Medicine – Benign Essential Tremor

Essential tremor is a common movement disorder characterised primarily by an action tremor, meaning the tremor appears during voluntary movement or while maintaining a posture against gravity. It is usually bilateral and most often affects the hands and forearms, but the head and voice may also be involved.

The older term “benign essential tremor” is still encountered, but essential tremor is preferred because the condition can sometimes cause significant functional disability.

1. Tremor with Movement

The tremor of essential tremor is typically an action or postural tremor.

It is most noticeable when the patient:

Holds the arms outstretched.

Writes.

Uses cutlery.

Drinks from a cup.

Performs other fine hand movements.

A classic resting tremor is not the dominant feature.

2. Difference from Parkinson Tremor

Essential tremor is easiest to distinguish from Parkinson disease by the timing of the tremor.

Essential tremor → tremor mainly with posture or movement.

Parkinson disease → tremor classically occurs at rest.

Parkinson tremor is also often initially asymmetric and accompanied by bradykinesia and rigidity, whereas essential tremor usually lacks these Parkinsonian features.

3. Distribution

The hands and arms are most commonly affected.

The tremor may also involve:

Head.

Voice.

Less commonly, other body regions may be involved.

Head tremor may appear as repeated “yes-yes” or “no-no” movements.

4. Bilateral Tremor

Essential tremor is typically bilateral, although one side may initially be more noticeable than the other.

This differs from Parkinson disease, which often begins clearly asymmetrically.

5. Inheritance

Essential tremor often has a strong familial component.

Many families show an autosomal dominant pattern of inheritance, although the genetics are heterogeneous and not every patient has an affected relative.

Therefore, a positive family history supports the diagnosis but is not required.

6. Effect of Stress

The tremor commonly becomes worse with:

Anxiety.

Emotional stress.

Fatigue.

Sleep deprivation.

Stimulants such as excess caffeine.

Patients may therefore notice substantial day-to-day variation in severity.

7. Effect of Alcohol

A characteristic historical feature is temporary improvement after a small amount of alcohol.

This can be a useful diagnostic clue.

However, alcohol should not be recommended as a treatment because of tolerance, dependence, rebound worsening, and other health risks.

8. Neurological Examination

In otherwise typical essential tremor, the remainder of the neurological examination is generally normal.

There should not be prominent:

Bradykinesia.

Rigidity.

Cerebellar signs.

Focal neurological deficits.

The presence of these findings suggests another diagnosis.

9. Diagnosis

Essential tremor is primarily a clinical diagnosis.

The history and examination should establish a persistent bilateral upper-limb action tremor and exclude more likely alternative causes.

Investigations are usually directed toward excluding secondary causes when the presentation is atypical.

10. Secondary Causes to Exclude

Other causes of tremor include:

Hyperthyroidism.

Drug-induced tremor.

Excess caffeine or stimulants.

Alcohol withdrawal.

Parkinson disease.

Cerebellar disorders.

Dystonic tremor.

Therefore, the diagnosis should not be made solely because the tremor improves with alcohol.

11. Propranolol

Propranolol, a non-selective beta-blocker, is a major first-line treatment when the tremor causes functional impairment.

It can reduce tremor amplitude and improve tasks such as writing, eating, and drinking.

The old statement that only about 30% respond is too restrictive; response rates vary, and many patients obtain at least partial benefit.

12. Primidone

Another important first-line treatment is primidone.

Primidone is an anticonvulsant that can significantly reduce essential tremor and is often used when propranolol is ineffective, contraindicated, or not tolerated.

Therefore, the main medications to remember are:

Propranolol.

Primidone.

13. When Propranolol May Be Unsuitable

Because propranolol blocks beta receptors, it may be unsuitable in some patients, particularly those with:

Asthma.

Marked bradycardia.

Certain conduction abnormalities.

Treatment therefore needs to be individualised.

14. Other Treatment Options

If first-line treatment is inadequate, specialist management may include other medications or procedural treatments.

For severe disabling medication-resistant tremor, options may include:

Deep brain stimulation.

Focused ultrasound thalamotomy in selected patients.

These are generally reserved for significant refractory disease.

15. Essential Tremor – Note Form

Type of tremor: action/postural tremor.

Rest tremor: not the classic dominant feature.

Distribution: mainly hands and arms; head and voice may also be affected.

Inheritance: often autosomal dominant.

Stress: worsens tremor.

Alcohol: may temporarily improve tremor but is not a recommended treatment.

Neurological examination: otherwise usually normal.

First-line treatment: propranolol or primidone when symptoms are functionally troublesome.

Key Clinical Pattern

Remember essential tremor as:

Bilateral action tremor + hands/head involvement + worse with stress + may improve transiently with alcohol.

The easiest distinction is:

Essential tremor → action/postural tremor.

Parkinson disease → resting tremor + bradykinesia + rigidity.

And the key treatment pair is:

Propranolol or primidone.

1. Tremor with Movement The tremor of essential tremor is typically an action or postural tremor. It is most noticeable when the patient: Holds the arms outstretched. Writes. Uses cutlery. Drinks from a cup. Performs other fine hand movements. A classic resting tremor is not the dominant feature. 

2. Difference from Parkinson Tremor Essential tremor is easiest to distinguish from Parkinson disease by the timing of the tremor. Essential tremor → tremor mainly with posture or movement. Parkinson disease → tremor classically occurs at rest. Parkinson tremor is also often initially asymmetric and accompanied by bradykinesia and rigidity, whereas essential tremor usually lacks these Parkinsonian features. 

3. Distribution The hands and arms are most commonly affected. The tremor may also involve: Head. Voice. Less commonly, other body regions may be involved. Head tremor may appear as repeated “yes-yes” or “no-no” movements. 

4. Bilateral Tremor Essential tremor is typically bilateral, although one side may initially be more noticeable than the other. This differs from Parkinson disease, which often begins clearly asymmetrically. 

5. Inheritance Essential tremor often has a strong familial component. Many families show an autosomal dominant pattern of inheritance, although the genetics are heterogeneous and not every patient has an affected relative. Therefore, a positive family history supports the diagnosis but is not required. 

6. Effect of Stress The tremor commonly becomes worse with: Anxiety. Emotional stress. Fatigue. Sleep deprivation. Stimulants such as excess caffeine. Patients may therefore notice substantial day-to-day variation in severity. 

7. Effect of Alcohol A characteristic historical feature is temporary improvement after a small amount of alcohol. This can be a useful diagnostic clue. However, alcohol should not be recommended as a treatment because of tolerance, dependence, rebound worsening, and other health risks. 

8. Neurological Examination In otherwise typical essential tremor, the remainder of the neurological examination is generally normal. There should not be prominent: Bradykinesia. Rigidity. Cerebellar signs. Focal neurological deficits. The presence of these findings suggests another diagnosis. 

9. Diagnosis Essential tremor is primarily a clinical diagnosis. The history and examination should establish a persistent bilateral upper-limb action tremor and exclude more likely alternative causes. Investigations are usually directed toward excluding secondary causes when the presentation is atypical. 

10. Secondary Causes to Exclude Other causes of tremor include: Hyperthyroidism. Drug-induced tremor. Excess caffeine or stimulants. Alcohol withdrawal. Parkinson disease. Cerebellar disorders. Dystonic tremor. Therefore, the diagnosis should not be made solely because the tremor improves with alcohol. 

11. Propranolol Propranolol, a non-selective beta-blocker, is a major first-line treatment when the tremor causes functional impairment. It can reduce tremor amplitude and improve tasks such as writing, eating, and drinking. The old statement that only about 30% respond is too restrictive; response rates vary, and many patients obtain at least partial benefit. 

12. Primidone Another important first-line treatment is primidone. Primidone is an anticonvulsant that can significantly reduce essential tremor and is often used when propranolol is ineffective, contraindicated, or not tolerated. Therefore, the main medications to remember are: Propranolol. Primidone. 

13. When Propranolol May Be Unsuitable Because propranolol blocks beta receptors, it may be unsuitable in some patients, particularly those with: Asthma. Marked bradycardia. Certain conduction abnormalities. Treatment therefore needs to be individualised. 

14. Other Treatment Options If first-line treatment is inadequate, specialist management may include other medications or procedural treatments. For severe disabling medication-resistant tremor, options may include: Deep brain stimulation. Focused ultrasound thalamotomy in selected patients. These are generally reserved for significant refractory disease. 

15. Essential Tremor – Note Form Type of tremor: action/postural tremor. 

Rest tremor: not the classic dominant feature. 

Distribution: mainly hands and arms; head and voice may also be affected. 

Inheritance: often autosomal dominant. 

Stress: worsens tremor. 

Alcohol: may temporarily improve tremor but is not a recommended treatment. 

Neurological examination: otherwise usually normal. 

First-line treatment: propranolol or primidone when symptoms are functionally troublesome. 

Key Clinical Pattern Remember essential tremor as: Bilateral action tremor + hands/head involvement + worse with stress + may improve transiently with alcohol. The easiest distinction is: Essential tremor → action/postural tremor. Parkinson disease → resting tremor + bradykinesia + rigidity. And the key treatment pair is: Propranolol or primidone.