What laboratory tests are recommended for a patient with an idiopathic Cerebrovascular Accident (CVA)?

Laboratory Tests for Idiopathic Cerebrovascular Accident (CVA)

For patients with idiopathic CVA, a comprehensive laboratory workup should include complete blood count, coagulation studies, metabolic panel, lipid profile, inflammatory markers, cardiac biomarkers, and specialized testing for hypercoagulable states to identify potential underlying causes and guide secondary prevention strategies. 1

Core Laboratory Tests

Essential Initial Blood Work

• Complete blood count (CBC) - to identify anemia, thrombocytopenia, or leukocytosis 1
• Coagulation studies:
  • Prothrombin time (PT) with INR
  • Activated partial thromboplastin time (aPTT) 1
• Metabolic panel:
  • Electrolytes
  • Blood urea nitrogen and creatinine (renal function)
  • Estimated glomerular filtration rate (eGFR)
  • Liver function tests 1
• Glucose and HbA1c - to identify diabetes or impaired glucose tolerance 1
• Lipid profile - fasting or non-fasting 1
• Inflammatory markers - ESR and/or CRP 1
• Cardiac biomarkers - troponin 1
• Toxicology screen - particularly for younger patients 1, 2

Cardiac Evaluation

• 12-lead ECG - to screen for atrial fibrillation and other cardiac conditions 1
• Extended cardiac monitoring - for at least 24 hours, ideally 14+ days in cryptogenic stroke to detect paroxysmal atrial fibrillation 1

Additional Testing for Cryptogenic Stroke

When initial evaluation doesn't reveal a clear etiology, additional testing should be considered:

Hypercoagulable Testing

• Inherited thrombophilia markers:
  • Factor V Leiden
  • Prothrombin gene mutation
  • Protein C, Protein S, and Antithrombin III levels 1
• Acquired hypercoagulable states:
  • Antiphospholipid antibodies
  • Lupus anticoagulant
  • Anticardiolipin antibodies
  • Beta-2 glycoprotein antibodies 1

Infectious and Inflammatory Workup

• Infectious disease screening:
  • HIV
  • Syphilis (RPR/VDRL)
  • Hepatitis panel 1
• Autoimmune markers:
  • ANA
  • ANCA
  • Complement levels 1

Clinical Pearls and Pitfalls

Important Considerations

• Laboratory testing should be completed within 48 hours of stroke onset to optimize secondary prevention strategies 1
• D-dimer testing may be helpful when cerebral venous thrombosis is suspected, though a normal result doesn't exclude the diagnosis if clinical suspicion is high 1
• Specialized testing for rare causes should be guided by clinical suspicion rather than performed routinely on all patients 1

Common Pitfalls

1. Delayed workup - Completing diagnostic evaluation promptly (within 48 hours) is essential for optimal secondary prevention 1
2. Overlooking cardiac sources - Atrial fibrillation may be paroxysmal and require extended monitoring beyond the initial ECG 1
3. Incomplete vascular assessment - Laboratory tests should complement, not replace, appropriate vascular imaging 1
4. Missing medication-related causes - Comprehensive medication review should accompany laboratory testing 1
5. Failing to assess for substance use - Toxicology screening is particularly important in younger patients with cryptogenic stroke 1, 2

Special Populations

• Young patients (<50 years) - More extensive hypercoagulable and autoimmune workup is warranted 1
• Patients with recurrent stroke - Consider rare genetic disorders and specialized testing 1
• Patients with family history of thrombosis - More extensive thrombophilia testing is indicated 1

The laboratory evaluation should be performed in conjunction with appropriate neuroimaging and vascular studies to establish etiology and guide secondary prevention strategies.