What is the treatment for essential tremor?

Treatment of Essential Tremor

Start with propranolol (80-240 mg/day) or primidone as first-line therapy, as these medications are effective in up to 70% of patients with essential tremor. 1

First-Line Pharmacological Treatment

The American Academy of Neurology recommends two equally effective first-line options 1:

• Propranolol (80-240 mg/day) is the most established medication, used for over 40 years with demonstrated efficacy 2, 1
• Primidone is the alternative first-line agent, though clinical benefits may not appear for 2-3 months, requiring an adequate trial period 1

Only initiate medication when tremor interferes with function or quality of life 1, 3

Important Propranolol Contraindications and Precautions

Beta-blockers must be avoided in specific populations 1, 3:

• Patients with chronic obstructive pulmonary disease (risk of bronchospasm) 1
• Patients with bradycardia 1
• Patients with congestive heart failure 1
• Elderly patients are at higher risk for excessive heart rate reduction leading to serious adverse events 1

Common adverse effects include fatigue, depression, dizziness, hypotension, exercise intolerance, sleep disorders, and cold extremities 1

Primidone Considerations

• Therapeutic benefit occurs even when phenobarbital levels remain subtherapeutic, confirming primidone itself has anti-tremor properties 1
• Side effects include behavioral disturbances, irritability, and sleep disturbances at higher doses 1
• Women of childbearing age require counseling about teratogenic risks (neural tube defects) 1

Second-Line Pharmacological Options

If propranolol or primidone fail individually, combine both medications before moving to other agents 4

Alternative beta-blockers if propranolol causes adverse effects 1, 4:

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

Other second-line medications 1, 4:

• Gabapentin (limited evidence for moderate efficacy) 1
• Topiramate 5, 6
• Benzodiazepines (particularly for tremor associated with anxiety or stress-induced exacerbations) 4, 6

Surgical Interventions for Medication-Refractory Tremor

Consider surgical options 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:

• Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy is preferred due to sustained tremor improvement of 56% at 4 years and the lowest complication rate (4.4%) compared to radiofrequency thalamotomy (11.8%) and DBS (21.1%) 1, 7, 3

For bilateral tremor:

• Deep brain stimulation (DBS) is the procedure of choice, as MRgFUS is contraindicated bilaterally 1, 3
• DBS provides adjustable, reversible tremor control that can be optimized over time 1
• DBS targeting the ventral intermediate nucleus (VIM) of the thalamus provides adequate tremor control in approximately 90% of patients 1, 4

MRgFUS Contraindications

MRgFUS cannot be used in 1, 3:

• Patients unable to undergo MRI 1
• Patients with skull density ratio <0.40 1
• Bilateral treatment needs 1
• Contralateral to a previous thalamotomy 1

MRgFUS Adverse Effects

Early adverse effects are common but typically resolve 1:

• Gait disturbance (36% initially, decreasing to 9% by 1 year) 1
• Paresthesias (38% initially, decreasing to 14% 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

Special Clinical Scenarios

For patients with both essential tremor and hypertension:

• Beta-blockers provide dual therapeutic benefits 1, 3

For stress or anxiety-induced tremor exacerbations:

• Propranolol or benzodiazepines can be used as needed during periods when tremor causes functional disability 4

For head or voice tremor:

• Botulinum toxin injections into affected muscles may provide relief 4, 8
• Hand tremor treatment with botulinum toxin can cause bothersome weakness and is not widely used 4

Common Pitfalls to Avoid

• Do not use epinephrine to treat propranolol overdose, as it can cause uncontrolled hypertension due to unopposed alpha-receptor stimulation 9
• Monitor prothrombin time when propranolol is administered with warfarin, as propranolol increases warfarin concentration 9
• Avoid NSAIDs when possible, as they may blunt the antihypertensive and heart rate-reducing effects of propranolol 9
• Do not dismiss primidone as ineffective before allowing 2-3 months for clinical benefits to appear 1