.
Treatment
Treatment for ET is necessary when it causes embarrassment or otherwise affects a patient’s quality of life. Physical therapy to improve strength and coordination might bring about improvement, and occupational therapy might help a patient better manage everyday tasks. Other options include oral medications, injections or deep-brain stimulation surgery.
