Essential Tremor

Essential tremor is a neurological condition causing involuntary shaking or jerking. The hands and arms are the body parts most often affected by essential tremor, but the movements can sometimes involve the rest of the body and its functions, particularly the head and the voice. 1 2In some cases, these symptoms can be mild and do not require any treatment. However, a person badly affected by tremors can find everyday tasks difficult to complete.

The exact cause of essential tremor is unknown. However, most evidence suggests that there is a genetic link. People with essential tremor usually have a family member that also has the condition. 3

Essential tremor is among the most common movement disorders, with around one in 50 Americans thought to be living with the condition. 4 The majority of those affected are over 40, but symptoms can begin at a younger age. 3 1

Essential tremor can sometimes be confused with other conditions that cause tremor such as Parkinson’s disease and dystonia.

Treatment for essential tremor is aimed at managing the symptoms through medication, therapy and lifestyle management, rather than trying to cure the condition. Tremors tend to get worse over time, but most people affected experience a lessening of their symptoms after treatment. In more severe cases, doctors may suggest surgical intervention, targeting the thalamus within the brain.

The most common symptoms of essential tremor are fast, shaky movements in the hands and arms. The two main types of tremor experienced by people with essential tremor are: 5 6

• Postural tremor, which occurs when holding the body in any kind of posture against the weight of gravity, such as holding the arms upright
• Kinetic tremor, which occurs when completing any voluntary movement, such as drinking a glass of water or tying shoelaces

In some cases, essential tremor can also occur when the affected person is at rest, e.g., sitting or lying down. The movements can affect both sides of the body, but are usually noticed more often in the dominant hand, as it gets worse when doing intentional movements, such as reaching for a glass or grabbing a pencil. 1

Essential tremor can also affect other body parts. The areas most commonly affected besides the hands and arms are: 6 1

• The head, which moves in a nodding yes or shaking no movement
• The voice, which shakes or quivers during speaking
• The jaw, which clenches or bites repeatedly

Other parts of the upper body and the legs are sometimes affected by essential tremor, although this is rare. 1

If you are experiencing tremor-like symptoms, then try a symptom assessment on the Ada app.

In mild cases, symptoms can cause little to no disruption to daily life. However, in more severe cases, the shaking can stop people from completing everyday tasks and may cause embarrassment or stress.

Studies have shown that people with essential tremor are more likely to experience depressive episodes and anxiety. 7 Treatments for these mental health conditions include talking therapy and medication.

Essential tremor can often be confused with Parkinson’s disease, which also causes tremors. This is partly because there are no laboratory tests as yet to confirm a diagnosis of either of these conditions easily. Doctors generally rely on using physical examinations and questions about medical history to decide which condition the affected person has.

While tremor is the main symptom of essential tremor, those with Parkinson’s disease also experience the following: 8 9

• Slowness of movement, or even “freezing” when wanting to start a movement
• Rigid muscles

People with Parkinson’s disease are more likely to experience tremor symptoms while they are at rest. The tremor in Parkinson’s disease tends less often to be an action tremor, i.e., one that occurs during intentional movements, such as grabbing a glass or using cutlery.

There are also a number of other differences between the tremors caused by Parkinson’s and those experienced by people with essential tremor: 6 10 9

• Tremors caused by Parkinson’s disease are usually slower
• Alcohol can reduce the symptoms of essential tremor, but has no effect on a tremor caused by Parkinson’s disease
• Tremor in the head is more frequently observed in essential tremor than in Parkinson’s disease
• A period of a few seconds or even minutes between a person holding their body against gravity and the tremor beginning may be more common in Parkinson’s disease. This pause between a posture that triggers tremor and the tremor beginning is less likely to be seen in people with essential tremor

Several tests can be used to help a doctor in attempts to distinguish between the two conditions, including ones that look at the power and the frequency of a tremor in action.

A person can be affected by both essential tremor and Parkinson’s disease at the same time.

Read more about Parkinson’s disease »

The exact cause of essential tremor is unknown, but research has suggested that it may be due to some sort of minor brain dysfunction.

The majority of people affected have a close relative that also has the condition. If a parent has essential tremor, then there is thought to be a 50% chance that their child will develop the condition at some point in its life. 11

The symptoms of essential tremor are likelier to appear as the affected person gets older. Most people with the condition are not diagnosed until they reach their 40s. 3 1 However, essential tremor has been observed in people of all ages, including children.

It is thought that several factors can make a tremor worse. They include: 11 12

• Caffeine, e.g. through coffee or energy drinks
• Other stimulants
• Anxiety and stress, as well as mental exhaustion
• Tiredness and physical exhaustion
• Low blood sugar

Essential tremor is usually diagnosed after a medical exam, which includes the affected person explaining their symptoms to a medical professional. A doctor may ask for certain tasks to be completed, or certain body movements to be made, so the tremor can be seen in action.

As the cause for essential tremor remains unknown, there is no test to diagnose it for certain. However, a medical professional may still recommend tests to rule out other causes for the tremor, e.g. multiple sclerosis or head trauma. These tests can include: 3 12

• Blood tests
• Magnetic resonance imaging scans
• X-rays

There is no cure for essential tremor, but several treatment options exist that can minimize the symptoms. 3

In mild cases, where there is little to no disruption to daily life and activities, the person affected may need no treatment at all. When a person’s quality of life begins to be diminished by essential tremor, the first course of action will usually be medication.

There are two types of medication generally used to minimize tremor: 3 11

Beta-blockers: These work by blocking the hormones adrenaline/epinephrine and noradrenaline/norepinephrine from reaching their target sites within the body and thereby also hindering these hormones’ regular effects on the body, e.g. this slows down the speed of the heart beat. The most commonly used beta-blocker for essential tremor is propranolol, which lessens the symptoms of over half of people with the condition.

Anti-seizure medications: When beta-blockers do not work or are not tolerated, anti-seizure medication such as primidone, which is usually used to treat epilepsy, may be prescribed.

Both of these types of medication have some side effects, which a physician will advise upon before use. Beta-blockers and anti-seizure medication usually do not improve vocal tremor. 13 14

Injecting botulinum toxin, which is commonly known as botox, is an effective treatment for tremor in the head, neck and voice. 13 It can also be used for tremor in other parts of the body, but the muscle weakness it causes may outweigh the benefits.

When medication is not effective in treating a person’s tremors, surgical intervention may be recommended. All types of surgery for essential tremor currently involve the thalamus, which is located deep within the brain. The thalamus is crucial for communication between the brain and the rest of the body. The three main thalamic interventions are: 2 3

For this type of intervention, long thin wires with electrodes on the tips are implanted into one or both sides of the thalamus during surgery. These wires are hooked up to a battery-operated electrical device known as a neurostimulator, which is implanted underneath the skin of the chest, near to the collarbone. The neurostimulator can be turned on and off by a magnet. Electrical signals are sent from the neurostimulator to the thalamus. In many cases, this seems to reduce the severity of tremors. 15 ref1

The advantage of choosing deep brain stimulation as an intervention is that no lasting damage is caused to brain tissue, which can sometimes occur during a thalamotomy. 1

During a thalamotomy, a small part of the thalamus is very precisely targeted and removed. A technique known as focused ultrasound has relatively recently emerged as a non-invasive method of performing a thalamotomy using soundwaves. 16

A person undergoing a focused ultrasound thalamotomy will have their head shaved and have their head placed in a frame. A silicone cap is placed on the skull and linked up to the device that produces the sound waves and is known as an ultrasonic transducer. The transducer is filled with chilled, degassed water that can be delivered into the cap between the soundwaves to prevent the skull overheating. The person undergoing the procedure is then placed into a Magnetic Resonance Imaging scanner, which allows the doctor to very precisely guide the ultrasound waves towards the part of the thalamus that needs to be targeted. 17

A thalamotomy is usually only performed on one side of the brain. This means that it will only usually improve tremor in the right or left half of the body. If both sides of the brain are targeted, there is a considerable risk of a person’s ability to speak being affected, as well as some other potential side effects.

A conventional thalamotomy also removes a small part of the thalamus. During a conventional thalamotomy, a burr hole is drilled into the skull, through which a probe is guided into the thalamus. A doctor will then use radiofrequency to target the relevant part of the thalamus. 18

Conventional thalamotomy is a rarely performed procedure in the western hemisphere. The necessity for permanently removing part of the thalamus means, that deep brain stimulation is generally preferred by doctors. 15

Good to know: Thalamotomy and deep brain stimulation may potentially have some serious, adverse side-effects, which a clinician will go over before treatment, so the person involved can make an informed decision weighing in the benefits as well the risks of these treatment options.

Exercise or physical therapy can help build muscle strength and improve muscle control, which can give people with essential tremor more control over their body. A physical therapist can recommend which activities are beneficial and safe, depending on the severity of the person’s symptoms and also their daily activities and needs.

Speech therapy can sometimes be helpful and is therefore recommended for people affected by vocal tremor. 13

Occupational therapy can assist a person in adapting to lifestyle changes caused by tremor. For example, an occupational therapist treating essential tremor may recommend the use of weighted utensils and plates for eating. 7

People with essential tremor may be advised to cut food and drink containing caffeine out of their diet. This includes: 1 19

• Coffee
• Energy drinks and some sodas
• Dark chocolate
• Coffee-flavoured ice creams

Some over-the-counter medications, particularly painkillers, may also contain caffeine. To find out if a medication contains caffeine, check the label before use, or in case of doubt, ask your pharmacist or doctor.

The symptoms of essential tremor may lead a person to eat less, because of the added difficulty of both cooking and using cutlery. An occupational therapist should be able to advise on special implements such as weighted cutlery, as well as cooking methods adapted to a person with the condition’s needs.

There are no scientific studies that support the use of natural or herbal remedies in reducing essential tremor. However, treatments that can induce relaxation, such as massage or aromatherapy, may be useful in reducing stress, which is a contributing factor for tremor that can make it specifically worse in many cases. Consult with a doctor before trying any alternative therapies, and don’t discontinue any previously prescribed treatment, without first checking in with your doctor. 20 21

Most people with essential tremor find that drinking alcohol can lessen any shaking symptoms while they are occuring. 1 3 This is also one way of distinguishing essential tremor from Parkinson’s disease, as tremors caused by the latter condition do not respond to alcohol.

However, tremors may worsen after the effects of the alcohol wear off. 1 There is also the danger of becoming dependent on alcohol, which can cause many negative health and undesirable social effects.

• senile tremor
• benign essential tremor
• familial essential tremor

Q: Essential tremor vs. intention tremor: what is the difference?
A: While essential tremor is a condition, intention tremor is a type of tremor, specifically a type of kinetic action tremor, that may be experienced by a person affected by essential tremor. Intention tremor describes a tremor felt as a person completes an action directed towards a target, such as putting a key into a lock. The tremor usually intensifies the closer the person gets to the target. 1