Essential tremor is due to abnormal communication between certain areas of the brain, including the cerebellum, thalamus and brain stem.
In the majority of people with ET, the tremor seems to be inherited as an autosomal dominant trait. This means that each child of a parent with ET has approximately a 50% chance of inheriting a gene that causes ET. Researchers have already located two genes that predispose to ET and are currently trying to locate others.
Not everyone who inherits a gene develops symptoms, and some people have ET and do not have a family history of tremor, possibly suggesting other causes.
At this time, there is no genetic test for ET.
ET neither kills nor shortens lifespan. At best ET is a nuisance. At worst ET disables. Most cases of ET fall somewhere in between the two extremes.
Though ET may first appear at any age between childhood and old age, onset is rare before the age of ten. Most commonly onset is after age 40.
ET is found in all races and in all parts of the world. No one group of people is more likely to develop ET. Men and women are affected equally.
No one can predict how much your tremor will worsen with time. The course of ET is variable and may be progressive over many decades.
Doctors who are trained to evaluate tremor can accurately diagnose ET on the basis of the symptoms and a neurological examination. There are no blood, urine or other tests for ET.
Before making a diagnosis of ET, your doctor may want to investigate other possible causes of tremor such as thyroid disease, excessive caffeine ingestion or medication side effects.
During your physical exam, your doctor will be gathering as much information as possible about your tremor. Here are some questions you may be asked:
Tremor due to medications
Because tremor is a feature of so many conditions, ET can be mistaken for something else. Some people have both ET and another disorder that causes tremor. Note that many prescriptions, over-the-counter and illicit drugs, as well as some herbal remedies, can cause or worsen tremor. Tell your doctor about all the medications you are taking.
If you have mild ET, you may not need treatment. There is no evidence that early treatment stops or slows the natural progression of ET symptoms. With adequate knowledge, many people learn ways to live well with ET. If possible, you should be taken off any medications that may be aggravating tremor.
If ET is interfering with your ability to work or perform daily tasks, or you find it socially disabling, you may want to consider available therapies. It is important to have realistic expectations for therapy. At present, there is no cure for ET. For the oral medications, a 50% reduction of tremor severity is considered good. The goals of treatment are to:
- Reduce tremor severity
- Improve ability to function
- Decrease social handicap
Achieving these goals can sometimes take time, so be patient. While almost two thirds of people with ET benefit from medical therapies, your doctor may have to try two or three different medicines before finding the one that works best for you.
The main medications used to treat ET are propranolol (Inderal) and primidone (Mysoline). Both can be quite effective.
Propranolol (Inderal)
Propranolol is in a class of drugs called beta-blockers. Propranolol has been used for many years, primarily for reducing high blood pressure. It is not clear exactly how it works in treating essential tremor. Other beta-blockers may also be used. Features of propranolol include the following.
- You may experience tremor reduction 1-2 hours after taking a single 10-40 mg dose of the short-acting formulation. This effect usually wears off in about 4 hours.
- Propranolol may be prescribed to be taken as needed, or on a daily basis. A once-daily long-acting preparation is available.
- 60% of people with ET are helped by propranolol. It is most effective against hand tremor and may be effective for tremor of the head, voice and tongue.
- Individual response is variable. Complete tremor reduction is rare.
- Side effects are usually mild and are more frequent at higher doses (more than 120 mg/day of propranolol). The main side effects are decreased pulse rate and blood pressure. Less common side effects are fatigue, depression, impotence, nausea, weight gain, rash and diarrhea. If you experience unpleasant side effects, be sure to tell your doctor. Often the dosage or drug can be changed.
- If you have heart failure, diabetes mellitus or asthma, talk to your general medical doctor prior to taking propranolol. Do not abruptly stop this medication without first consulting with your physician.
Primidone (Mysoline) Primidone is an epilepsy medicine that was unexpectedly found to reduce tremor. It is now used widely for tremor reduction. Some features of primidone are:
- Approximately 60% of people with ET are helped by primidone. Benefit usually persists for 24 hours for each dose.
- dizziness, fatigue, drowsiness and flu-like symptoms -- most of which subside after a couple of days. You can reduce the chance of these symptoms by starting with an extremely small dose at bedtime. If you experience more serious side effects, tell your doctor.
- One quarter of the 50 mg tablet (12.5 mg) or small amounts of the pediatric elixir may be appropriate as initial dose. Only branded Mysoline is available as a 50 mg tablet and pediatric suspension.
- Although primidone may have more initial side effects than propranolol, there are few long-term problems, and primidone may be used successfully for many years. Occasional dose adjustments may be needed.
Combination and other therapies
If your tremor is not well controlled by a beta-blocker or by primidone alone, you may experience better results when you take both medicines together. If combination therapy is not helpful, your doctor may then recommend one of the benzodiazepines such as clonazepam (Klonopin), diazepam (Valium), alprazolam (Xanax) or lorazepam (Ativan). The most common side effect is drowsiness. There is a risk of physical dependence and withdrawal. Although no scientific support is available, other drugs may be used.
Botulinum toxin injections
If medications fail, another therapy may be tried that involves injections of Botulinum toxin into muscles. Botulinum toxin injections have been useful in the treatment of some patients with head and voice tremors. The toxin must be placed into target muscles by a trained specialist, and repeat injections may be needed. Transient weakness of the injected muscles is a potential side effect. This treatment can be expensive, so check with your insurance provider regarding coverage.
If treatment with medications is not effective and ET is very disabling or is putting your livelihood at risk, your doctor may suggest a surgical technique, such as thalamotomy or thalamic stimulation (Activa tremor control therapy). Surgical procedures are expensive but may be beneficial.
Thalamotomy
This is a surgical procedure that involves making a small hole (the size of a dried pea) in a part of the brain called the thalamus. A surgery on one side of the brain produces its effect on the opposite side of the body. The surgery destroys the faulty circuit or brain cells that modulate tremor. At the present time, thalamotomy surgery on both sides of the brain is not recommended as there is an unacceptable risk of loss of speech or other problems.
Approximately 80% of patients have experienced improvement in tremor after this procedure. When effective, medications may be reduced or even discontinued. The procedure may be especially beneficial for people with severe hand, arm or leg tremor that does not respond to medication. Approximately 1 in 20 people suffers some complication from surgery, 1 in 100 people suffers stroke or death. You should discuss these issues with your neurologist and neurosurgeon.
Deep Brain Stimulation (DBS)
DBS is an alternative to thalamotomy. It involves implanting an electrode (a fine wire) deep in the center of the brain. The electrode is connected to a stimulation device, similar to a pacemaker, which is placed under the skin below the collarbone. By sending electrical currents through the electrode, you can interrupt communication between tremor cells. Tremor reduction occurs within seconds of activation and can be dramatic. Significant or complete tremor reduction occurred in approximately 80% of people with this procedure. Tremor medications can often be reduced or even stopped.
The main advantages of this procedure are that implantation on both sides of the brain is possible, the device can be adjusted for optimal effect, and it may be removed, which allows you to keep your options open in case new therapies develop. The risks are similar to thalamotomy. While the surgery is expensive, the procedure and device are FDA-approved and are covered by most insurance providers.
Though there is no evidence that so-called "alternative therapies" are helpful for ET, people have tried a variety of treatments. No good scientific studies are available to encourage the use of alternative therapies. Always talk to your doctor before starting any alternative therapies. While some herbs that induce relaxation may be helpful, others, such as a Chinese herb called ma huang, can worsen tremor. Many people have tried acupuncture, hypnosis and massage therapy. People whose tremor worsens with stress or anxiety may find biofeedback helpful. Others have found physical and occupational therapy to be helpful in terms of providing suggestions for using wrist weights, plate guards and other adaptive devices. These devices can provide considerable benefit in activities of daily living.
Tremor severity may fluctuate during pregnancy and after delivery. You should discuss the use of ET medications with your physician before getting pregnant, as some medications put the developing baby at risk.
Adults with ET often notice that consumption of alcohol reduces their tremors for 1-2 hours. While it is true that alcohol can temporarily reduce tremor, it may not be an appropriate form of "treatment." Use of alcohol to reduce tremor should be discussed with your physician.
Become informed about your condition and learn as much as you can about living with ET.
Instead of restricting your life because of what others may think, explain your condition simply and honestly when you meet new people.
If your child has ET, you may want to talk to teachers in person about the neurological basis for symptoms.
Find ways to reduce stress and learn some relaxation techniques.
Avoid things that may worsen tremor, such as caffeine and certain prescription medications.
Contact the IETF for an information packet or information about joining or starting a support group for ET.
Work closely with your doctor to find the most effective treatment. Take an active role in your treatment. Discuss your symptoms and questions with your doctor. The more you know about ET and treatment, the easier it will be to adapt, minimizing the interference with your daily life. It is important to discuss expectations of treatment results, side effects and other issues such as employment.
Consumer Reports Best Buy Drugs is a free public education service from the nonprofit Consumers Union, publisher of Consumer Reports. Go to www.crbestbuydrugs.org to learn more about affordable drug treatment options to discuss with your physician. You'll also learn what you need to know about the effectiveness, safety, and cost of many widely used prescription drugs.
No, medications for Parkinson's disease (PD) do not help ET. Symptoms of PD are caused by changes in dopamine levels in the brain. Serotonin levels are affected in ET.
Although PD may look like ET to an untrained eye, PD tremor, generally, occurs at rest. Tremor due to ET occurs during action. PD also causes progressive slowness, stiffness and loss of balance.
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