What is the workup for a patient presenting with whole body tremors?

Diagnostic Workup for Whole Body Tremors

The diagnostic workup for whole body tremors should begin with a detailed tremor assessment including observation at rest, with sustained posture, and during movement, followed by targeted laboratory testing to rule out secondary causes, and appropriate neuroimaging when indicated. 1

Initial Tremor Assessment

History Taking

• Activation conditions: Determine if tremor occurs at:

  • Rest (4-6 Hz): When body part is relaxed and supported
  • Postural (4-8 Hz): When maintaining position against gravity
  • Kinetic: During voluntary movement
  • Isometric: During muscle contraction against stationary object 1, 2

• Triggers and modifying factors:

  • Emotional stress, anxiety, fatigue
  • Caffeine intake or medication use
  • Pain or physical exertion
  • Relationship to standing position 3

• Associated symptoms:

  • Nausea, sweating, pallor before episodes
  • Loss of consciousness or postural tone
  • Recovery pattern and post-episode fatigue 3

Physical Examination

• Tremor characteristics:

  • Frequency (4-12 Hz for essential tremor)
  • Amplitude
  • Symmetry vs. asymmetry (asymmetric tremor suggests Parkinson's disease)
  • Distribution (arms, head, voice, legs, whole body) 1, 2

• Neurological assessment:

  • Test for bradykinesia, rigidity, and cerebellar signs
  • Assess for re-emergent tremor (characteristic of Parkinson's)
  • Look for dystonic posturing
  • Evaluate for extinction with distraction (suggests psychogenic tremor) 1, 4

Laboratory Testing

• Basic metabolic workup:

  • Complete blood count
  • Comprehensive metabolic panel
  • Thyroid function tests (TSH, free T4)
  • Liver function tests
  • HbA1c 1

• Additional tests based on clinical suspicion:

  • Copper studies and ceruloplasmin if Wilson's disease suspected
  • Heavy metal screening if exposure history
  • Drug and toxicology screen
  • Calcium, magnesium, phosphate levels 1, 5

Neuroimaging

• Brain MRI: Indicated when:

  • Tremor has acute onset
  • Tremor is accompanied by other neurological symptoms
  • Asymmetric or unilateral tremor
  • Rapid progression
  • Red flag symptoms (headache, focal deficits) 1

• Advanced imaging techniques for normal MRI findings:

  • Diffusion tensor imaging
  • Susceptibility-weighted imaging 1

• Functional neuroimaging for diagnostic uncertainty:

  • Single-photon emission computed tomography (SPECT) to visualize dopaminergic pathways (helpful in differentiating Parkinson's disease from essential tremor)
  • Transcranial ultrasonography for Parkinson's disease 2, 4

Specialized Testing

• Electrophysiological studies:

  • Surface electromyography to determine tremor frequency and pattern
  • Accelerometry for objective tremor quantification 5

• Tilt table testing:

  • Consider if syncope or orthostatic tremor is suspected
  • Monitors blood pressure and heart rate during provoked episodes 3

Differential Diagnosis Considerations

Common Causes of Whole Body Tremors

1. Enhanced physiological tremor: Exacerbated by anxiety, medications, caffeine, fatigue
2. Essential tremor: Most common pathologic tremor (0.4-6% of population)
3. Parkinsonian tremor: Typically unilateral, resting tremor that diminishes with movement
4. Drug-induced tremor: Beta-agonists, stimulants, lithium, valproate, antipsychotics
5. Metabolic tremor: Hyperthyroidism, hypoglycemia, electrolyte disturbances
6. Psychogenic tremor: Abrupt onset, changing characteristics, extinction with distraction 2, 4, 6

Common Pitfalls to Avoid

• Misdiagnosing dystonic tremor as essential tremor
• Overlooking drug-induced causes
• Failing to recognize psychogenic tremor
• Not considering orthostatic tremor in patients with tremor primarily when standing
• Confusing syncope with tremor disorders 1

By following this systematic approach to tremor evaluation, clinicians can effectively diagnose the underlying cause of whole body tremors and develop appropriate treatment strategies to improve patient outcomes and quality of life.