Essential tremor is a neurological condition and movement disorder that causes involuntary shaking or trembling of part of the body, such as the hands, head, or jaw.
Essential tremor is the most common movement disorder, and around 10 million people in the United States experience it.
Essential tremor usually occurs alone, without other neurological symptoms, though some people may also have trouble with balance, for example.
In this article, we describe the symptoms, causes, diagnosis, and treatment of essential tremor.
The main symptom of essential tremor is trembling, particularly of the hands. The person cannot control this movement, which tends to have a rhythmic pattern. It may be an up-and-down or side-to-side motion.
- legs and feet, less commonly
Essential tremor does not usually happen at rest. It can happen during activities such as eating and drinking, shaving, applying makeup, or writing. A person may also notice it when they hold out their hands.
The tremor is progressive, which means that it tends to become more severe over time. It can make daily activities, such as drinking from a glass, tying up shoelaces, or writing difficult.
A person with essential tremor may also experience:
Essential tremor is a neurological condition and a movement disorder. Tremors happen when there is faulty signaling between the nerves and the muscles they connect with, but the exact cause remains unclear.
There may be genetic factors involving specific chromosomes or the nervous system, but research has not yet confirmed this. According to the National Organization for Rare Disorders (NORD), 17–50% of essential tremor cases may be hereditary.
The risk of developing essential tremor increases with age, but anyone can have it, including children.
There may be links between essential tremor and:
- the use of some medications
- exposure to toxins such as lead and mercury
- an overactive thyroid
- Parkinson’s disease
Some experts have suggested that people with essential tremor may have a higher risk of developing other neurological conditions, such as Parkinson’s disease and hearing loss, especially if the tremor starts after the age of 65 years.
There may also be a higher risk of developing Alzheimer’s disease, according to NORD.
Some factors can make essential tremor more pronounced. These include:
- stress and anxiety
- hunger or low blood sugar
- caffeine consumption
- hot or cold temperatures
- tobacco use
Alcohol consumption can worsen tremor during a hangover, in the short term, and if a dependency develops, in the long term.
While a small study in 10 people found that tremor improved
There is no test for essential tremor. Instead, a doctor tends to:
- look at the person’s symptoms
- ask about their personal and family medical histories
- ask about any medications
- perform a physical examination
- do some tests, if appropriate, to rule out other conditions
To evaluate the tremor, the doctor
- pour and drink water
- touch their fingers to their nose
- hold their hands out in front of them
- draw a spiral
They will also assess the person’s:
- muscle strength and tone
- tendon reflexes
- posture and coordination
- ability to feel certain sensations
Tests to rule out other conditions might include a blood test to check levels of thyroid hormones and an MRI scan of the brain.
If essential tremor is mild, it may not need treatment. If it affects the quality of life or ability to do everyday tasks, a doctor may recommend one of the following approaches.
Medications for essential tremor
The following types of medication may reduce the tremor:
- beta-blockers, such as propranolol (Inderal), atenolol (Tenormin), sotalol (Betapace), or nadolol (Corgard)
- calcium channel blockers, such as nimodipine (Nimotop)
- anticonvulsants, such as primidone (Mysoline), topiramate (Topamax), and gabapentin (Neurontin)
- antianxiety medications, such as alprazolam (Xanax) and clonazepam (Klonopin)
Doctors most commonly prescribe propranolol or primidone, although 30–50% of people report having no benefit from these drugs.
Botox injections might also help. Muscle weakness is a possible side effect, but this is usually temporary.
Deep brain stimulation
A doctor may recommend deep brain stimulation (DBS). This involves using imaging techniques to locate the thalamus, a part of the brain that helps control movement.
A surgeon then inserts an electrode into the area and an implantable pulse generator under the skin of the chest. The two are connected with a small wire. The generator helps control the tremor by sending electric currents to the brain.
Complications of the procedure include:
- pain after surgery
- bleeding and swelling in the brain
DBS may help with tremor, but it will not cure nerve damage or stop it from getting worse. Also, it will not improve dementia or other types of cognitive decline.
Another surgical option is a thalamotomy. This involves making a small lesion in the thalamus to block the brain activity that is causing the tremor.
Making this incision on one side can help reduce the tremor on one side of the body. Operating on both sides is not possible, as it could lead to severe disability.
Newer techniques are less invasive and include using focused radiation or ultrasound to cause the same lesion as the surgery.
The risk of complications, however, outweighs the benefits for most people. For this reason, doctors do not often recommend the surgery and always recommend medication first.
Physical therapy to boost physical awareness may improve the quality of life for people with essential tremor.
While little research supports this approach, a
A 61-year old male who had previously undergone DBS participated in training that focused on balance, functional movement, and stability. After 14 weeks, the participant saw improvements in walking speed, balance, and performance of daily tasks. The risk of falls also decreased.
Essential tremor is a neurological condition and movement disorder that leads to trembling. It often affects the hands and head, but it can affect other areas, such as the limbs and trunk. Experts do not know exactly why it develops, but genetics may play a role.
If symptoms are mild, treatment may not be necessary. If the tremor affects the quality of life, a doctor may suggest medication, physical therapy, surgery, or a combination.