A tremor is a series of involuntary muscle contractions that cause shaking. Many people associate tremors with Parkinson’s disease, but they’re also commonly caused by another movement disorder called essential tremor.
Essential tremor affects about 7 million people in the United States. It’s at least eight times more common than Parkinson’s. The hallmark symptom of essential tremor is a tremor in both hands and arms.
Parkinson’s disease is a progressive condition that causes problems with movement. It affects about
Not all people with Parkinson’s develop a tremor. But when Parkinsonian tremors do appear, they’re usually seen during rest and at a slower frequency than tremors caused by essential tremor.
It’s often difficult to distinguish Parkinson’s disease from essential tremor, especially in the early stages of the disease.
Read on to learn about the similarities and differences between these two conditions that help medical professionals tell them apart.
According to the National Institute of Neurological Disorders and Stroke, onset most commonly occurs after the age of 40. It generally slowly gets worse over time, but it does stabilize in some people.
The primary symptom of essential tremor is small but rapid tremors that:
- occur mostly during actions
- usually affect both sides of your body
- generally affect one side more
- worsen during periods of stress, fatigue, and periods of strong emotion
- predominately affect your hands and arms
- cause difficulty with fine motor movement, such as holding utensils
Diagnosis of essential tremor is made clinically. This means your doctor exams your medical history, your symptoms, and the results of a physical exam to look for signs of essential tremor. No single test can be used to make the diagnosis.
To rule out other conditions, your doctor may order more tests, such as:
- neurological exam
- imaging test
- blood test
- urine test
Parkinson’s disease is a progressive condition that causes trouble with movement. It’s caused by the death of cells in a part of the brain called the substantia nigra. This part of your brain produces the neurotransmitter dopamine.
In some cases, specific genetic mutations are linked to the development of Parkinson’s. But more often, it seems to appear randomly. It’s thought that environmental factors such as exposure to pesticides, herbicides, or air pollution may contribute, but more evidence is needed to understand the potential link.
According to the National Institute on Aging, Parkinson’s most commonly develops in people over the age of 60 and affects men about 50 percent more often than women.
The primary symptoms of Parkinson’s are:
- tremor, most commonly in upper limbs, jaw, or head
- muscle stiffness and rigidity
- slowness of movement
- problems with balance and coordination
Other complications that may develop include:
- trouble swallowing
- difficulty speaking
- loss of bladder control
- sleep disruptions
- development of oily or flaky skin
Medical professionals can’t use any single test to diagnose Parkinson’s. Like with essential tremor, doctors make the diagnosis by examining your medical history, symptoms, and the results of neurological and physical exams.
Blood tests and imaging techniques such as MRI can help rule out other conditions. A dopamine transported scan (DaTscan) can help identify changes in dopamine levels in your brain that may help your doctor diagnose Parkinson’s.
Here are some key differences between essential tremor and Parkinson’s disease:
- Development of tremor. Tremor is the key symptom of essential tremor. About
75 percentof people with Parkinson’s develop tremor.
- Type of tremor. People with Parkinson’s usually have tremors when they’re at rest. People with essential tremor generally have tremors during movement.
- Frequency of tremor. The movements of essential tremor generally occur at a higher frequency than Parkinsonian tremors. Parkinson’s usually causes higher magnitude tremors, but the magnitude of essential tremor movements is more variable.
- Duration of tremor. A
2016 studyfound that people with essential tremor reported three times as many waking hours experiencing tremor than people with Parkinson’s disease.
- Family history. Studies report a family history in about
halfof cases of essential tremor but only about 10 to 15 percent of Parkinson’s cases.
- Other symptoms. Parkinson’s is more likely to cause trouble balancing and walking as well as stiff muscles and slow movements.
- Neurological pathway. Parkinson’s disease is associated with the loss of cells in a part of the brain called the substantia nigra that produces dopamine. It’s thought that changes to the brain stem, and possibly cerebellum, play a role in developing essential tremor.
- Progression. Parkinsonian tremors generally affect one side of the body first and then spread to the other side. Essential tremor generally affects both sides in the beginning.
There’s currently no known cure for essential tremor. Treatment revolves around reducing symptoms. The beta-blocker propranolol and anticonvulsant primidone are the first-line therapies.
If these medications don’t work or aren’t well tolerated, your doctor may recommend:
- other medications
- deep brain stimulation
- focused ultrasound
- radiosurgical gamma knife thalamotomy (surgery of the thalamus gland)
- botulinum toxin injections
For some people, applying weights to the wrists can dampen tremors to provide relief. Doctors usually recommend people avoid alcohol and caffeine as well as minimize stress.
Medications often help manage Parkinson’s symptoms. Over time, the benefits of medications tend to wear off. They often help manage symptoms for
The medication carbidopa/levodopa is the primary treatment for Parkinson’s. Other medications include:
- dopamine agonists
- COMT inhibitors
- MAO-B inhibitor
Researchers are also continuing to examine the potential benefits of a procedure called deep brain stimulation.
There’s no known cure for Parkinson’s disease or essential tremor, but treatment in the early stages can improve your outlook and give you the best chance of slowing their progression.
The outlook for people with essential tremor varies greatly.
Essential tremor usually starts gradually and progresses at a rate of about 1.5 to 5 percent per year. Although not typical, symptoms can stop progressing in some people. It’s not a life threatening disease, but tremors can make daily tasks such as eating or getting dressed difficult.
Many people with essential tremor only experience mild symptoms that don’t affect their day to day too much. People with essential tremor have the
People with essential tremor have about a four times greater chance of developing Parkinson’s than somebody in the general population. Researchers are continuing to examine the link between the two conditions.
Parkinson’s disease gets progressively worse over time. But many people continue to have a good quality of life when it’s treated in the early stages. It’s important to seek medical attention as soon as you suspect that you or a loved one may have Parkinson’s.
For people with Parkinson’s disease that doesn’t impair their ability to think, they have a comparable life expectancy as anybody else.
Most people with Parkinson’s experience disability within