What are the treatment options for essential tremors?

Treatment of Essential Tremors

Start with propranolol (80-240 mg/day) or primidone as first-line therapy, as recommended by the American Academy of Neurology, with effectiveness in up to 70% of patients. 1

First-Line Pharmacological Treatment

Propranolol

• Propranolol is the most established medication for essential tremor, having been used for over 40 years with demonstrated efficacy 1
• Dosage range: 80-240 mg/day 1, 2
• Provides dual benefits in patients with both essential tremor and hypertension 1
• Contraindications include chronic obstructive pulmonary disease, bradycardia, or congestive heart failure 1, 2
• Common adverse effects: fatigue, depression, dizziness, hypotension, exercise intolerance, sleep disorders, cold extremities, and bronchospasm 1
• In elderly patients, excessive heart rate reduction may lead to serious adverse events 1

Primidone

• Equally effective first-line option alongside propranolol 1
• Clinical benefits may not become apparent for 2-3 months, so an adequate trial period is essential 1
• Therapeutic benefit can occur even when derived phenobarbital levels remain subtherapeutic, confirming primidone itself has anti-tremor properties 1
• Side effects: behavioral disturbances, irritability, and sleep disturbances, particularly at higher doses 1
• Women of childbearing age must be counseled about teratogenic risks (neural tube defects) 1

When to Initiate Treatment

• Only initiate medications when tremor symptoms interfere with function or quality of life 1, 3
• Essential tremor can cause greater impairment than Parkinson's disease in activities like writing, eating, drinking, and reading 3

Second-Line Pharmacological Options

If first-line agents fail or are not tolerated:

Alternative Beta-Blockers

• Nadolol: 40-320 mg daily 1
• Metoprolol: 25-100 mg extended release daily or twice daily 1
• Atenolol: limited evidence for moderate effect 1
• Timolol: 20-30 mg/day 1

Other Medications

• Gabapentin has limited evidence for moderate efficacy 1
• Carbamazepine may be used as second-line therapy, though generally not as effective as first-line options 1

Combination Therapy

• If either primidone or propranolol alone do not provide adequate control, they can be used in combination 4

Non-Pharmacological Approaches

Rhythm Modification Techniques

• Superimpose alternative rhythms on existing tremor and gradually slow movement to complete rest 1
• For unilateral tremor, use the unaffected limb to dictate a new rhythm to help entrain the tremor to stillness 1
• Use gross rather than fine movements, especially for activities like handwriting 1, 2
• Avoid cocontraction or tensing of muscles as this is unlikely to be a helpful long-term strategy 1

Lifestyle Modifications

• Avoid strenuous exercise before precision tasks 2
• Reduce caffeine consumption 2
• Implement stress reduction techniques 2

Important Pitfall

• Avoid prescribing aids and equipment in the acute phase, as they may interrupt normal automatic movement patterns 1
• If aids are necessary for safety, consider them short-term solutions with a plan to progress toward independence 1

Surgical Interventions for Medication-Refractory Tremor

Consider surgical therapies when medications fail due to lack of efficacy at maximum doses, dose-limiting side effects, or medical contraindications. 1

Treatment Algorithm for Surgical Candidates

For unilateral tremor or patients with medical comorbidities: Choose MRgFUS thalamotomy 1

• Shows sustained tremor improvement of 56% at 4 years 1, 3
• Lowest complication rate at 4.4% compared to radiofrequency thalamotomy (11.8%) and DBS (21.1%) 1, 3
• Early adverse effects include gait disturbance (36%) and paresthesias (38%), which decrease to 9% and 14% respectively by 1 year 1
• Serious adverse events are rare (1.6%), with most being mild or moderate (98.4%) and more than 50% resolving by 1 year 1
• Contraindications: patients unable to undergo MRI, skull density ratio <0.40, bilateral treatment needs, or contralateral to previous thalamotomy 1, 3
• Cannot be adjusted or reversed if complications occur 1

For bilateral tremor: Choose Deep Brain Stimulation (DBS) 1

• Provides adjustable, reversible tremor control that can be optimized over time 1
• Preferred for relatively young patients as it offers an adjustable treatment option 1
• Target: ventral intermediate nucleus (VIM) of the thalamus 1
• Requires inpatient admission for careful post-operative monitoring 1
• Awake procedure allows for intraoperative testing to confirm optimal electrode placement 1

Radiofrequency thalamotomy: Reserve for cases where MRgFUS and DBS are not feasible 1

• Higher complication risk (11.8%) than MRgFUS 1

Patient Eligibility Criteria for Surgery

• Confirmed diagnosis of essential tremor 1
• Failed treatment with first-line medications 1
• Tremor significantly affecting activities of daily living 1
• No dementia or severe depression 1
• Sufficient residual motor function to expect improvement 1
• No cerebral atrophy or focal lesions of the basal ganglia on MRI 1

Monitoring and Follow-up

• Regular assessment of tremor severity and medication side effects is essential 1
• Dose adjustments may be needed based on clinical response and tolerability 1
• If first-line agents fail, consider switching to or adding second-line medications before considering surgical options 1