What is the treatment for tremors in a patient with Parkinson’s disease?

Treatment of Tremors in Parkinson's Disease

Levodopa/carbidopa is the first-line treatment for tremors in Parkinson's disease patients, as it is the most effective medication for treating motor symptoms including tremor. 1, 2

First-Line Pharmacological Treatment

• Levodopa, the metabolic precursor of dopamine, crosses the blood-brain barrier and is converted to dopamine in the brain, which is the primary mechanism for relieving Parkinson's disease symptoms including tremor 2
• Carbidopa inhibits peripheral decarboxylation of levodopa, making more levodopa available for transport to the brain while reducing side effects 3
• For optimal absorption, levodopa should be taken at least 30 minutes before meals to avoid interactions with dietary proteins that can reduce efficacy 1

Second-Line and Adjunctive Treatments

• Dopamine agonists (e.g., pramipexole) can be added to levodopa therapy or used as monotherapy in early disease to reduce tremor 4, 5
• Anticholinergic medications may be particularly effective for tremor control, especially in tremor-dominant Parkinson's disease 6
• For patients with medication-resistant tremor, consider adding amantadine, clonazepam, or propranolol as adjunctive therapy 6

Advanced Therapies for Medication-Resistant Tremor

• Deep brain stimulation (DBS) is the most well-established advanced therapy for medication-resistant tremor due to its long-term efficacy and reversibility 5, 7
• When considering DBS target selection:
  • Both subthalamic nucleus (STN) and globus pallidus internus (GPi) DBS are effective for motor symptom control including tremor 8
  • If medication reduction is a primary goal, STN DBS is preferred 8
  • If there are concerns about cognitive decline or depression, GPi DBS may be more appropriate 8
• Magnetic resonance-guided focused ultrasound (MRgFUS) is an emerging incisionless option for medication-resistant tremor that doesn't require surgical implantation 8, 5
• Botulinum toxin injections can be effective for patients with pharmacological-resistant tremor who are not candidates for advanced therapies 5

Important Considerations for Treatment

• Tremor in Parkinson's disease may be less responsive to dopaminergic therapy than other motor symptoms, particularly in tremor-dominant PD 5, 6
• Protein redistribution diets (consuming most protein later in the day) can improve motor function in patients experiencing motor fluctuations on levodopa 1
• Monitor for common side effects of levodopa including nausea, vomiting, abdominal pain, and hyperhomocysteinemia, especially in older patients 1

Common Pitfalls and Caveats

• Avoid strict low-protein diets as they may lead to nutritional deficiencies without evidence-based benefits 1
• Increasing doses of levodopa over time are associated with a higher risk for malnutrition, requiring careful monitoring 1
• Differential diagnosis between Parkinson's disease tremor and essential tremor is crucial as treatment approaches differ significantly 9
• Some patients may develop both resting tremor (characteristic of PD) and postural/kinetic tremor components, which may require combination therapy 9