ICAT: Tremor, Frequently Asked Questions

What is tremor?

Tremor is the common type of movement disorder that is characterized as muscle contractions, that cause rhythmic shacking on one or more parts of the body. It most commonly occurs in the hands but can also be present in the arms, head, voice, legs, and body, thus interfering with handwriting, the activity of daily living or causing social embarrassment. Tremor can occur intermittently, meaning it appears irregularly, at a separate time with breaks in-between or it can be constant. Tremor itself might not be life-threating but it can be disabling making daily task and work difficult.

What causes tremor?

Tremor is mainly caused by an abnormality in the cerebellum and other associated brain regions, which control motor function and movements. The neuronal cells in these brain regions may become too excited, which lead to tremor. Tremor is a symptom associated with a number of neurological disorders, including essential tremor, Parkinson’s disease, dystonia, and ataxia. Each of these neurological disorders will have a unique cause for tremor and also different tremor characteristics.

How is tremor diagnosed?

Tremor can have a variety of causes; a neurologist will perform an examination and observe the timing for tremor occurrence, tremor frequency, tremor amplitude, and other associated neurological symptoms. Depending on imperative information such as a family history of tremor, age of onset, and symptoms other diagnostic tests such as blood tests and brain scans will be ordered to determine the neurological diagnosis associated with tremor.

How is tremor treated?

Tremor treatment can be divided based on tremor characteristics: rest tremor (often associated with Parkinson’s disease) or action tremor (often associated with essential tremor). Rest tremor can be treated with levodopa, whereas action tremor might respond to primidone or propranolol. Botulinum toxin sometimes can be used to dampen the tremor as well. If tremor becomes refractory, surgical options might be implemented, such as deep brain stimulations, gamma knife, or focused ultrasound. However, the available therapy sometimes is still not satisfactory, and individually tailored treatment program is often necessary. Currently, more research is being done to find therapies that will improve the quality of life of individuals living with tremor. There are also devices and technologies that assist with daily tasks and management of tremor.

What is essential tremor?

Essential tremor is a neurological and movement disorder, which presents typically with uncontrollable shaking (tremor) in the hands while performing a task, i.e. action tremor. The hands are mostly involved in essential tremor, but tremor can also occur in the head and voice. Many people with essential tremor report a family history of tremor. Depending on the individual, the development of cognitive impairment and anxiety and depression can occur. Essential tremor is one of the most common neurological disorders, and it is five times more common than Parkinson’s disease.

What is Parkinson’s tremor?

Parkinson’s tremor is classically a “rest tremor.” The tremor is present when the individual is at rest and ceases during movement, but may occur when limbs such as the hands or fingers are held in one position. In addition to tremor, Parkinson’s disease patients also have slowness, stiffness, and balance problems as associated symptoms. Parkinson’s tremor often starts with one side of the body and subsequently spread to the other side. Levodopa treatment might suppress Parkinson’s tremor to a certain degree but not every patient’s tremor responds to treatment.

What is Dystonic tremor? 

Dystonic tremor is a symptom of dystonia, which is when the brain sends out incorrect messages causing excess activity in the muscles which result in abnormal body movement and posture. Sometimes the abnormal body movements could be rhythmic causing it to become a tremor. Dystonic tremor often occurs in the head or hands and can occur during rest, or inaction. This type of tremor presents commonly in young adults or middle-aged individuals but can occur in all ages. In terms of treatment Dystonic tremor might respond to botulinum toxin injections.