Essential Tremor in Adult Patients

Last updated March 15, 2022

Overview/Background/Prevalence

Overview/Background/Prevalence

  • Essential Tremor (ET) is one of the most common movement disorders. It can occur at any age, but is most common in people age 40 and older where incidence increases with each decade. ET affects up to 5% of people over the age of 60.
  • Age and family history are the two greatest risk factors for ET.
  • ET is typically a slowly progressive condition with patients often having tremor for many years prior to seeking treatment.
  • ET most commonly affects the hands but can affect the head and voice. Less commonly, the legs, trunk, jaw, and other facial muscles are involved.
  • Patients report a beneficial effect of alcohol about 60% of the time.
  • Many patients with ET have a family history of tremor (50%+). Despite this, while a few genes have been associated with ET, genetic testing is not currently available.
  • ET is commonly misdiagnosed, and often confused with Parkinson’s disease (PD) or dystonia.

Assessment/Screening

Assessment/Screening

Table 1. Examination for Essential Tremor

Area Comments
Limbs

Typically seen when holding a limb against gravity (arms outstretched, wing-beating) or with movement (finger to nose).

These items together are called “action tremor,” reflecting the fact that ET typically occurs during movement and typically affects the upper extremities.

Head Typically seen as a side to side shaking of the head (“no-no” tremor), but can occur in an up and down motion (“yes-yes”) or can be mixed.
Voice The voice is evaluated by listening to speech but also by having the patient hold a prolonged “ahhh” or “eee.”
Facial Muscles Examined by having the patient purse the lips or squeeze the eyelids.
Tasks Patient can be observed during functional tasks such as writing, drawing, pouring water, drinking from a cup.
  • History should be taken to understand how tremor impacts daily living and function, to determine if treatment is indicated.
  • Activities to ask about include eating, drinking, writing, hygiene, dressing, work, and hobbies.
  • The social disability/stigma and embarrassment with ET can be significant, so this should be discussed.
  • Neuroimaging to measure dopamine uptake (DaTscan) can be done if there is suspicion of underlying PD.
  • Examination of the patient includes assessment of the various parts of the body that can be affected.

Differential Diagnosis

Differential Diagnosis

Parkinson's Disease

There are many red flags that suggest the patient may be developing PD, which is the diagnosis most often confused with ET.
  • Aspects of the tremor that suggest PD include unilateral tremor onset and notable rest tremor.
  • Rest tremor often appears when the hand is down at the side, so walking should be part of a tremor evaluation.
  • Additionally, PD patients should demonstrate bradykinesia, and often rigidity of the limbs.
  • Bradykinesia can be assessed by watching the patient do rapid repetitive movements such as finger tapping, hand opening/closing, and foot tapping.
  • Patients with PD may have prodromal non-motor symptoms such as hyposmia and REM sleep behavior disorder, so these should be elicited.

Medications and Other Causes of Tremor

  • The medication list should be reviewed carefully since medications such as stimulants, antidepressants, antipsychotics and many immunosuppressants can cause tremor.
  • While most medications trigger tremor in a predictable dose-related fashion, there are some, like valproic acid and amiodarone, that can trigger tremor even after long-standing low-dosage exposure.
  • When diagnosing ET, consider ruling out thyroid issues (e.g. hyperthyroidism) and metabolic disorders (e.g. B-12 deficiency).
  • Also consider ruling out dystonic tremor, especially if tremor is present in or isolated to the head. Dystonia and ET are two movement disorders that may occur independently or coexist.

ET Plus

There are several soft signs that can be seen with ET that are now termed “ET Plus.”
  • For instance, many people with very long-standing ET may develop gait ataxia and rest tremor.
  • Dystonic features (subtle posturing of the hands or head) can be seen in some people with ET.
  • At this time, it is not known whether these neurological disorders are distinctly different from classical ET.

Table 2. Comparing Signs/Symptoms of ET and PD

Essential Tremor Parkinsonian Tremor
Most commonly affects upper limbs, head, voice Most commonly affects upper limbs and less commonly lower limbs and jaw. Voice and head almost never affected
Typically bilateral Begins unilateral and generally progresses to bilateral
Tremor primarily postural and kinetic (action tremor), rarely at rest Tremor primarily at rest may have postural tremor (re-emergent), rarely kinetic
4–12 Hz tremor 3–6 Hz tremor
Tremor is primary symptom – slowness, stiffness, walking and balance problems are not commonly seen. Slow movements (bradykinesia, rigidity (stiffness), and problems with walking or balance
Family history of tremor reported in the majority of patients Rarely a family history (<20%)
Onset most common after 40 but can occur at any time in the lifespan Average onset around 60 years, can be any time throughout adulthood
Alcohol often improves tremor Alcohol does not improve tremor
Worsens with stress/emotion Worsens with stress/emotion
About 8× more common than PD Much less common than ET
DaTscan normal DaTscan abnormal
Handwriting often large and tremulous Handwriting often micrographic and not tremulous
6731

Management

Management

Non-Pharmacological/Non-Surgical Treatment Options

Wrist-worn Non-invasive Stimulation (Cala Trio)

  • Cala Trio is an individualized, re-chargeable, non-invasive wrist-worn device to reduce tremor in a targeted arm. It provides electrical stimulation to the median and radial nerves through electrodes placed on the inside of a wrist band. This stimulation therapy is called transcutaneous afferent patterned stimulation (TAPS).
  • Cala Trio was cleared by the Food and Drug Administration (FDA) in 2018, and is indicated in adults with essential tremor to provide transient relief of hand tremors following stimulation.
    • The wrist band device is worn for 40 minutes, after which 64% of patients reported having persistent relief for an average of 94 minutes, and 54% of patients experienced ≥50% improvement in tremor power.
    • When starting therapy, patients should choose an activity (e.g. eating) and use Cala Trio 20–40 minutes prior. This usage should continue on-demand for at least 2 weeks to determine benefits.
    • A typical charge will last for approximately 5 sessions. It takes approximately 3–4 hours to fully charge the device.
    • It can be used with or without pharmacological therapies.
  • Cala Trio is contraindicated in patients with implanted electrical devices such as a pacemaker, defibrillator, or deep brain stimulation device; patients with a seizure disorder; pregnant women; and in persons with skin irritations, open wounds, or lesions on the wrist.

Pharmacological Treatment Options

  • It has been estimated that 30–60% of persons with ET who tolerate current pharmacological treatment options have a reduction in tremor.
    • Those that do respond to medications tend to have a 30–50% reduction in tremor.
  • Tremor rarely completely resolves with medication.
  • Limb tremor is generally the targeted tremor and tends to have a better and more consistent response than head or voice tremor.

Table 3. Currently Recommended Pharmacological Treatments for ET

Drug Class Titration Common Side Effects
Propranolol
(the only FDA-approved medication for ET)
(Level A)
Beta-blockera
  • May be used PRN: 10–40 mg
  • Start with divided doses of 10–60 mg/day (10 mg in older patients)
  • Slowly titrate up to 120 mg/day as needed
  • May slowly increase to 320 mg/day if needed
  • Do not abruptly stop
Lightheadedness, bradycardia, fatigue, impotence, depression, nausea, weight gain, rash, diarrhea
Propranolol Long Acting (Level A) Beta-blocker
  • Start with 60 mg/day
  • Slowly titrate to 120 mg/day
  • May slowly titrate higher if needed
  • Do not abruptly stop
Same as propranolol
Primidone (Level A) Anticonvulsant
  • Start at 12.5 or 25 mg at bedtime
  • Increase to 50 mg at bedtime after one week
  • Increase by 50 mg/week up to 250 mg/day as needed
  • May slowly increase to higher doses up to 750 mg/day if tolerated
  • May be taken at bedtime due to sedation or in divided doses if tolerated
Sedation, fatigue, nausea, poor balance, dizziness, flu-like symptoms
Propranolol and primidone may be used in combination if tremor not well controlled with either alone
Gabapentin Monotherapy (Level B)
Adjunct
(insufficient evidence)
Anticonvulsant
  • Start with 300 mg three times a day
  • Increase to 1800 mg/day as needed
  • May increase up to 3600 mg/day
  • Stronger evidence for monotherapy than for adjunctive therapy
Sedation, fatigue, dizziness, ataxia, nervousness, irritability, nausea, shortness of breath
Topiramate (Level B) Anticonvulsant
  • Start with 25–50 mg at bedtime
  • Slowly increase up to 150–300 mg/day
  • May increase up to 400 mg/day
Dizziness, disorientation, memory problems, loss of appetite, weight loss, paresthesia, fatigue, nausea, somnolence, headache
Alprazolam (Level B)
Clonazepam (Level C)
Diazepam
Lorazepam
Benzodiazepines
  • Use as directed and titrate as needed
  • May be beneficial in those with anxiety
  • Caution regarding addiction
Drowsiness, fatigue, lightheadedness, dizziness, depression, fatigue, loss of coordination, memory loss, confusion

a Small studies have shown benefit from other beta-blockers such as atenolol (50–150 mg/day; Level B — probably effective), sotalol (75–200 mg/day; Level B — probably effective), and nadolol (120–240 mg/day; Level C — possibly effective), all of which could be tried in patients with ET

Acetazolamide, flunarizine, isoniazid, levetiracetam, pindolol, methazolamide, mirtazapine, nifedipine, trazodone, verapamil, and 3,4-diaminopyridine are not recommended for treatment of limb tremor in ET (AAN Guidelines).

There is insufficient evidence to make recommendations regarding the use of amantadine, clonidine, clozapine, gabapentin (adjunct therapy), glutethimide, L-tryptophan/pyridoxine, metoprolol, nicardipine, olanzapine, phenobarbital, pregabalin, quetiapine, theophylline and zonisamide in the treatment of limb tremor in ET (AAN Guidelines).


Surgical Treatment Options

Patients whose tremor is not controlled by pharmacological therapies may be candidates for surgical treatment options that include deep brain stimulation (DBS), focused ultrasound (FUS) and gamma knife radiosurgery (GKR).

Table 4. Surgical Treatment Options

Deep Brain Stimulation (DBS) Focused Ultrasound (FUS) Gamma Knife Radiosurgery (GKR)
Surgical Method Stimulation: an electrode is placed in the brain and connected to a pulse generator typically located in the chest to provide electrical stimulation to the brain. Ablation: uses multiple ultrasound beams to destroy tissue in the brain. Ablation: uses multiple radiation beams to destroy tissue in the brain
Brain Site VIM nucleus of the thalamus VIM nucleus of the thalamus VIM nucleus of the thalamus
Status During Surgery Awake or asleep under general anesthesia Awake Awake
Time to Benefit Immediate Immediate Weeks to months
Pros
  • No destruction of brain tissue
  • Stimulation can be adjusted to increase benefit or reduce side effects without further surgery
  • Device can be repositioned to increase benefit or reduce side effects
  • Can have bilateral procedures
  • Can be removed — reversible
  • Electrophysiologic confirmation of target
  • No hole in the skull
  • No device implanted in body
  • Does not require frequent follow-up
  • May be an option for patients with comorbidities and unable to undergo DBS
  • No hole in the skull
  • No device implanted in body
  • Does not require frequent follow-up
Cons
  • Requires periodic adjustments
  • Requires battery changes or re-charging
  • Foreign material implanted in body — increased risk of wound infection and other complications
  • Head partially shaved
  • Pre-existing cognitive issues could worsen
  • Unable to adjust to increase benefit or reduce side effects without further surgery
  • No bilateral procedures
  • Not reversible
  • Must be able to tolerate MRI
  • Head fully shaved
  • Pre-existing cognitive issues could worsen
  • Unable to adjust to increase benefit or reduce side effects without further surgery
  • No bilateral procedures
  • Not reversible
  • Long-term complications may develop as effects of radiation spreads
  • May take months to see an effect
  • Pre-existing cognitive issues could worsen
Outcomes
  • 50–75% tremor reduction (unilateral)
  • 65–80% tremor reduction (bilateral)
35–75% tremor reduction (unilateral)
  • Rarely used in ET
  • 3–60% tremor reduction (unilateral)
Complications
  • Surgical (<5%) — intracranial hemorrhage, infection, edema
  • Device related (<5%) — hardware malfunction, misplaced or migrating leads, erosion
  • Stimulation related — paresthesia, gait disturbance, dysarthria
Edema, headache, paresthesia, weakness, nausea, dysarthria, gait disturbances Edema, scalp irritation, headache, fatigue, nausea, weakness, dysarthria, confusion

Botulinum Toxins

  • Botulinum toxin is not currently approved by the FDA for the treatment of tremor.
  • General side effects of botulinum toxins include rash, pain, stiffness, cramping, hematoma, and paresthesia.
  • Reports have shown efficacy of botulinum toxin for upper limb, head, and voice tremor when the tremor is not responding to oral pharmacotherapies.
Table 5. Botulinum Toxins in Various Tremors
Area Comments
Upper Limb The greatest benefit has been shown to be between 6 and 16 weeks after the injections. Hand weakness is the most common side effect and is dose dependent. Focusing on the forearm wrist flexor instead of the extensor muscles significantly reduces weakness.
Head It is important to distinguish ET from dystonic tremor. Botulinum toxins have been shown to be beneficial for both dystonic and ET head tremor in the majority of patients. The benefit usually occurs after one week and continues for 8–12 weeks. The most common side effects are dysphagia, headache and neck weakness.
Voice 50–60% of patients have been reported to improve with botulinum toxin injections directed primarily at the vocal cord under electromyographic guidance or direct visualization with endoscopy. The most common side effects included weak voice, hoarseness, and breathy voice, all of which can last for several weeks.

Assistive Devices

  • According to the World Health Organization, assistive devices are tools which facilitate function.
  • Assistive devices can enhance participation in meaningful activities and well-being.
  • Assistive devices vary in complexity. These items can range from simple household items to those requiring advanced technology or software.
  • When considering assistive devices, a formal evaluation is the initial step to identify individual needs and preferences and to determine the supports required and and barriers to use of an assistive device.
  • A trial of the equipment is beneficial to determine effectiveness in meeting the individual’s goals.
  • An occupational therapist is able to assist with concerns related to participation in daily activities, a physical therapist for concerns involving mobility or coordination, and a speech/language pathologist for concerns related to communication.
  • Assistive devices (see Table 6 & 7) can be specific to the person, daily activity, or task.
  • Many of these devices are also referred to as adaptive equipment or daily living aids. They help individuals complete everyday activities, thereby improving their quality of life.

Table 6. Assistive Devices

Devices Description Attributes Considerations
Exoskeletons A wearable electromechanical device which detects rhythmic movements caused by the tremor and uses technology to produce a countermovement response Reduces tremor power (40–80%) while the device is worn

Cost, bulkiness of the device, and discomfort when wearing are factors

Level of evidence specific to efficacy of these devices remains low

Orthotics Act in parallel with the affected body part to reduce tremor amplitude Reduces tremor amplitude (up to 80%) when worn

Cost, availability, and bulkiness of the device are factors

Level of evidence specific to efficacy of these devices remains low

Handheld Devices Handheld devices with technology to counteract the motion of tremor Reduces movement (71–76%) with Active Cancellation of Tremor technology

Cost associated with devices

Works best for individuals with mild to moderate tremor

Limb Weights Weights of an assessed optimal amount applied to either arms or legs to reduce tremor Reduces tremor to improve function for some individuals Level of evidence specific to efficacy of these devices remains low

Table 7. Assistive Devices Specific to Daily Activities

Devices Examples Attributes Considerations
Dining Aids Weighted utensils, rocker knife, covered spoon, plate guard, high sided dish, non-skid pad/surface, insulated weighted cup with lid, two handled cup, long reusable straw
  • Intent of the intervention is to modify the activity or reduce the activity demand to enhance performance
  • A wide range of assistive devices exist
  • Household items can be useful tools
  • Many of the assistive devices are available through large retail stores, the local drug store, or online
  • Benefit from and preference for a particular device is specific to the individual
  • Many of the devices are specific to the stated activity and must be available whenever and wherever the individual completes the activity
  • Some individuals may perceive that using assistive devices reduces their satisfaction when completing the activity
  • Costs associated with obtaining assistive devices since they are not considered durable medical equipment
Grooming Aids Hands-free hair dryer mount or stand, electric razor, electric toothbrush, long handled comb, suction cup toothbrush for dentures, tabletop nail clipper
Dressing Aids Adapted clothing, magnetic button adaptors, weighted button aid and zipper pulls, elastic shoelaces
Bathing Aids Wall mounted shampoo and soap dispensers, wash mitt, shower chair
Cooking Aids Automatic jar opener, food processor, electric chopper, cut resistant gloves, adapted cutting board, pot stand
Writing Aids Weighted pen or pencil, steadying aid for writing implement, adapted pen
Computer/Communication Aids Mouse accessibility software, larger buttoned keyboard, keyguard, voice to text or text to speech software or phone application, fluency devices
Leisure Participation Aids Card holder, large buttoned universal remote, book holder

Figure 1. Overview of Management of Essential Tremor

Figure 1. Overview of Management of Essential Tremor

Patient Tools/Resources

Patient Tools/Resources

Patient/Clinician FAQ and Discussion Points

Q: What causes ET?
A: The cause of ET is currently unknown. A large percentage of persons with ET have a family history of the disorder.

Q: How is ET diagnosed?
A: There are no medical tests to confirm a diagnosis of ET. Generally, ET is diagnosed by ruling out other causes of tremor, including certain medications, Parkinson’s disease, and excessive stress or trauma.

Q: Is ET life-threatening?
A: While it can worsen over time, ET is not a life-threatening disorder. The severity of the tremor can vary from a barely noticeable tremor only present in situations of stress or anxiety, to a severe tremor that has a significant impact on activities of daily living.

Q: Can ET be “cured”?
A: There is currently no cure for ET; however there are a number of management approaches that can help improve quality of life.

Q: Which management approach is right for me?
A: Clinicians and patients should take a shared decision-making approach to identify which management strategies are right for each individual. Level of invasiveness, potential for side effects, efficacy, and cost can all be considered when deciding which approach(es) to start with.

Q: Will ET affect my ability to work?
A: It may. If your tremor is so severe that it disrupts your ability to work, you may qualify for federal disability benefits. The Social Security Administration administers two programs: Social Security Disability Insurance (SSDI) and Supplemental Security Income (SSI).

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Disclaimer

This pocket guide attempts to define principles of practice that should produce high-quality patient care. It is applicable to specialists, primary care, and providers at all levels. This pocket guide should not be considered exclusive of other methods of care reasonably directed at obtaining the same results. The ultimate judgment concerning the propriety of any course of conduct must be made by the clinician after consideration of each individual patient situation. Neither IGC, the medical associations, nor the authors endorse any product or service associated with the distributor of this clinical reference tool.