What are the recommended diagnostic tests and labs for a Cerebrovascular Accident (CVA) workup, beyond noncontrast Computed Tomography (CT) head and Computed Tomography Angiography (CTA) head and neck?

Comprehensive Diagnostic Workup for Cerebrovascular Accident (CVA)

Beyond noncontrast CT head and CTA head and neck, a comprehensive CVA workup should include MRI brain without and with contrast, MRA head and neck, laboratory tests including CBC, coagulation studies, lipid panel, HbA1c, and cardiac evaluation with ECG and echocardiography. 1

Initial Laboratory Evaluation

• Complete Blood Count (CBC)

  • Evaluates for anemia, polycythemia, thrombocytopenia, or thrombocytosis that may contribute to stroke risk
  • Elevated white blood cell count may indicate infection as a stroke trigger

• Coagulation Studies

  • PT/INR, aPTT, and fibrinogen to assess clotting function
  • D-dimer if venous sinus thrombosis is suspected

• Basic Metabolic Panel

  • Electrolytes, glucose, renal function
  • Hyponatremia or hyperglycemia can mimic stroke symptoms

• Cardiac Biomarkers

  • Troponin to rule out concurrent myocardial infarction

• Lipid Panel

  • Total cholesterol, LDL, HDL, triglycerides
  • Important for secondary prevention planning

• HbA1c

  • Identifies undiagnosed diabetes or poor glycemic control

• Additional Tests Based on Clinical Suspicion

  • ESR and CRP if vasculitis is suspected
  • Homocysteine levels
  • Hypercoagulability workup in young patients (protein C, protein S, antithrombin III, factor V Leiden, antiphospholipid antibodies)

Advanced Imaging

MRI Brain

• MRI without and with contrast (Rating: 8/9) 1
  • Superior to CT for detecting acute, subacute, and chronic infarcts
  • Helps determine infarct age and evaluate for alternative diagnoses
  • Particularly valuable for posterior fossa strokes which may be missed on CT
  • DWI sequence critical for detecting early ischemic changes

Vascular Imaging

• MRA head and neck without and with IV contrast (Rating: 8/9) 1

  • Evaluates intracranial and extracranial vessels for stenosis, occlusion, or dissection
  • Noncontrast MRA for head vessels and contrast-enhanced MRA for neck vessels is the preferred approach
  • Useful for follow-up after initial CTA

• CT Venography (CTV) head with IV contrast 1

  • Essential when cerebral venous thrombosis is suspected
  • Particularly indicated when:
    • Infarcts don't match arterial territories
    • Parasagittal or temporoparietal location
    • Cortical sparing
    • Presence of dural venous/cortical venous hyperdensity

• Perfusion Imaging

  • CT or MRI perfusion (Rating: 5-6/9) 1
  • Helps identify penumbra (salvageable tissue) in acute stroke
  • Useful for selecting candidates for extended-window thrombectomy

Cardiac Evaluation

• 12-lead ECG

  • Identifies atrial fibrillation, flutter, or other arrhythmias
  • Rules out acute myocardial infarction

• Echocardiography

  • Transthoracic echo (TTE) to evaluate for:
    • Left ventricular thrombus
    • Patent foramen ovale
    • Valvular disease
    • Wall motion abnormalities

• Extended cardiac monitoring

  • 24-hour Holter or longer monitoring for paroxysmal atrial fibrillation
  • Consider implantable loop recorder for cryptogenic stroke

Special Considerations

For Suspected Arterial Dissection

• CTA has high sensitivity (>90%) for detecting arterial dissections 1
• MRA may be useful as a follow-up study to avoid radiation exposure

For Suspected Cerebral Venous Thrombosis

• CTV has comparable accuracy to MRV for diagnosis 1
• MRI with venography is preferred when available and not contraindicated

For Hemorrhagic Stroke

• MRI is essential to evaluate for underlying vascular malformations
• Consider digital subtraction angiography (DSA) if CTA/MRA is negative but clinical suspicion remains high 2

Pitfalls to Avoid

1. Relying solely on CTA for blunt cerebrovascular injury diagnosis

   • CTA has a high false-positive rate (up to 47.9% in some studies) 2
   • Consider confirmatory DSA for equivocal findings

2. Missing cerebral venous thrombosis

   • Always consider venous imaging when infarcts are in atypical locations

3. Inadequate cardiac evaluation

   • Up to 30% of cryptogenic strokes may be due to paroxysmal atrial fibrillation
   • Extended cardiac monitoring beyond 24 hours may be necessary

4. Overlooking the need for repeat vascular imaging

   • Short-interval follow-up imaging (1-3 weeks) may detect changes in vascular injuries that affect management 3

By following this comprehensive diagnostic approach, clinicians can effectively identify the etiology of CVA, guide appropriate treatment, and implement strategies for secondary prevention to reduce morbidity and mortality.