Diagnostic Evaluation for Suspected Stroke

Immediate Imaging Studies

The American Heart Association recommends non-contrast CT or MRI as the first imaging test to differentiate ischemic from hemorrhagic stroke in patients with suspected stroke 1, 3
CTA from aortic arch to vertex should be performed immediately to assess both extracranial and intracranial circulation in patients with suspected stroke 1, 4
The International Journal of Stroke suggests that CT perfusion and multiphase/dynamic CTA should be considered to assess cerebral blood flow and collateral vessels, but must not delay thrombolytic therapy 3

The American College of Cardiology recommends complete blood count with platelets to detect thrombocytopenia, anemia, or polycythemia affecting treatment decisions in patients with suspected stroke 2, 5
Electrolytes and renal function tests, including creatinine and eGFR, should be performed to identify metabolic derangements and guide medication dosing in patients with suspected stroke 1, 2
Coagulation studies, including aPTT and INR, are critical before thrombolytic therapy to identify coagulopathies in patients with suspected stroke 1, 2
Random glucose or HbA1c testing should be performed to exclude hypoglycemia and identify hyperglycemia, which worsens outcomes in patients with suspected stroke 2
Troponin testing should be performed to identify concurrent myocardial infarction or ischemia in patients with suspected stroke 1, 2

A 12-lead ECG is mandatory to assess cardiac rhythm, detect atrial fibrillation, and identify structural heart disease in patients with suspected stroke 1, 3
Extended ECG monitoring up to 30 days is recommended when initial ECG shows no atrial fibrillation but cardioembolic mechanism is suspected in patients with suspected stroke 2, 3, 4
Echocardiogram should be performed when cardiac source is suspected, particularly in young adults, when infectious endocarditis is suspected, or when stroke mechanism remains unidentified in patients with suspected stroke 2, 3, 4

The entire diagnostic evaluation should be completed or underway within 48 hours of symptom onset, with brain imaging and vascular imaging completed according to risk stratification in patients with suspected stroke 1
Highest risk patients should undergo comprehensive evaluation within 24 hours, moderate risk patients within 2 weeks, and lower risk patients within 1 month 1

The American Heart Association recommends never delaying acute treatment while awaiting laboratory results unless there is clinical suspicion of bleeding abnormality, thrombocytopenia, or known anticoagulant use in patients with suspected stroke 2
Vascular imaging should not be skipped, as CTA identifies large vessel occlusions that may benefit from endovascular therapy up to 24 hours from symptom onset in patients with suspected stroke 3
Glucose testing should not be forgotten, as it is the only stroke mimic that requires immediate exclusion before proceeding with other interventions in patients with suspected stroke 2