What is the appropriate workup for a patient presenting with tremors?

Comprehensive Approach to Tremor Evaluation

The appropriate workup for a patient presenting with tremors should include a detailed characterization of the tremor type, focused neurological examination, relevant laboratory tests, and targeted imaging based on clinical suspicion.

Initial Tremor Assessment

Tremor Classification

• Rest tremor: Occurs when body part is completely supported against gravity (e.g., hands resting on lap)

  • Most commonly associated with Parkinson's disease 1
  • Typically 4-6 Hz frequency 2
  • Improves with voluntary movement

• Action tremors: Occur during voluntary muscle contraction

  • Postural tremor: Present when maintaining a position against gravity
  • Kinetic tremor: Occurs during voluntary movement
  • Intention tremor: Worsens as approaching a target, often with cerebellar signs 1

Key History Elements

• Age of onset and progression pattern
• Affected body parts (hands, head, voice, legs)
• Aggravating and alleviating factors
• Family history of tremor or neurological disorders
• Associated neurological symptoms (bradykinesia, rigidity, balance problems)
• Medication history (including over-the-counter medications)
• Alcohol or caffeine consumption
• Impact on activities of daily living

Physical Examination

• Neurological examination with special attention to:

  • Tremor characteristics during different positions and activities
  • Presence of bradykinesia, rigidity, or other parkinsonian signs
  • Cerebellar function (coordination, gait, dysmetria)
  • Muscle tone and strength
  • Reflexes and sensory function

• Specific tremor tests:

  • Observe tremor at rest, with arms outstretched, during finger-to-nose testing
  • Assess writing and drawing (spiral test)
  • Evaluate for distractibility (suggests psychogenic tremor)
  • Perform "get up and go test" for balance assessment 3

Laboratory Investigations

First-line Laboratory Tests

• Complete blood count
• Comprehensive metabolic panel
• Thyroid function tests (TSH, free T4)
• Liver function tests
• Serum glucose
• Calcium and phosphorus levels 1

Second-line Laboratory Tests (Based on Clinical Suspicion)

• Serum ceruloplasmin and 24-hour urinary copper (for Wilson's disease)
• Heavy metal screening if exposure suspected
• Drug levels if medication-induced tremor suspected
• Vitamin B12 and folate levels

Imaging Studies

Brain Imaging

• MRI brain: Preferred modality for evaluating structures involved in movement disorders 1

  • Indicated for:
    • Asymmetric or unilateral tremor
    • Acute or subacute onset
    • Associated neurological signs
    • Tremor not consistent with common etiologies
  • Can identify structural lesions in basal ganglia, cerebellum, or brainstem

• DaTscan (123I-ioflupane SPECT): May help differentiate essential tremor from parkinsonic tremors when clinical diagnosis is uncertain

Special Considerations

Age-Specific Approach

• Young patients (<40 years):

  • Consider Wilson's disease (especially with liver dysfunction)
  • Drug-induced tremors
  • Hereditary causes

• Older patients:

  • Essential tremor and Parkinson's disease more common
  • Medication side effects
  • Multiple system atrophy and progressive supranuclear palsy 1

Red Flags Requiring Urgent Evaluation

• Acute onset tremor
• Rapidly progressive symptoms
• Associated focal neurological deficits
• Signs of increased intracranial pressure
• Altered mental status 3

Common Tremor Etiologies and Specific Workup

Essential Tremor

• Most common tremor disorder 2
• Typically postural and kinetic tremor (4-8 Hz)
• Often involves upper extremities and head
• Family history in approximately 50% of cases
• May improve temporarily with alcohol consumption

Parkinsonian Tremor

• Classic 4-6 Hz rest tremor
• Associated with bradykinesia, rigidity, and postural instability
• Asymmetric onset
• "Pill-rolling" quality of hand tremor

Physiologic and Enhanced Physiologic Tremor

• Exacerbated by anxiety, caffeine, medications, hyperthyroidism
• Fine, fast (8-12 Hz) postural tremor
• Check thyroid function, medications, and metabolic status

Cerebellar Tremor

• Intention tremor that worsens approaching target
• Associated with dysmetria, dysdiadochokinesia
• Brain imaging (MRI) to evaluate for cerebellar pathology

Drug-Induced Tremor

• Comprehensive medication review essential
• Common culprits: antipsychotics, SSRIs, lithium, valproate, bronchodilators, stimulants

Metabolic Tremor

• Check for hyperthyroidism, hypoglycemia, electrolyte disturbances
• Evaluate liver and renal function

By systematically evaluating tremor characteristics and following this diagnostic algorithm, clinicians can efficiently determine the underlying cause and develop an appropriate treatment plan for patients presenting with tremors.