What are the other Names for this Condition? (Also known as/Synonyms)

• Benign Essential Tremor (no longer used)
• ET (Essential Tremor)
• Familial Tremor

What is Essential Tremor? (Definition/Background Information)

• Essential Tremor (ET) is a progressive condition, characterized by involuntary and rhythmic shaking of different parts of the body. This condition is different from the tremors caused by other medical illnesses, such as Parkinson’s disease, or those that result from a head trauma
• The likelihood of being affected with Essential Tremor increases with age, and it is more common in individuals older than 65 years of age. A family history of the disorder is a major risk factor for being diagnosed with this condition
• The exact cause of Essential Tremor is unclear, although a genetic basis is suspected. It is researched that certain genes may be involved in the development of this condition. Some cases are believed to be inherited in an autosomal dominant manner. In individuals with Essential Tremor, stress, caffeine use, emotional upheaval, drop in blood sugar, and fatigue can exacerbate the condition
• The main symptom of ET includes tremors in the hands and feet, which can progress to other body parts, particularly to the head. The shaking can be quick or prolonged, may occur internally or externally, and may be felt when the individual is mobile and active or while resting
• Since Essential Tremor is a progressive condition, it can lead to complications such as inability to perform routine daily functions. ET can also cause abnormal gait and problems with movement coordination. There is evidence to suggest that individuals with ET have an increased risk for developing Parkinson’s disease as well
• The treatment options for Essential Tremor include medication and surgery for advanced cases. Non-medical approaches, such as relaxation therapies and “weighting” may also be recommended with other treatment options
• Presently, there are no known methods of preventing this disorder. Relaxing and coping with stress effectively may help in avoiding the progression of one’s symptoms
• Essential Tremor is considered a benign condition. However, the worsening of symptoms may affect the quality of one’s life; it can also cause severe psychological stress

Who gets Essential Tremor? (Age and Sex Distribution)

• Essential Tremor is reported to occur worldwide, with an estimated frequency of 23:100,000 
• Approximately, 4% of the individuals over the age of 40 experience some type of tremors. Generally, individuals over the age of 65 years are most likely to be affected
• Both genders of all ages can be affected by this condition
• All racial and ethnic groups may be prone to Essential Tremor

What are the Risk Factors for Essential Tremor? (Predisposing Factors)

The risk factors for Essential Tremor may include:

• A family history of the disorder
• Advancing age; with elderly individuals being more prone to the condition

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Essential Tremor? (Etiology)

The exact cause of Essential Tremor is not known. However, it is believed that there is a genetic basis to the condition.

• Some evidence exists, on the contribution of genes on the long arm of chromosome 3 and short arm of chromosomes 2 and 6, to the disorder
• It is believed that these genes, when mutated, may result in the development of ET, in combination with certain other environmental triggers
• In post-mortem studies, loss of Purkinje cells in the cerebellum of the affected individuals has been reported. Also, such studies have reported the presence of Lewy bodies (aggregates of protein inside nerve cells common in Parkinson’s disease and dementia) in individuals with Essential Tremor
• When the condition runs in the family, it is inherited in an autosomal dominant pattern. In this type of inheritance, a single defective gene inherited from an affected parent in every cell of an individual’s body, is sufficient to cause the disorder

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring.

What are the Signs and Symptoms of Essential Tremor?

The signs and symptoms of Essential Tremor may vary in type and severity among individuals, and even among affected members of the same family.

The common symptoms of ET include:

• Tremor in the extremities, particularly the hands and feet; the tremors can:
  • Be intense or mild
  • Be fleeting or protracted
  • Be felt internally with no signs of it on the outside, or it can be visible externally
  • Occur when an individual is executing a voluntary movement, or when he/she is resting
  • Occur when an individual is holding something steady, such as a newspaper or book
• Tremors in the head and other parts of the body
• Tremors in the vocal cords

These tremors can worsen with the following:

• Caffeine use
• Emotional upheaval
• Being tired
• Fever
• Drop in blood sugar
• Stress

How is Essential Tremor Diagnosed?

Essential Tremor is diagnosed through the following measures:

• A complete physical examination and assessment of symptoms
• A thorough evaluation of family medical history
• Neurological examinations to rule out other possible causes, such as Parkinson’s disease

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Essential Tremor?

Essential Tremor can lead to the following complications:

• Speech impairment, owing to tremors in the voice box
• Inability to accomplish simple and daily tasks, such as holding something or tying shoes
• Effect on coordinated muscle movement (ataxia)
• Abnormal gait
• Social anxiety, embarrassment, and depression
• Increased risk for Parkinson’s disease

How is Essential Tremor Treated?

The following are the treatment options for individuals with Essential Tremor. The treatments are based on severity of symptoms and can be modified based on the individual’s response:

• Relaxation therapies
• “Weighting” therapy, wherein weights are applied to an individual’s limbs to offer relief from symptoms
• Beta-blockers, such as propranolol, atenolol and sotalol
• Anti-seizure medicines such as primidone, topiramate, gabapentin, and benzodiazapene alprazolam
• Anti-depressants
• Botulinum toxin injections
• Surgery, in advanced cases, which may include:
  • Placing a “surgical lesion” in an area of brain known as the ‘ventral intermediate thalamus’
  • Deep brain stimulation

How can Essential Tremor be Prevented?

At the present time, there are no methods or guidelines available for the prevention of Essential Tremor.

• If there exists a family history of the condition, getting educated on ET may help an individual identify the symptoms and seek medical help
• Practicing relaxation techniques to reduce stress, reducing caffeine intake, maintaining good glycemic index, and taking adequate rest may help delay progression of the signs and symptoms of the disorder
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders such ET

Regular medical screening at periodic intervals with tests, and physical examinations are highly recommended.

What is the Prognosis of Essential Tremor? (Outcomes/Resolutions)

• The prognosis of Essential Tremor is good, if the condition is diagnosed early and treated promptly
• However, ET is a progressive movement disorder, and therefore, involuntary shaking can interfere with an individual’s ability to perform simple tasks. This may lead to severe anxiety and depression

Additional and Relevant Useful Information for Essential Tremor:

In the USA, about 10 million individuals are reported to have Essential Tremor.