How is essential tremor typically managed?

Management of Essential Tremor

Initiate treatment with either propranolol (80-240 mg/day) or primidone as first-line therapy when tremor interferes with function or quality of life, as both demonstrate efficacy in up to 70% of patients. 1, 2

First-Line Pharmacological Treatment

Propranolol and primidone are equally effective first-line options recommended by the American Academy of Neurology. 1, 2

• Propranolol is the most established medication, used for over 40 years with demonstrated efficacy at doses of 80-240 mg/day 1, 2

  • Avoid in patients with COPD, bradycardia, or congestive heart failure 1, 2
  • Common adverse effects include fatigue, depression, dizziness, hypotension, cold extremities, and bronchospasm 1
  • May provide dual benefits in patients with both essential tremor and hypertension 1

• Primidone is an equally effective alternative 1, 2

  • Clinical benefits may not appear for 2-3 months, requiring an adequate trial period 1, 2
  • Therapeutic benefit can occur even when derived phenobarbital levels remain subtherapeutic 1, 2
  • Women of childbearing age require counseling about teratogenic risks (neural tube defects) 1, 2
  • Side effects include behavioral disturbances, irritability, and sleep disturbances at higher doses 1

Second-Line Pharmacological Options

If first-line agents fail or are not tolerated, consider these alternatives:

• Alternative beta-blockers: Nadolol (40-320 mg daily), metoprolol (25-100 mg), atenolol, or timolol (20-30 mg/day) 1
• Topiramate as a second-line agent 3, 4
• Gabapentin has limited evidence for moderate efficacy 1, 4
• Carbamazepine may be used as second-line therapy, though generally less effective than first-line options 1

Combination Therapy

• If monotherapy with propranolol or primidone provides inadequate control, use both medications in combination 5
• Nearly half of patients (46.6%) receive monotherapy, while 18.2% require two medications 6

Surgical Interventions for Refractory Cases

Consider surgical options when medications fail due to lack of efficacy at maximum doses, dose-limiting side effects, or medical contraindications. 1, 2

Magnetic Resonance-Guided Focused Ultrasound (MRgFUS) Thalamotomy

• Preferred for unilateral tremor, showing sustained tremor improvement of 56% at 4 years 1, 2, 7
• Lowest complication rate (4.4%) compared to radiofrequency thalamotomy (11.8%) and DBS (21.1%) 1, 7
• Early adverse effects include gait disturbance (36%) and paresthesias (38%), decreasing to 9% and 14% respectively by 1 year 1
• Serious adverse events are rare (1.6%), with most being mild or moderate (98.4%) 1

Contraindications for MRgFUS:

• Inability to undergo MRI 1, 7
• Skull density ratio <0.40 1, 7
• Bilateral treatment needs 1, 7
• Contralateral to previous thalamotomy 1, 7

Deep Brain Stimulation (DBS)

• Preferred for bilateral tremor or patients with contraindications to MRgFUS 1
• Provides adjustable, reversible tremor control that can be optimized over time 1
• Targets the ventral intermediate nucleus (VIM) of the thalamus 1
• Approximately 90% tremor control rate 5
• Requires inpatient admission for careful post-operative monitoring 1

Radiofrequency Thalamotomy

• Available but carries higher complication risks (11.8%) than MRgFUS 1, 7
• Only considered when DBS or MRgFUS are not possible 3

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 1
• Use gross rather than fine movements, especially for handwriting 1
• Avoid cocontraction or tensing of muscles 1
• Treadmill training with partial body weight support for patients with gait dysfunction 2

Treatment Algorithm

1. Assess functional impact: Only initiate treatment when tremor interferes with function or quality of life 1, 2
2. Start first-line therapy: Propranolol or primidone 1, 2
3. If inadequate response: Switch to alternative first-line agent or combine both 1
4. If still inadequate: Add second-line medications (topiramate, gabapentin, alternative beta-blockers) 1
5. If medication-refractory: Consider surgical options based on tremor laterality and patient characteristics 1, 2
   • Unilateral tremor → MRgFUS thalamotomy 1, 2
   • Bilateral tremor → DBS 1

Monitoring and Follow-Up

• Regular assessment of tremor severity and medication side effects is essential 1, 2
• Dose adjustments based on clinical response and tolerability 1, 2
• Recognize that current medications improve tremor in only approximately 50% of patients 5, 4
• In real-world practice, 27.1% of patients receive no treatment, and 13.4% of prescriptions are discontinued due to side effects 6