Tremors

What is it about ?

Tremors are small, jerky, repeated movements of one or more parts of the body. They are caused by the involuntary contraction of groups of muscles. The two main diseases that are accompanied by tremors are essential tremor and the Parkinson disease.

How to recognize them?

There are two types of tremors: tremors at rest and tremors during muscular exertion (action-related tremors.

Resting tremor

Resting tremor, as the name suggests, occurs at rest, that is, in the absence of voluntary movement. The tremor most often disappears during activity.

These tremors are slow and wide. They can involve the lower jaw and lip, but hardly ever the head. These tremors are made worse by stress or anxiety.

They are often due to a disease of the brain such as Parkinson disease. They can also be caused by certain medicines (for example antipsychotics (neuroleptics) or metoclopramide, a medicine for nausea and vomiting).

Action-related tremor

The action-related tremor, as the name suggests, occurs during an action, that is, during a voluntary muscle contraction. For example, when trying to do something like grabbing an object (intention tremor) or holding a position (postural tremor).

The tremor can affect the fingers, arms and legs, mouth, head, and even the voice. The tremor also increases with stress and anxiety, but also during activities requiring high precision.

There are several types of action-related tremors:

• the physiological tremor, which can occur in anyone in the absence of disease. The possible causes are stress, exertion, fatigue, cold, withdrawal (for example from alcohol), hypoglycemia or the excessive consumption of nicotine or coffee.

• The essential tremors

More rarely,

• The tremors follow changes in metabolism. For example in the diabetes, the’hyperthyroidism, liver failure, too much cortisone in the blood, adrenal tumor, too low potassium level, too low magnesium level, vitamin B12 deficiency. The tremor is mostly visible in the hands and feet.
• The tremors due to cerebellar disease. They can be hereditary, but are also found in alcoholism, multiple sclerosis, the brain tumors and thecerebral infarction. In this case, the tremor is typical, it is an “intention” tremor, which occurs when the person wishes to perform a specific movement (eg writing or having a cup of coffee).
• The toxic tremor are due to poisoning. For example with heavy metals (mercury, lead, arsenic …), organic compounds, methanol (a type of highly toxic alcohol), cyanide. In addition to the tremors, the person also has muscle contractions and involuntary movements.
• Tremors can occur in a number of diseases of the nerves and brain.
• the psychogenic tremor, finally, often occurs both at rest and in motion. If you don’t pay attention to it, it can suddenly stop.

How is the diagnosis made?

a neurological examination is usually needed to distinguish between different types of tremors and their causes. For this, the person can sometimes be referred to a neurologist.

What can the doctor do?

Treatment of course depends on the cause. Often there is no cure, but symptoms can be reduced.

Want to know more?

• Metoclopramide – CBIP – Belgian Center for Pharmacotherapeutic Information
• Antipsychotics – CBIP – Belgian Center for Pharmacotherapeutic Information

Source

Foreign clinical practice guide ‘Tremblements’ (2000), updated on 09.05.2016 and adapted to the Belgian context on 20.04.2019 – ebpracticenet