Tremor

What is tremor?

A tremor is an involuntary, rhythmic muscle movement. These movements are often back-and-forth actions of one or more body parts.

Most tremors affect the hands. However, tremors can occur in the arms, head, face, vocal cords, trunk and legs.

Children with tremor often have back-and-forth, or oscillating body movements. They may also have a shaky voice. Tremors can affect fine motor coordination, such as writing and gripping objects. Tremors become more severe and may be triggered when your child is feeling stress, fatigue, or strong emotion.

Different types of tremors

Tremors have different names depending on when they occur, such as:

• resting tremor, which occurs at rest
• postural tremor, which occurs when a person assumes a specific posture
• intention tremor or action tremor, which gets worse during an intentional movement

Tremors are also described based on how they are caused. This includes how severe the movements are and what parts of the body are affected. Some common types are listed here.

Essential tremor

This is the most common type of tremor. It starts on one side of the body. Sometimes, it is progressive. This means that the other side of the body becomes affected too. It mostly affects the hands. The head, voice, tongue, legs and trunk can also be involved.

Physiological tremor

This is a mild form of tremor without an underlying cause. Physiological tremor can affect all voluntary muscle groups. It is made worse by fatigue, low blood glucose levels, metal poisoning, stimulants, alcohol withdrawal and heightened emotion. This is a fast tremor, and is not usually bothersome to the child.

Dystonic tremor

The dystonic tremor is triggered when the child is in a certain posture or moves a certain way. Rest and touching the affected muscle may help to relieve the tremor.

Cerebellar tremor

This is a slow tremor that occurs during movements that have a purpose, like pressing a button. It is caused by brain damage in the cerebellum. Common causes of cerebellar damage in children include multiple sclerosis, stroke and tumours. The tremor is triggered on the same side of the body as the brain damage.

Parkinson's tremor

This type of tremor is also called "pill-rolling." The tips of the thumb and index finger come together and then apart in a circular movement. Parkinson's tremor can also affect the chin, legs and trunk. It is an early sign of Parkinson's disease, which most often occurs after the age of 60. It is rarely seen in children, but Parkinson's tremor can also occur as a result of brain damage.

Signs and symptoms

Signs and symptoms of tremor may include:

• a rhythmic shaking in the arms, hands, neck or voice
• difficulty writing or drawing. Most difficulties will be seen with fine motor skills

Symptoms of tremor can worsen with anxiety, stress and caffeine.

Tremors are caused by conditions that affect the brain

A tremor may be a symptom of other neurological conditions. This is because certain areas of the brain control movement. Conditions that affect brain function include stroke, traumatic brain injury and neurodegenerative diseases. Tremor can also be inherited. Alcohol abuse, poisoning and certain medicines can also cause tremor because of their effect on the brain.

Diagnosis of tremor

Tremor is diagnosed by clinical history and observation

Your doctor may make the diagnosis by looking at what kind of tremor you or your child has, where the tremor is located, the characteristics of the tremor (frequency and amplitude), its triggers, and the factors that worsen or improve the tremor.

It is important to remember that tremor by itself is just a symptom and there are several causes for tremor. Depending on what your doctor observes, they may request other tests such as an MRI, an EMG (an electromyography test shows how the muscles work), blood work or genetic testing to determine the exact cause.

Treating tremor

Tremors cannot be fully cured. Often, a tremor can be made less severe through treatment with drugs. The type of drug used depends on the type of tremor. Other measures that may help to reduce tremor include staying away from things that trigger a tremor, such as caffeine.

With more severe tremor, surgery may be an option. However, surgery for tremor is rare in children.

Potential complications of tremor

Tremor is not considered a life-threatening condition. However, the prognosis will depend on the underlying condition causing tremor. For some people, the movements can be disabling.

Resources

National Tremor Foundation (UK)