In this article:

• What is an action tremor?
• Types of action tremor?
• Common causes of action tremor
• Action tremor vs rest tremor
• Symptoms of action tremor
• Diagnosing action tremor
• Treatment options for action tremor
• Advanced targeting using FAT1 imaging
• Frequently asked questions about action tremor
• Action tremor treatment in London

A tremor is a rhythmic, involuntary shaking movement affecting part of the body. Tremors can occur for a variety of reasons, including stress, fatigue, anxiety or excess caffeine intake, but they can also result from neurological conditions such as essential tremor (ET), Parkinson’s disease or dystonia.

An action tremor occurs during voluntary movement or while maintaining a posture against gravity. Unlike a rest tremor, which occurs when muscles are fully relaxed, action tremor becomes more noticeable when a person is using the affected body part.

Action tremor most commonly affects the hands and arms, but it can also involve the head, voice, jaw or legs. For some people, symptoms are mild and intermittent. For others, tremor can significantly affect writing, eating, work, social confidence and many activities of daily living.

Essential tremor is the most common cause of persistent action tremor and is one of the world’s most common movement disorders.

What is an action tremor?

An action tremor occurs when muscles are voluntarily activated. Symptoms may appear:

• During movement
• When holding a posture
• During fine motor tasks
• When approaching a target

Action tremor can vary in severity depending on stress, tiredness, caffeine, anxiety or underlying neurological disease.

Unlike Parkinsonian rest tremor, action tremor is usually most noticeable during activity rather than relaxation.

Types of action tremor

Action tremor includes several subtypes depending on when the tremor occurs.

Postural tremor

Occurs when holding a position against gravity, such as holding the arms outstretched.

Kinetic tremor

Occurs during deliberate voluntary movement, such as eating, writing or using cutlery.

Intention tremor

Worsens as the hand approaches a target, such as reaching for a cup or pressing a button.

Isometric tremor

Occurs during muscle contraction without movement, such as gripping a heavy object.

Task-specific tremor

Occurs during specific tasks such as handwriting, speaking, playing an instrument or sporting activities.

Common causes of action tremor

Essential tremor

Essential tremor is the most common cause of persistent action tremor.

It typically affects both hands and arms and may also involve the head or voice. Symptoms are often more noticeable during tasks such as writing, eating or drinking.

Many people with essential tremor have a family history of the condition, and symptoms often gradually worsen over time.

Parkinson’s disease

Although Parkinsonian tremor is classically considered a rest tremor, many people with Parkinson’s disease also experience action tremor.

Parkinson’s disease is also associated with:

• Slowness of movement
• Muscle stiffness
• Balance difficulties
• Changes in walking pattern
• Non-motor symptoms such as constipation, fatigue and reduced sense of smell

Enhanced physiological tremor

Enhanced physiological tremor is a relatively common form of action tremor which may be worsened by:

• Stress
• Anxiety
• Fatigue
• Caffeine
• Certain medications
• Thyroid problems

Tremor severity is usually mild and temporary.

Holmes tremor

Holmes tremor is typically a tremor present at rest and on action. It produces a very large amplitude, low-frequency tremor of one side of the body.

Possible causes include:

• Multiple sclerosis
• Stroke
• Brain injury
• Neurodegenerative disease
• Infection

Dystonic tremor

Dystonic tremor occurs in people with dystonia, a neurological condition causing abnormal muscle contractions and postures.

The tremor is often irregular or jerky and may improve when the affected body part is touched in a particular way.

Action tremor vs rest tremor

Action tremor and rest tremor are different types of tremor.

Action tremor:

• Occurs during movement or activity
• Is commonly associated with essential tremor
• Worsens during tasks such as writing or eating

Rest tremor:

• Occurs when muscles are relaxed
• Is commonly associated with Parkinson’s disease
• Often begins on one side
• May improve during movement

Because symptoms can overlap, assessment by a neurologist specialising in movement disorders is important for accurate diagnosis.

Symptoms of action tremor

Symptoms vary depending on the underlying cause but may include:

• Tremor in the hands or arms
• Shaking during movement or activity
• Difficulty writing or using utensils
• Head tremor or voice tremor
• Tremor worsened by stress or fatigue
• Problems with fine motor control
• Symptoms affecting both sides of the body

For some people, symptoms remain mild for many years. For others, tremor may gradually progress and interfere with daily life.

Diagnosing action tremor

Diagnosis usually begins with a detailed medical history and neurological examination.

A neurologist will assess:

• Whether the tremor occurs during rest or movement
• Tremor severity and frequency
• Which body parts are affected
• Associated neurological symptoms
• Family history
• The effect on daily activities

Clinic-based assessments such as handwriting analysis or spiral drawing tests may help evaluate tremor severity.

Depending on the clinical presentation, additional investigations may occasionally be used to exclude other causes. These can include:

• Blood tests
• MRI scans
• CT scans
• Electromyography (EMG)
• Specialist imaging such as SPECT or DaTscan imaging
• Genetic tests

Treatment options for action tremor

Treatment depends on the underlying cause of the tremor, symptom severity and how significantly symptoms affect daily life.

Medication

Medication is often the first-line treatment for action tremor.

Common medications may include:

• Propranolol
• Primidone
• Levodopa in Parkinson’s disease
• Anticholinergic medications in selected cases

Some patients may also benefit from botulinum toxin (Botox) injections, particularly for head tremor, voice tremor or selected limb tremors.

However, medication is not always effective, and some patients experience side effects such as fatigue, dizziness or nausea.

Advanced tremor treatments

For selected patients with medication-resistant tremor, advanced procedural treatments may be considered.

Deep brain stimulation (DBS)

Deep brain stimulation is an established treatment for essential tremor, Parkinson’s disease and dystonia.

The procedure involves implanting electrodes into targeted areas of the brain connected to a battery device placed under the skin of the chest. Electrical stimulation helps regulate abnormal brain activity associated with tremor.

One advantage of DBS is that stimulation settings can be adjusted over time as symptoms change.

Radiofrequency ablation (RFA)

Radiofrequency ablation uses heat generated by radio waves to create a small, controlled lesion in a targeted area of the brain involved in tremor pathways.

The procedure can be effective in carefully selected patients, although possible risks include speech, balance or coordination difficulties.

MR-guided focused ultrasound (MRgFUS)

MR-guided focused ultrasound thalamotomy is an incisionless treatment for selected patients with medication-resistant essential tremor or tremor-dominant Parkinson’s disease.

The procedure uses focused ultrasound energy, guided in real time by MRI imaging, to create a precise lesion within the thalamus – a structure involved in tremor circuits.

Patients remain awake throughout treatment so the clinical team can assess tremor improvement during the procedure itself.

Many patients experience significant tremor reduction during or shortly after treatment, although outcomes and potential side effects vary between individuals.

At Queen Square Imaging Centre in London, patients are assessed by a specialist movement disorder and functional neurosurgery team with expertise in advanced tremor therapies including MR-guided focused ultrasound, DBS and lesioning procedures.

As with all procedural treatments, these interventions carry potential risks and side effects which are discussed carefully during specialist assessment.

Advanced targeting with FAT1 imaging

During MR-guided focused ultrasound, the target area for treatment is usually the Ventral Intermediate Nucleus (Vim) of the thalamus.

FAT1 imaging is an advanced MRI-based imaging technique that combines high-resolution anatomical MRI with diffusion tractography to support more individualised treatment targeting in selected patients.

This approach may help improve target visualisation based on each patient’s unique brain anatomy rather than relying solely on standard anatomical coordinates.

Frequently asked questions about action tremor

Action tremor treatment in London

If you develop a persistent tremor or symptoms affecting movement, it is important to seek assessment from a neurologist specialising in movement disorders.

Queen Square Imaging Centre in London offers specialist assessment and advanced treatment options for tremor disorders, including MR-guided focused ultrasound thalamotomy. Our multidisciplinary team works closely with experts in functional neurosurgery and movement disorders to provide personalised treatment recommendations for each patient.

If you would like to discuss your tremor and what treatment options might be available to you, please contact us.

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