What is a tremor?

In medical terminology, tremor is a movement disorder. Patients with tremor develop rhythmic shaking of hand(s), head or neck, speech, or the whole body. In reality, we may all have some amount of tremor. Try an experiment: extend an arm and hand at 90 degrees and put a paper on the hand, see if you can completely stop the paper from moving. This movement may get more prominent if the person is anxious. It may be impossible to stop the paper from moving, because the arm and the hand underneath are in motion. The gravity is trying to pull the arm down, while muscles are keeping it up, both in a constant tug-of-war. Usually our eyes do not perceive the hand in motion, so we do not call it a tremor. We call it a tremor when we are able to see with our eyes or appreciate the movement, without putting any paper.

Why do I have tremor?

There are numerous reasons for tremor, some with a problem with nervous system and some with a problem in other areas of the body. Common reasons for tremor are anxiety, thyroid disease, drugs, alcoholism, stroke, multiple sclerosis, dystonia, and Parkinson disease. A common cause of hand tremor is what is benign essential tremor.

What are different types of tremor?

The technical terms for tremor are not straightforward, frequently imprecise, and sometimes misleading. Without going into detail of the problems with these terms, following are some tremor types:

A: Resting tremor: This tremor appears when the limb or the body part is either at rest or not involved in a voluntary action. This is the typical tremor seen in Parkinson disease. Tremor at rest can also be seen in severe cases of benign essential tremor.

B: Action tremor: This tremor appears when a hand or a limb is in motion for a voluntary action, and seems to disappear when it is not. This is the most common type of tremor. This tremor typically gets worse in anxiety-provoking situations. It can be further divided into many varieties.

C: Postural tremor: This is a tremor that appears when a patient voluntarily assumes a certain posture, for example if a patient extends arms and hands in front at 90 degrees and tries to keep them stationary.

D: Dystonic tremor: This is also a postural tremor but the patient is not trying to assume that posture. The abnormal posture, or dystonia, is the result of uncontrollable contraction of certain muscle group. A good example is Torticollis, when patient’s neck or head keeps on turning to one side resulting in this type tremor.

How is type of a tremor determined?

This is done by clinical observation. There is no test that is employed to diagnose a tremor. Tests are ordered sometimes to find a condition that may cause tremor, e.g., thyroid tests to look for hyperactive thyroid.

What is benign essential tremor (BET)?

This is a common cause of tremor. The words benign and essential here means that it is only a tremor and there is no other underlying disease. The tremor in this condition is action type; it appears when the patient tries to do a voluntary act, like write, or hold a fork or a drink. Tremor gets worse in anxiety-provoking situation. This type of tremor usually has family history. It may appear in young age and slowly worsens. It usually affects hands, usually one side more than other. It may also affect speech. Its real cause is unclear but the cause is likely central, i.e., in the brain with the circuitry that controls movements.

How is benign essential tremor (BET) treated?

Other than tremor, BET is a benign condition. Patients need counseling about their condition and its nature. There is no medicine to completely stop the tremor. At the same time not everyone needs to be treated, especially if tremor is mild. Patients seek consultation to know the reason for the tremor. Some ask for treatment due to its social and physical impact. It can be helped with a medicine called propranolol, which may also help with anxiety. The other useful medicine is primidone. Rarely, some patients do well on clonazepam.

Majority of patients respond well to this type of treatment but not all, or at least not sufficiently. A procedure called Deep Brain Stimulation is another avenue of treatment.

What is Parkinsonian tremor?

Tremor is common in Parkinson disease but not all patients with this disease have tremor. It may affect a hand or arm, or a leg, on one or both sides. It may also affect chin or head. Tremor may worsen in anxiety provoking situation. The classical hand tremor of Parkinson disease is commonly known as “pill rolling” tremor. One may notice it while patient is sitting or walking. It disappears when the hand or arm is engaged in a voluntary motion. Parkinson patients may also have action type of tremor.

What is a mixed tremor?

It is a term used when a patient has both resting Parkinson type tremor and action type of tremor.

What is intention tremor?

This term needs to be discarded, as it is misleading: neither a patient intends to have a tremor, nor the action triggering it is intended for that purpose. It is a kind of action tremor commonly seen in alcoholics. Imagine someone picking an object, extending arm and hand, and handing the object to someone; with this type of tremor, this action becomes embarrassing as hand and arm may shake as they reach the other person.

What is physiological tremor?

Like described above, everyone has some tremor, which we can call physiological tremor. It may worsen with any illness, stress, anxiety, over-exertion, and lack of sleep.

How is head tremor treated?

Head tremor does not respond well to medicines. If it is caused by cervical dystonia, its treatment with Botox can help. Treatment of anxiety may also help.

How is speech tremor treated?

If it is part of benign essential tremor, the treatment is same as above. If it is due to brain injury from alcohol, quitting alcohol and treatment of anxiety can help.

How is hand tremor of dystonia treated?

An example of hand tremor from dystonia is the so-called Writer’s Cramps, when the hand goes into a spasm, resulting in shaking and making it difficult to write. Medicines do not provide much help. Botox treatment of select muscles may provide appropriate relief.

Can physical and psychotherapy help with tremor?

Therapy can help to control or manage anxiety, which makes tremor worse. So indirectly, by controlling anxiety, it can help.

What should I do if I have tremor?

Discuss it with your primary care physician. There may be some medical condition explaining the tremor, such as hyperactive thyroid, or family history of tremor. A consultation with a neurologist may help confirm the diagnosis, especially in atypical cases and if there is no obvious reason for a tremor.

Where may I get more information about tremor?

American Academy of Neurology
www.ninds.nih.gov