Essential tremor: It’s the most common movement disorder, but many people have never heard of it.
Essential tremor is a neurological condition that causes uncontrollable shaking. While it is often confused with Parkinson’s disease, it is actually a different condition, said Hae-Young Hawong, DO, PhD, a neurologist with Yale New Haven Health who specializes in movement disorders. Dr. Hawong is also an assistant professor of Neurology at Yale School of Medicine.
“While essential tremor and Parkinson’s share similarities, they differ in origin, symptoms, progression and treatment. Understanding the distinctions is crucial for accurate diagnosis and effective management,” Dr. Hawong said.
Essential tremor vs. Parkinson’s disease: Key differences
Essential tremor is approximately eight times more common than Parkinson’s disease, affecting an estimated seven to 10 million Americans. Both are movement disorders, but there are differences between the two.
- Type of tremor: Essential tremor is typically an “action” tremor, which means it occurs when you are using your muscles (i.e. writing, eating or drinking from a cup). They may worsen with emotional stress, fatigue, caffeine or extreme temperatures. Parkinson’s disease tremors are more noticeable when the muscles are relaxed.
- Affected areas: Essential tremor mainly involves the hands, head and voice. Parkinson's disease tremors usually start in the hands and can affect the legs, chin and other parts of the body.
- Progression: Essential tremor can slowly worsen over time; in its advanced stage, severe shaking may significantly interfere with daily activities and lead to frustration and social embarrassment. Parkinson's disease is a progressive neurodegenerative disorder that is more likely to cause additional symptoms (i.e. muscle rigidity, balance issues, sleep disturbances and mood changes).
- Age of onset: While essential tremor can appear at any age and has been diagnosed as early as childhood, it typically begins between the ages of 40-50. Parkinson's disease, which is caused by loss of dopamine-producing neurons in the brain, is most often diagnosed after age 60.
“It’s a clinical diagnosis,” Dr. Hawong said. “Each disorder has a specific pattern and specific presentation of symptoms. That’s why it’s important to do a clinical history.”
What causes essential tremor?
The exact cause of essential tremor is unclear, but genetics appear to play a major role — about 50 percent of cases are hereditary. “Compared to Parkinson’s, essential tremor has a strong family history. However, we still don’t know the specific gene mutation,” Dr. Hawong said.
Treatments for essential tremor
Current treatment options for essential tremor include a combination of medications, therapies and procedures. “Medications are the first line of treatment, and we have several different ones that we can try,” Dr. Hawong said. Lifestyle adjustments such as reducing caffeine, managing stress and occupational or physical therapy may also be recommended.
If medications are not successful in reducing tremors, other treatment options include deep brain stimulation (DBS) and high-intensity focused ultrasound (HIFU).
In DBS, the most common surgical treatment for essential tremor, electrodes are implanted into select areas of the brain. When stimulated by a battery-operated device, these electrodes influence the faulty communication between brain regions, helping to relieve the symptoms of essential tremor and other movement disorders.
Several studies, including those conducted by the neurology team in the Movement Disorders Program at Yale New Haven, indicate DBS can provide moderate or significant tremor reduction in up to 90 percent of patients and often improves daily function dramatically.
In addition to DBS, Yale New Haven Health also offers high-intensity focused ultrasound (HIFU) as a treatment for essential tremor. This procedure uses ultrasound waves guided by magnetic resonance imaging to treat a specific area in the brain that causes tremors.
“Focused ultrasound is minimally invasive, does not involve surgery and is completed as an outpatient procedure,” Dr. Hawong said. “Many patients experience immediate tremor reduction right after the procedure, and clinical studies report improvement in up to 75 percent of patients for as long as five years.”
Currently HIFU is performed only at Greenwich Hospital. The procedure will also be available at the Adams Neuroscience Center at Yale New Haven Hospital when it opens in 2027.
Talk to your doctor
When should you be concerned about tremors? Dr. Hawong recommends talking with your primary care physician if you notice tremors that are bothering you or impacting your activities.
“Many people worry when they notice tremors and assume the worst,” she said. “But not every tremor is related to a movement disorder like essential tremor or Parkinson’s. It’s normal to experience physiologic tremors when we drink too much coffee or energy drink, when we are angry or when we are anxious. Many medications also can cause tremors. Your doctor can evaluate you and eliminate other potential factors, and if needed provide a referral to a neurologist at Yale New Haven who will determine the underlying cause and provide appropriate management strategies.”
Learn more about High Intensity Focused Ultrasound.
Learn more about the Adams Neuroscience Center.
