“Intention tremor” refers to a person making an intended body movement. This is not a symptom of Parkinson’s disease, so it cannot be said that it is common in the condition. However, people with Parkinson’s disease commonly experience resting tremors.

Intention tremors are a specific type of tremor. Tremors are the most common movement disorder.

Some tremors can occur simultaneously with breaks in between, while others can be constant. Tremors may also occur sporadically on their own or as the result of another disorder.

In this article, we outline what intention tremors are and discuss whether they are common in people with Parkinson’s disease. We also outline the causes and diagnosis of intention tremors.

A person's hand shaking. Intention tremors can cause a person's limbs to shake.Share on Pinterest
Elizabeth Fernandez/Getty Images

Tremors are involuntary, rhythmic muscle contractions that cause one or more parts of a person’s body to shake.

Intention tremors occur when a person makes an intended movement toward a target, such as lifting a finger to touch the nose.

The intention tremor often worsens as the individual gets closer to the target.

People with Parkinson’s disease do not commonly experience intention tremors. They often experience resting tremors. Resting tremors are usually the first motor symptom of Parkinson’s disease to appear.

Resting tremors occur when a person is relaxed. For example, their hands may shake while they sit.

However, resting tremors can often become less pronounced or go away entirely when a person carries out actions. For example, their tremor may become less pronounced when they reach out their hand to shake hands with someone.

The most common cause of intention tremors is multiple sclerosis (MS).

However, there are several other possible causes of these tremors, including:

  • Psychological causes: These may include anxiety, anger, fatigue, and fear.
  • Essential tremor: This is another type of tremor that often causes intention tremors. Up to 38.5% of people with essential tremors also have intention tremors.
  • Certain medications: Medications that may cause intention tremors include anti-epileptic medications, such as phenytoin and carbamazepine.
  • Cerebellar infarct: This is another name for a cerebellar stroke. It occurs when there is an interruption to the blood supply to a portion of the area of the brain called the cerebellum. Intention tremors are one possible symptom of cerebellar stroke.
  • Trauma: Traumatic brain injuries can lead a person to develop intention tremors.
  • Hepatocerebral degeneration: This is a rare neurological symptom of chronic liver disease. This can cause several symptoms, including intention tremors.
  • Toxic causes: These include a barbiturate overdose, alcohol dependence, and mercury poisoning.
  • Wilson’s disease: This is a rare inherited disorder that causes copper to accumulate in a person’s liver, brain, and eyes.

A healthcare professional will usually diagnose a person’s tremor based on a physical and neurological examination and a person’s medical history. They may also use certain tests.

Examinations

During the physical exam, a healthcare professional may assess:

  • whether the tremor occurs when the muscles are at rest or in action
  • where on the body the tremor occurs
  • if the tremor occurs on both sides of the body
  • the frequency and amplitude of the tremor

They may perform a neurological exam to check for other findings, such as:

Tests

When diagnosing tremors, a healthcare professional may use blood or urine tests to help rule out certain metabolic causes and medications as the cause of the tremor.

These tests may also help them to identify any contributing causes, which may include drug interactions or alcohol use disorder.

A healthcare professional may also carry out imaging tests to help determine if a person’s tremor is the result of damage to the brain.

Additional tests can help determine the person’s functional limitations. These can include asking a person to perform tasks, including drawing a spiral or placing their finger on the tip of their nose.

An electromyogram can measure a person’s involuntary muscle activity. It also measures muscle response to nerve stimulation. This test can help diagnose muscular or nerve issues.

Resting tremors and intention tremors occur at two distinctly different times.

Intention tremors occur when a person makes a direct and purposeful body movement. Resting tremors occur when a person is relaxed.

People with Parkinson’s disease do not usually experience intention tremors. However, they do commonly experience resting tremors.

Some medical professionals may refer to resting tremors as “pill-rolling” tremors. This is because these tremors often cause a person to make circular finger and hand movements that resemble the rolling of small objects or pills in their hand.

Common causes of resting tremors include:

  • Parkinson’s disease: Parkinson’s disease is the most common cause of resting tremors.
  • Other Parkinsonian syndromes: These syndromes include multisystem atrophy, progressive supranuclear palsy, and corticobasal degeneration.
  • Medications with dopamine receptor-blocking properties: Some of these medications can cause a person to develop resting tremors. These medications include antipsychotic and antiemetics, such as metoclopramide, and antivertigo medications, such as meclizine.
  • Other medications: Some medications without dopamine receptor-blocking properties can also cause resting tremors. These medications include valproate, calcium channel blockers, selective serotonin reuptake inhibitors (SSRIs), lithium, tetrabenazine, and amiodarone.

Learn more about Parkinson’s tremors and how they differ from other tremors.

Possible treatment options for tremors include:

  • Medications: These include beta-blockers, antiseizure medications, sedatives, Parkinson’s disease medications, and botulinum toxin.
  • Focused ultrasound: This involves using focused ultrasound technology to create lesions in tiny areas of the brain’s thalamus. This treatment is only for people with essential tremors who do not respond well to medications.
  • Surgery: A healthcare professional may recommend surgery if a person does not respond well to medications or has a severe tremor that significantly impacts their daily life.
  • Lifestyle changes: Certain lifestyle changes may help a person manage their tremor symptoms. These can include seeing a physical therapist, speech therapist, or occupational therapist, and avoiding or reducing the intake of tremor-inducing substances, such as caffeine and certain medications.

If a person is experiencing symptoms of tremors, experts recommend they contact a healthcare professional immediately.

There is no cure for most tremors. However, there are treatment options to help a person manage the symptoms. It is also important that healthcare professionals find the underlying cause of the tremor, to rule out serious conditions.

Tremors are involuntary, rhythmic muscle contractions. They cause one or more parts of the body to shake.

Intention tremors occur when a person makes an intended movement toward a target.

People with Parkinson’s disease rarely experience intention tremors. Resting tremors are a common symptom of Parkinson’s disease.

Possible causes of intention tremors include MS, brain injury, and certain medications.