creation date: 2026-06-05 18:55
tags: Pathologies
Essential Tremor
Background
Definitions
Essential tremor (ET) is a common action tremor in adults. It has an overall prevalence of 1% and 5% in adults over 60.
Familial tremor refers to ET with a family history.
Pathogenesis
The pathogenesis is largely unknown but there appears to be:
- Strong genetic component
- Possible dysfunction with cerebellothalamic pathway
Clinical Presentation
Signs & Symptoms
ET is an action tremor:
- Moderate to high frequency (6-12 Hz); varies from low-amplitude, high frequency with postural to large-amplitude, low frequency with particular movements
- Bilateral, may be slightly asymmetric
- Affects hands and arms; also head, voice, and less commonly face/trunk
- Most noticeable with posture holding and targeted limb movements
- Immediately apparently with action (contrast: latency with PD)
Exacerbating factors include:
- Anxiety, stress, excitement
- Caffeine
While the tremor is the primary manifestation, in some cases, additional neurologic findings may include:
- Difficulty with tandem gait
- Mild cognitive impairment
- Slight overflow to rest posture
History & Physical Exam
History should include:
- Age on onset
- Degree of progression
- Involved body parts
- Activities most affected and details of disability (eg. embarrassment)
- Exacerbating and relieving factors
- Family history
A neurologic exam and focused exam of the tremor is performed.
Diagnosis
Criteria
Diagnosis is made clinically with the following criteria:
- Bilateral upper limb action tremor, with or without head or voice tremor
- Normal neurologic examination aside from tremor
- Exclusion of other causes (eg. medications, hyperthyroidism, or metabolic abnormality)
The formal diagnostic criteria from the International Parkinson and Movement Disorder Society (IPMDS) adds:
- At least three years in duration
- Categorization of “ET plus” in causes of additional “soft” neurologic signs
Work-up
Laboratory tests
Tests are done to exclude common causes of enhanced physiologic tremor:
- Electrolytes (including calcium)
- Liver function tests
- Thyroid function tests
- Studies for Wilson disease
Brain imaging
Imaging for the brain (MRI or CT) is not required but consider if:
- Focal neurologic findings
- Sudden onset of symptom suggestive of structural cause
Dopamine transporter imaging (DaTscan), which reliably distinguishes ET, may be helpful if:
- Uncertain diagnosis of ET vs. PD
- Signs of PD that does not respond to levodopa
- Possible candidate for deep brain stimulation
Differential
Discussed separately.
Red Flags / Complications
ET can be a source of disability, particularly socially. ET will worsen over time.
Management
The goals of management are to reduce tremor severity, which may or may not completely suppress the tremor. There are no disease modifying treatments.
Optimization of Exacerbating/Mitigating Factors
Medications and substances that exacerbate should be discontinued if possible. Alcohol may reduce tremor and some patients may find this useful in social settings.
Pharmacological
Drug therapy should be offered to patients with intermittent or persistent disability caused by the tremor.
Patients with frequent/daily symptoms
First-line options include:
- Propranolol 60-80 mg daily (usually divided to 2-4 times per day)
- Primidone 25 mg daily qHS
Second-line options include:
- Propranolol plus primidone
- Topiramate
- Benzodiazepine (caution: abuse/dependence)
- Gabapentin (limited data)
Patients with situational exacerbations
Use of medication should be individualized and weighed against side effects. Consists of an anticipatory treatment of low-dose propranolol.