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

Workup for Tremors

Begin by determining whether the tremor occurs at rest or with action, as this single distinction drives the entire diagnostic and treatment algorithm. 1

Initial Clinical Characterization

The first step is to classify the tremor based on its activation pattern:

• Resting tremor (4-6 Hz) that improves with movement suggests Parkinsonian tremor and requires urgent evaluation for Parkinson's disease or secondary parkinsonism 2
• Action tremor (postural/kinetic, 4-8 Hz) that occurs with voluntary movement suggests essential tremor 1, 2
• Intention tremor that worsens as the limb approaches a target indicates cerebellar pathology 1
• Highly variable tremor that stops completely with distraction is the hallmark of functional (psychogenic) tremor 2

Document the tremor's topographic distribution (unilateral vs bilateral, which body parts), frequency, and factors that worsen or improve it (alcohol, stress, caffeine) 1, 2.

Critical Life-Threatening Causes to Rule Out First

In Young Patients (Age <40)

Wilson's disease is the critical diagnosis not to miss, as it is treatable and can present with tremor, dystonia, and parkinsonian features 2:

• Check serum ceruloplasmin and 24-hour urinary copper 2
• Perform slit-lamp examination for Kayser-Fleischer rings 2
• Look for drooling and oropharyngeal dystonia, which are characteristic manifestations 2

Medication and Metabolic Causes (All Ages)

• Review all medications for tremor-inducing drugs: lithium, valproate, calcium channel blockers, beta-agonists, SSRIs, antipsychotics 1
• Screen for metabolic disturbances: thyroid function tests (hyperthyroidism), glucose (hypoglycemia), electrolytes 1
• Assess for substance use: caffeine (extremely common), alcohol withdrawal, stimulants 2, 3
• Consider serotonin syndrome in patients on multiple serotonergic medications (characterized by tremor with hyperreflexia, clonus, autonomic instability) 2

Focused Neurological Examination

For Suspected Parkinsonian Tremor

• Assess for bradykinesia (slowness of movement), rigidity (cogwheel or lead-pipe), and postural instability 2
• Evaluate gait pattern for shuffling, festination, or freezing 2
• Look for red flags for atypical parkinsonism: early prominent falls, rapid progression, poor levodopa response, early autonomic dysfunction, vertical gaze palsy 2

For Suspected Essential Tremor

• Confirm bilateral upper limb action tremor that is progressive 1
• Check for response to alcohol (improves tremor in many cases) 1
• Ensure no other neurologic signs are present (bradykinesia, dystonia, ataxia) 1

For Suspected Cerebellar Tremor

• Look for associated ataxia and dysarthria 1
• Observe for coarse and irregular "wing-beating" appearance 1

Diagnostic Testing

Neuroimaging

MRI brain without contrast is the optimal imaging modality to evaluate for structural causes, parkinsonian syndromes, cerebellar pathology, and Wilson disease 2.

Specialized Testing (When Diagnostic Uncertainty Exists)

• DaTscan (Ioflupane) SPECT imaging can differentiate parkinsonian syndromes from essential tremor and drug-induced tremor; a normal scan essentially excludes parkinsonian syndromes 2, 3
• Electromyography (EMG) can help characterize tremor frequency and pattern when clinical examination is inconclusive 4

Therapeutic Trial

• A levodopa/carbidopa trial can help differentiate Parkinson's disease (which responds) from atypical parkinsonism (which does not respond well) 2, 5

Functional Impact Assessment

Evaluate the functional impact on daily activities such as writing, eating, and drinking to determine the need for treatment 1. Treatment is only initiated when tremor symptoms interfere with function or quality of life 1, 6.

Common Pitfalls to Avoid

• Do not assume all tremors in young patients are benign essential tremor—Wilson's disease must be excluded 2
• Do not overlook medication and substance-induced tremor, including caffeine, which is extremely common 2
• Do not confuse akathisia with tremor—akathisia is severe restlessness from antipsychotics manifesting as pacing 2
• Do not diagnose essential tremor if isolated head/voice tremor or task-specific tremor is present 7

Treatment Algorithm (Once Diagnosis Established)

For Essential Tremor

Propranolol (80-240 mg/day) or primidone are first-line therapies when tremor interferes with function or quality of life, with response rates up to 70% 1, 6:

• Propranolol is contraindicated in chronic obstructive pulmonary disease, bradycardia, or congestive heart failure 6
• Primidone may cause behavioral disturbances and sleep disturbances; clinical benefits may not appear for 2-3 months 6
• For medication-refractory tremor, consider MRgFUS thalamotomy (56% sustained improvement at 4 years, 4.4% complication rate) or deep brain stimulation (21.1% complication rate but adjustable) 1, 6

For Parkinsonian Tremor

• Levodopa/carbidopa is the primary treatment for Parkinson's disease tremor 5
• Dopamine agonists like ropinirole may also be effective 8