Essential tremor (ET) is a nerve disorder characterized by uncontrollable shaking, or "tremors," in different parts and on different sides of the body. Areas affected often include the hands, arms, head, larynx (voice box), tongue, and chin. The lower body is rarely affected.
ET is not a life-threatening disorder, unless it prevents a person from caring for him or herself. Most people are able to live normal lives with this condition -- although they may find everyday activities like eating, dressing, or writing difficult. It is only when the tremors become severe that they actually cause disability.
What Causes Essential Tremor?
The true cause of essential tremor is still not understood, but it is thought that the abnormal electrical brain activity that causes tremor is processed through the thalamus. The thalamus is a structure deep in the brain that coordinates and controls muscle activity.
Genetics is responsible for causing ET in half of all people with the condition. A child born to a parent with ET will have up to a 50% chance of inheriting the responsible gene, but may never actually experience symptoms. Although ET is more common in the elderly -- and symptoms become more pronounced with age -- it is not a part of the natural aging process.
Who Gets Essential Tremor?
Essential tremor is the most common movement disorder, affecting up to 10 million people in the U.S.
While ET can occur at any age, it most often strikes for the first time during adolescence or in middle age (between ages 40 and 50).
What Are the Symptoms of Essential Tremor?
The primary symptoms associated with essential tremor include:
- Uncontrollable shaking that occurs for brief periods of time
- Shaking voice
- Nodding head
- Tremors that worsen during periods of emotional stress
- Tremors that get worse with purposeful movement
- Tremors that lessen with rest
- Balance problems (in rare cases)
The uncontrollable shaking associated with ET is not unique to this condition. Many different factors or diseases can also cause tremors, including Parkinson's disease, multiple sclerosis, fatigue after exercise, extreme emotional distress, brain tumors, some prescription drugs, metabolic abnormalities, and alcohol or drug withdrawal.
Can Essential Tremor Increase the Risk for Other Illnesses?
Drugs used to treat essential tremor may also increase a person's risk of becoming depressed.
Most experts believe that there is no increased risk for Parkinson's disease for people with ET. On the other hand, some people diagnosed as having ET are initially incorrectly diagnosed and subsequently turn out to have Parkinson's disease.
How Is Essential Tremor Diagnosed?
A doctor can usually diagnose essential tremor based on reported symptoms and a complete neurological exam. There is no specific blood, urine, or other test used to diagnose ET.
How Is Essential Tremor Treated?
Mild essential tremor may not require treatment. However, if ET interferes with your ability to function or if you find it socially unacceptable, there are treatments that may improve symptoms. Treatments may include medications or surgery.
- Medications: Oral drugs can significantly reduce the severity of essential tremor. Medications include Inderal, Mysoline, Neurontin,and Topamax Other drug options include the tranquilizers Ativan, Klonopin, Valium, and Xanax. Botox injections may also be a treatment option. This treatment has been effective for vocal and head tremors.
- Surgery: Deep brain stimulation (DBS) is a surgical treatment option for people with severe tremor despite medical therapy. DBS involves surgical implantation of electrical leads into the thalamus. This is an area deep within the brain that coordinates muscle control that is thought to be affected in ET.
- Focused Ultrasound: ExABlate Neuro uses magnetic resonance images (MRI) to focus ultrasound to destroy tissue in the thalamus. Patients are awake and responsive during the entire treatment.
Can Essential Tremor Be Prevented?
Because we do not know the exact cause of essential tremor, there is currently no way to prevent it. However, knowing that ET has a genetic link brings us further in the search for effective treatments and, ultimately, ways to prevent it.
Can Essential Tremor Be Cured?
There is no cure for essential tremor, but treatments that provide relief from its symptoms may be helpful in improving quality of life. These include drugs and surgery that ease tremor. But not every treatment or procedure is effective for every person with ET. Your doctor will recommend an individualized treatment plan, including certain lifestyle changes that may help to reduce your tremors.