What is the treatment for essential tremor?

Treatment of Essential Tremor

First-Line Pharmacological Treatment

Start with either propranolol (80-240 mg/day) or primidone as first-line therapy for essential tremor—both are equally effective in up to 70% of patients. 1

Propranolol

• Propranolol is the most established medication for essential tremor, with over 40 years of demonstrated efficacy. 1
• Dosing: 80-240 mg/day, titrated to effect 1, 2
• Provides dual benefit in patients with concurrent hypertension 1
• Contraindications include: 1, 2
  • Chronic obstructive pulmonary disease
  • Bradycardia
  • Congestive heart failure
• 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 as propranolol as first-line therapy 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 should be counseled about teratogenic risks (neural tube defects) 1

When to Initiate Treatment

• Medications are only initiated when tremor symptoms interfere with function or quality of life 1

Second-Line Pharmacological Options

If first-line agents fail or are not tolerated, consider these alternatives before surgical options: 1

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: limited evidence for moderate efficacy 1
• Topiramate: considered a second-line option 3, 4
• Carbamazepine: may be used as second-line therapy, though generally not as effective as first-line therapies 1

Combination Therapy

• If monotherapy with propranolol or primidone provides inadequate control, these medications can be used in combination 5

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
• Avoid cocontraction or tensing of muscles as this is unlikely to be a helpful long-term strategy 1

Important Pitfall

• Avoid prescribing aids and equipment for tremor 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 Options for Medication-Refractory Tremor

Surgical therapies should be considered 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: MRgFUS thalamotomy is preferred 1

For bilateral tremor: Deep brain stimulation (DBS) is the procedure of choice 1

Magnetic Resonance-Guided Focused Ultrasound (MRgFUS) Thalamotomy

• Shows sustained tremor improvement of 56% at 4 years 1
• Lowest complication rate (4.4%) compared to radiofrequency thalamotomy (11.8%) and DBS (21.1%) 1
• 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: 1
  • Cannot undergo MRI
  • Skull density ratio <0.40
  • Bilateral treatment needed
  • Contralateral to a previous thalamotomy

Deep Brain Stimulation (DBS)

• Provides adjustable, reversible tremor control that can be optimized over time 1
• Target: ventral intermediate nucleus (VIM) of the thalamus 1
• Preferred for relatively young patients as it offers an adjustable treatment option 1
• Preferred for bilateral tremor involvement 1
• Complication rate: 21.1% 1
• Patient eligibility requires: 1
  • No dementia or severe depression
  • Sufficient residual motor function to expect improvement
  • No cerebral atrophy or focal lesions of the basal ganglia on MRI
  • Failed first-line medication therapy

Radiofrequency Thalamotomy

• Available but carries higher complication risks (11.8%) than MRgFUS 1
• Only rarely performed if DBS or focused ultrasound is not possible 3

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