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Essential Tremor vs. Intention Tremor

Medical Reviewer: Dhira Khosla, D.O.

No matter where you find them—in your hands, head, or legs—noticing tremors can trigger a worrying response and bring up a lot of questions. These involuntary movements can range from an intermittent inconvenience to making daily tasks nearly impossible.

Tremor can occur for a variety of reasons, ranging in severity. In this post, we’ll discuss two possible causes of tremor symptoms: essential tremor and intention tremor. We’ll start with an explanation of both, then take a look at essential tremor vs. intention tremor by detailing their differences in cause, diagnosis, and treatment.

Contents

What is Intention Tremor?

Intention tremor is defined as a series of rhythmic, involuntary movements, typically occurring while an individual is completing a purposeful and voluntary movement, like reaching for a glass from a kitchen cabinet. This can look like a slow, zig-zag type of gesture. Intention tremor often intensifies as the individual proceeds to reach for a glass, bring a utensil to their mouth, or complete some other voluntary movement. This type of tremor is also categorized as an action tremor, or kinetic tremor, which occurs during physical gestures. Intention tremor, as well as other types of kinetic tremor, most often affect the limbs, usually the upper limbs, and in some cases, the speech muscles.

Intention tremor causes

Intention tremor may be caused by the following:

  • Multiple sclerosis (MS): A disease where the immune system attacks the protective layer (myelin) that covers the nerves. As the disease progresses, communication between the brain and body declines. Tremor is one side effect that can occur as the brain and body start to lose their connection.
  • Cerebellar dysfunction/lesions: Damage to the cerebellum can cause intention tremor, among other symptoms, such as, ataxic gait, difficulty completing daily tasks, dysmetria, and hypotonia.
  • Wilson’s disease: A rare genetic disorder in which copper builds up in the liver, brain, and other vital organs. Involuntary movements as well as muscle stiffness may occur as a result of Wilson’s disease.
  • Metabolic conditions: Hepatocerebral degeneration, among other metabolic conditions, can occur in individuals with liver damage. Intentional tremor is one symptom that may be related to these conditions.
  • Psychological conditions: Psychological conditions such as anxiety can also cause shaky hands and limbs.
  • Medications: Intention tremor may also occur as a result of certain medications, including, cancer medicines, seizure medicines, mood stabilizers, asthma medication, antidepressants, and heart medicines.
  • Exposure to toxic substances: Excessive alcohol use and mercury poisoning can also contribute to intention tremor symptoms.

Intention tremor diagnosis

Intention tremor may be diagnosed based on medical history review, neurological exam, and a combination of physical coordination tests. The two tests typically used for intention tremor diagnosis are the heel-to-shin test and the finger-to-nose test.

  • Heel-to-shin: During this test, the individual will be asked to glide their heel down the opposite leg while lying down. Difficulty to perform this test may indicate coordination problems, and in some cases, intentional tremor.
  • Finger-to-nose: This test looks at an individual’s ability to move their finger from their nose to straight in front of them. Similar to the heel-to-shin test, difficulty to perform this task may signify intention tremor.

Intention tremor treatment

Intention tremor treatment typically involves finding the root cause of the tremor, whether that’s a certain medication, exposure to toxins, or a disease such as MS or Wilson’s. The next steps of treatment may vary depending on the underlying issue at hand.

In addition to identifying the source of intention tremor, a physician may recommend the following treatment methods:

Now that you have a foundational understanding of intention tremor, let’s see how it compares to essential tremor.

What is Essential Tremor?

Essential tremor (ET) is categorized as a movement disorder in which an individual experiences involuntary, rhythmic shaking. Unlike intention tremor, which is more of a slow, zig-zagging motion, essential tremor may look like a faster, oscillating movement. ET is not considered a life-threatening condition itself, however, it causes symptoms that can negatively impact quality of life.

The most prominent symptom of essential tremor is involuntary shaking, which primarily affects the hands, arms, legs, head, or torso. As a result of these involuntary movements, individuals dealing with ET may have difficulty performing daily tasks, such as feeding themselves, drinking from a cup, or writing something down. Additionally, essential tremor may affect the voice box, causing the person’s voice to sound shaky when speaking.

Essential tremor causes

The official cause of essential tremor is not known, however, the following factors are believed to contribute to the disorder:

  • Hereditary factors: Because of its ability to transcend through generations, ET is also referred to as “familial tremor”. Individuals who have a parent with a genetic mutation for ET have a 50% chance of developing it themselves. If essential tremor is hereditary, the symptoms may manifest earlier in life.
  • Age: Although essential tremor is more frequent in persons over the age of 40, it can afflict anyone of any age, including children. The progression of this illness is also linked to age—tremor frequency may decrease with age, but intensity of the tremor may increase.
  • Lifestyle factors:
    • Physical and mental stress
    • Fatigue
    • Hunger
    • Extreme temperatures
    • Caffeinated drinks
    • Excessive alcohol intake
    • Cigarettes and tobacco

Essential tremor diagnosis

Essential tremor can be diagnosed through a variety of neurological, lab, and performance tests:

  • Neurological tests: A physician may use a series of neurological assessments to help eliminate other conditions. Neurological examinations may test:
    • Your ability to feel sensations
    • Your deep tendon reflexes
    • Your muscle strength and tone
    • Posture
    • Gait
    • Coordination
  • Laboratory tests: Blood and urine tests may be used to rule out conditions such as thyroid disease, metabolic issues, irregular drug reactions, and chemical imbalances.
  • Performance tests: These assessments will take a closer look at the severity of an individual’s tremor symptoms and may include:
    • Drawing a spiral
    • Drinking from a glass
    • Holding arms outstretched
    • Writing

For more information, refer to our essential tremor diagnosis guide where we explain these tests in greater detail.

Essential tremor treatment

Essential tremor treatment can be broken up into five categories: non-surgical therapy, lifestyle adjustments, medication, physical therapy, and surgery.

  • Non-surgical therapy: Also known as non-invasive treatments, the goal of these therapies is to mitigate symptoms without invasive and physically taxing surgical treatments. Progress in ET treatment has led to groundbreaking technology found in Cala Trio therapy, a device that calibrates to the wearer’s unique tremor. Surface stimulation is applied to the wrist, which is believed to interfere with the brain’s central tremor network, helping to minimize tremor symptoms.
  • Lifestyle adjustments: It is believed that stress, as well as alcohol, tobacco, and caffeine can contribute to ET symptoms. Your doctor may recommend avoiding stressful scenarios and the aforementioned substances to help treat your tremor.
  • Medication: There are several medications used to help address essential tremor symptoms:
    • Beta-blockers
    • Anti-seizure medicine
    • Tranquilizers
    • Botox injections
  • Physical therapy: Physical therapy may also help individuals with ET improve their coordination, muscle strength, and control. Resistance training is usually the emphasis of physical therapy for essential tremor. This type of resistance training is usually done on the upper body to improve strength and coordination.
  • Surgery: Although they are typically reserved as a last-resort, there are several surgical procedures used to treat ET, including:
    • Thalamotomy
    • Focused Ultrasound
    • Gamma Knife Surgery
    • Deep Brain Stimulation

Comparing Intention Tremor vs. Essential Tremor

Now that we’ve detailed the symptoms, causes, diagnosis, and treatment of these two types of tremor, let’s take a side-by-side look at essential tremor vs. intention tremor.

Tremor causes

Intention tremor causes include:

  • Multiple sclerosis (MS)
  • Cerebellar dysfunction/lesions
  • Wilson’s disease
  • Metabolic conditions
  • Psychological conditions
  • Medications
  • Exposure to toxic substances

Essential tremor causes include:

  • Hereditary factors
  • Age
  • Lifestyle factors (i.e. stress, fatigue, hunger, extreme temperatures, caffeine consumption)

Tremor diagnosis

  • Intention tremor diagnosis usually involves a review of medical history, neurological examinations, and a series of physical coordination tests, including the heel-to-toe and finger-to-nose tests.
  • Essential tremor diagnosis may also include a review of medical history, neurological examinations, lab tests, and physical coordination assessments.

Tremor treatment

Intention tremor treatment mostly focuses on identifying an underlying cause, such as a medication response, psychological condition, or disease. From there, treatment may vary based on findings, but may also involve:

  • Physical therapy
  • Gait rehabilitation
  • Wearing wrist weights
  • Using relaxation techniques

Essential tremor treatment typically involves one or more of the following approaches:

  • Non-surgical treatment
  • Lifestyle changes
  • Medication
  • Physical therapy
  • Surgery

Whether you’re dealing with intention tremor or essential tremor, it can be frustrating to manage your symptoms. Use this guide as a starting point and make sure to contact your doctor if your symptoms persist or worsen. For more information on essential tremor or our breakthrough treatment, visit Cala Trio FAQs or our library of essential tremor and health medicine articles.