What is the initial workup and treatment approach for a patient presenting with tremors?

Workup of Tremors

Initial Clinical Assessment

Begin by categorizing the tremor based on its activation condition (rest vs. action), topographic distribution, and frequency—this classification drives the entire diagnostic and therapeutic approach. 1, 2, 3

Key History Elements

• Activation condition: Determine if tremor occurs at rest (body part relaxed and supported against gravity) or with action (voluntary muscle contraction) 2, 3, 4
• Temporal pattern: Document onset (abrupt vs. gradual), duration, progression, and whether symptoms are intermittent or constant 1, 2
• Exacerbating factors: Specifically ask about anxiety, caffeine, strenuous exercise, fatigue, alcohol use, and specific activities like writing or eating 1, 2
• Medication review: Screen for tremor-inducing drugs including sympathomimetics, lithium, valproate, antipsychotics, antidepressants, and antiparkinsonians 1, 2
• Functional impact: Quantify interference with writing, eating, drinking, dressing, and other activities of daily living 1, 2
• Family history: Essential tremor has autosomal dominant inheritance in 50% of cases 2, 3
• Associated symptoms: Ask about bradykinesia, rigidity, postural instability, gait disturbance, ataxia, dystonia, or psychiatric symptoms 5, 2, 4

Physical Examination Findings

• Tremor characteristics: Observe frequency (low <4 Hz suggests parkinsonian; high 4-12 Hz suggests essential or physiologic), amplitude, and symmetry 2, 3, 4
• Body distribution: Note if tremor affects hands (unilateral vs. bilateral), head, voice, legs, or trunk 2, 4, 6
• Parkinsonian features: Assess for masked facies, reduced arm swing, cogwheel rigidity, bradykinesia, and postural instability 2, 3
• Cerebellar signs: Test for ataxia, dysmetria, intention tremor, and abnormal eye movements 5, 2, 4
• Dystonic posturing: Look for abnormal sustained postures, particularly in the neck or limbs 4, 6
• Psychogenic features: Test for distractibility (tremor diminishes with cognitive tasks), entrainment (tremor frequency changes when patient taps at different rate with opposite hand), and variability in tremor characteristics 2, 3, 4

Diagnostic Testing

Laboratory Evaluation

• Thyroid function tests: Hyperthyroidism causes enhanced physiologic tremor 5, 2
• Complete blood count: Screen for anemia as a precipitating factor 5
• Comprehensive metabolic panel: Evaluate for electrolyte disturbances, renal failure, and hepatic dysfunction 2
• Serum ceruloplasmin and 24-hour urine copper: Consider in patients under age 40 to exclude Wilson disease 2, 4

Neuroimaging

• Brain MRI: Obtain when tremor is accompanied by other neurologic signs (ataxia, weakness, sensory changes), rapid progression, or age of onset under 40 years 2, 4
• DaTscan (SPECT imaging): Use when diagnostic uncertainty exists between essential tremor and Parkinson disease—shows reduced dopamine transporter uptake in Parkinson disease but normal uptake in essential tremor 2, 3, 7

Treatment Approach by Tremor Type

Essential Tremor (Bilateral Action Tremor)

Propranolol 80-240 mg/day or primidone starting at 25 mg at bedtime are first-line treatments when tremor interferes with function or quality of life. 1

• Propranolol: Effective in up to 70% of patients; contraindicated in chronic obstructive pulmonary disease, bradycardia, or congestive heart failure 1
• Primidone: Start at 25 mg at bedtime, increase gradually to 250 mg three times daily; requires 2-3 month trial to assess therapeutic benefit 1
• Second-line options: Gabapentin, topiramate, or botulinum toxin injections for head/voice tremor 6, 7

Parkinsonian Tremor (Unilateral Rest Tremor)

• Dopaminergic therapy: Levodopa/carbidopa is first-line for Parkinson disease with tremor 8, 9
• Dopamine agonists: Pramipexole or ropinirole can be used as monotherapy in early disease or as adjunct to levodopa in advanced disease 8, 9

Enhanced Physiologic Tremor

• Address underlying cause: Discontinue offending medications, reduce caffeine intake, treat hyperthyroidism, correct electrolyte abnormalities 2, 3
• Beta-blockers: Propranolol 10-40 mg as needed before anxiety-provoking situations 2

Cerebellar Tremor

• Treat underlying cause: Address structural lesions, multiple sclerosis, or alcohol-related cerebellar degeneration 4, 7
• Symptomatic treatment: Clonazepam or propranolol may provide modest benefit 7

Surgical Interventions for Refractory Cases

MRI-guided focused ultrasound (MRgFUS) thalamotomy is preferred for medically refractory unilateral essential tremor, with a complication rate of 4.4% at one year. 5, 1

• MRgFUS indications: Unilateral tremor (dominant or non-dominant hand), medical comorbidities precluding open surgery, patient preference for non-invasive approach 5, 1
• MRgFUS contraindications: Skull density ratio <0.40, MRI contraindications, need for bilateral treatment, previous contralateral thalamotomy 5
• Deep brain stimulation (DBS): Consider for bilateral tremor involvement or when MRgFUS is contraindicated; complication rate 21.1% 5, 1

Common Pitfalls to Avoid

• Premature equipment provision: Avoid prescribing adaptive devices or aids in the acute phase, as they reinforce maladaptive movement patterns and prevent recovery 5, 1
• Inadequate primidone trial: Do not discontinue primidone before 2-3 months, as therapeutic benefit may be delayed 1
• Beta-blocker complications: Always screen for contraindications (COPD, bradycardia, heart failure) before prescribing propranolol 1
• Misdiagnosis of psychogenic tremor: Establish positive clinical signs (distractibility, entrainment, variability) rather than treating as diagnosis of exclusion 2, 3, 4
• Treating tremor presence rather than functional impact: Only initiate treatment when tremor interferes with quality of life or daily function 1, 2